Severity Of Apoptosis Research Articles

The influence of nitric oxide delivery on the processes of apoptosis, necroptosis and pyroptosis in the renal parenchyma after simulating cardiopulmonary bypass: an experimental study

The objective was to study the effect of the delivery of exogenous nitric oxide on the severity of apoptosis, pyroptosis, and necroptosis of the renal parenchyma after simulating cardiopulmonary bypass and cardiopulmonary bypass with circulatory arrest.Materials and Methods. 24 Altai breed rams were randomized into 4 equal groups. In the CPB and CPB+NO groups, we simulated cardiopulmonary bypass without circulatory arrest. In the CPB+CA and CPB+CA+NO groups, we simulated cardiopulmonary bypass with circulatory arrest. In the CPB+NO, CPB+CA+NO groups, NO was given perioperative in concentration of 80 ppm. In the CPB, CPB+CA groups, we supplied a standard oxygen-air mixture without NO.Results. In the CPB+CA+NO group, the TNF-α concentration was statistically significantly lower: 899 [739; 1019] ng/g compared to the CPB+CA group 1716 [1284; 2201] ng/g, p = 0.026. The remaining markers of programmed cell death did not differ between groups.Conclusions. Perioperative nitric oxide delivery reduces the expression of the extrinsic pathway of apoptosis of renal parenchyma cells in simulating operations with artificial circulation and circulatory arrest. Perioperative nitric oxide delivery at a dose of 80 ppm does not increase the processes of apoptosis, pyroptosis, and necroptosis in renal parenchyma.

Neurogenesis in Brain Neurogenic Niches in Experimental Alzheimer’s Disease at the Presymptomatic Stage of Neurodegeneration

Deciphering the mechanisms of development of neurodegeneration at the presymptomatic stage is an urgent task. It’s solving allows optimizing the methods of early diagnostics and prevention of Alzheimer’s disease (AD). Goal of the study: to study the features of neurogenesis in brain neurogenic niches in experimental Alzheimer’s disease at the presymptomatic stage of neurodegeneration. Modeling of AD in vivo was carried out in experimental animals (male mice, C57BL/6, 8 months old) as follows: the control group, n = 30, animals were injected with 2 µl of a 0.9% NaCl solution in the CA1 field of the hippocampus; the experimental group, n = 30, animals were injected with a 1M solution of oligomerized beta-amyloid 25–35 (Aβ25–35) (2 μl bilaterally). Cognitive impairments have been assessed with the passive avoidance task (PAT). For immunohistochemical studies, we identified the subgranular zone of the hippocampus (SGZ) and the subventricular zone (SVZ) in frozen sections of the brain tissue. We have analyzed the expression of markers – Nestin, Pax6, NeuroD1, VEGFR2, as well as apoptosis (TUNEL protocol) in neurogenic niches. In the period preceding the manifestation of cognitive dysfunction (from 9 to 17 days after intrahippocampal administration of Aβ25–35), we registered multidirectional changes in the expression of markers of neurogenesis, neoangiogenesis and the severity of apoptosis in the SGZ of the hippocampus and in the SVZ. At 9th day since the beginning of development of Alzheimer’s type neurodegeneration, we found elevated expression of Pax6 and VEGFR2 in the SGZ and higher number of Nestin+ cells in the SVZ. Subsequent application of the PAT protocol with the presentation of an aversive stimulus (day 10) or the corresponding context (days 11 and 17) resulted in dynamic changes in the expression of cell markers at different stages of neurogenesis. In sum, аt the presymptomatic stage of the Alzheimer’s type neurodegeneration, SGZ and SVZ show signs of aberrant neurogenesis associated with a disruption in the pool of stem and progenitor cells and suppression of the production of neuroblasts/immature neurons in the period preceding the evident cognitive dysfunction.

Activation of reparative liver regeneration following the combined transplantation of multipotent mesenchymal stromal cells and hepatic stellate cells

Aim. To study the effect of combined transplantation of multipotent mesenchymal stromal and hepatic stellate cells on the reparative liver regeneration.
 Methods. Laboratory mice were given intravenous administration of multipotent mesenchymal stromal and hepatic stellate cells after partial hepatectomy. The mice were divided into four groups: control, experimental 1 (injection of multipotent mesenchymal stromal cells), experimental 2 (co-transplantation of multipotent mesenchymal stromal cells and hepatic stellate cells), the comparison group. Comparison of the experimental groups with the control group and the comparison group was carried out. Each group consisted of 14 animals. The control and experimental groups underwent partial hepatectomy. The experimental mice were injected with the cells into the lateral tail vein 1 hour after the operation. Multipotent mesenchymal stromal cells were administered at a dose of 4 million cells/kg (120 thousand cells/mouse), hepatic stellate cells in the amount of 9 million cells/kg (270 thousand cells/mouse), suspended in 0.2 ml 0.9% NaCl solution. The control group animals were injected with 0.2 ml 0.9% NaCl solution into the lateral tail vein. The comparison group consisted of mice without partial hepatectomy, injected with 0.2 ml 0.9% NaCl solution. To assess reparative regeneration of the liver, morphometric parameters of the liver, blood biochemical parameters on the 3rd and 7th days after partial hepatectomy were studied. The severity of apoptosis was assessed by the immunohistochemical method, the activity of deoxyribonucleic acid (DNA) repair enzymes of the poly (ADP-ribose) polymerases was determined by flow cytometry. The number of micronucleated hepatocytes was also determined. The hepatocyte growth factor (HGF) content was measured by using an enzyme-linked immunosorbent assay in serum. The significance of differences in the compared samples was determined by using the Student's t-test. Statistical data processing was performed by using the SPSS Statistics software version 17.0.
 Results. It was found that the combined transplantation of multipotent mesenchymal stromal and stellate liver cells causes restoration of the activity of alanine aminotransferase (a decrease of 30.3%, p=0.016), aspartate aminotransferase (a decrease of 27.7%, p=0.021), alkaline phosphatase (a decrease of 21.1%, p=0.036), an increase in the protein synthetic function of the liver (increase in albumin level by 36.6%, p=0.009), an increase in hepatocyte growth factor level by 74.3%. These changes were accompanied by the restoration of liver morphometric parameters: there was an increase in the mitotic activity of hepatocytes by 28.7% (p=0.008), the nuclear area of hepatocytes by 26.7% (p=0.006), the number of binucleated hepatocytes by 26.1% (p=0.004), which led to the restoration of liver mass. There was a decrease in the level of apoptosis by 28.8% (p=0.006) and a decrease in the number of micronucleated hepatocytes by 22.7% (p=0.001) compared with the control group, which may be related to an increase in the activity of Poly (ADP-ribose) polymerase repair enzymes detected in the study. The deviations were presented as a difference relative to the indicators of the control group (operated animals that were injected with 0.9% NaCl solution).
 Conclusion. Combined transplantation of multipotent mesenchymal stromal and hepatic stellate cells activates reparative liver regeneration after partial hepatectomy.Keywords: multipotent mesenchymal stromal cells, MSC, hepatic stellate cells, HSC, liver regeneration, partial hepatectomy.

N-acetylcysteine supplementation did not reverse mitochondrial oxidative stress, apoptosis, and inflammation in the salivary glands of hyperglycemic rats

Background/objectivesPrevious studies have shown that N-acetylcysteine (NAC) supplementation with the simultaneous inclusion of HFD prevents salivary glands from oxidative stress and mitochondrial dysfunction. In this experiment, we examined if NAC supplementation could reverse the harmful effect of HFD on mitochondrial function, reduce the severity of apoptosis, and the activity of pro-oxidative enzymes in the salivary glands of rats with confirmed hyperglycemia.Subjects/methodsWistar rats were fed the standard or high-fat (HFD) diet for 10 weeks. After 6 weeks of the experiment, HFD rats were diagnosed with hyperglycemia and for the next 4 weeks, the animals were given NAC intragastrically. In the mitochondrial fraction of the parotid (PG) and submandibular salivary glands (SMG), we assessed redox status, inflammation, and apoptosis.ResultsThe inclusion of NAC increased the activity of mitochondrial complexes I and II + III as well as decreased the concentration of interleukin-1β, tumor necrosis factor α, and caspase-3, but only in the parotid glands of rats with hyperglycemia compared to the HFD group. However, N-acetylcysteine supplementation did not reduce the activity of caspase-9 or the Bax/Bcl-2 ratio in PG and SMG mitochondria. In both salivary glands we observed reduced activity of cytochrome c oxidase, NADPH oxidase, and xanthine oxidase, as well as hindered production of ROS and lower ADP/ATP radio, but the levels of these parameters were not comparable to the control group.ConclusionsWe demonstrated that NAC supplementation restores the glutathione ratio only in the mitochondria of the submandibular salivary glands. The supply of NAC did not significantly affect the other measured parameters. Our results indicate that NAC supplementation provides little protection against free radicals, apoptosis, and inflammation in the salivary gland mitochondria of HFD rats. Stimulated salivary secretion in hyperglycaemic rats supplemented with NAC seems to be closely related to mitochondrial respiratory capacity and appropriate ATP level.

PUMA-mediated epithelial cell apoptosis promotes Helicobacter pylori infection-mediated gastritis

The molecular mechanism responsible for Helicobacter pylori infection-mediated gastritis and carcinogenesis is not yet clear. Increased evidence suggests that chronic gastritis and elevated gastric epithelial cell (GEC) apoptosis are crucial events during stomach carcinoma transformation. PUMA is a potent proapoptotic Bcl-2 protein and mediates acute tissue injury. In this study, we aimed to investigate the role of PUMA in GEC apoptosis and inflammation induced by H. pylori infection. As a result, we found that PUMA expression was elevated in gastritis tissues compared with uninvolved tissues, and it was correlated with the severity of apoptosis and gastritis. In mice, PUMA mRNA and protein were markedly induced in GECs upon induction of gastritis by H. pylori. PUMA-deficient mice were highly resistant to apoptosis and gastritis induced by H. pylori. Furthermore, the transcription factor NF-κB p65 binds to PUMA promoter to activate PUMA transcription after H. pylori infection. In addition, NF-κB inhibitor could rescue H. pylori-induced apoptosis and gastritis. Finally, H. pylori-induced activation of p-p65 and PUMA was mediated via Toll-like receptor 2 (TLR2) and blocked in TLR2 knockout mice. Taken together, these results verified the pro-inflammatory effect of PUMA in H. pylori-infected gastric tissue. Moreover, TLR2/NF-κB-mediated transcriptional regulation of PUMA contributes to the pathogenesis of H. pylori-infected gastritis.

The protective effects of salvianolic acid A against hepatic ischemia-reperfusion injury via inhibiting expression of toll-like receptor 4 in rats.

IntroductionIschemia-reperfusion injury (IRI) is a serious complication of hepatectomy and liver transplantation. The aim of this study was to evaluate the protective effects of salvianolic acid-A (Sal-A) against IRI-induced hepatocellular injury.Material and methodsForty rats were randomly divided into the following four groups: (1) sham group, (2) IR group, (3) Sal-A(10) group and (4) Sal-A(20) group. After 90 min of ischemia and 6 h of reperfusion, serum alanine aminotransferease (ALT) and apartate aminotransferase (AST) levels were measured; the amounts of malondialdehyde (MDA) and superoxide dismutase (SOD) in the liver tissue were determined; the expression of Bcl-2 and caspase-3 was detected and the severity of apoptosis, inflammation and pathological alterations were evaluated. Also apoptosis and mRNA and protein levels of TLR4 (toll-like receptor 4) were tested.ResultsThe serum aminotransferases, hepatic MDA concentration, and apoptotic cells in the IR group were significantly higher than in the sham group (p < 0.01), whereas the Sal-A group values were lower than in the IR group (p < 0.05). Compared with the IR group, the Sal-A groups had significantly higher Bcl-2 expression and downregulated cleaved caspase-3 expression in liver tissue. Moreover, increased mRNA and protein levels of TLR4 in IR rats and Sal-A could improve the increased mRNA and protein levels of TLR4.ConclusionsSal-A had a synergistically protective effect on the liver tissue against IRI that might be due to decreased oxidative stress, inflammation, hepatocellular apoptosis and include, at least in part, the regulation of TLR4.

Type 2 porcine reproductive and respiratory syndrome virus infection increases apoptosis at the maternal-fetal interface in late gestation pregnant gilts.

The pathogenesis of fetal death associated with porcine reproductive and respiratory syndrome (PRRS) is hypothesized to be a consequence of PRRS virus-induced apoptosis at the maternal-fetal interface (MFI). The objectives of this study were to evaluate distribution and degree of apoptosis in the uterine and fetal placental tissues during the experimental type 2 PRRS virus (PRRSV) infection and determine associations between apoptosis at the MFI, PRRSV RNA concentration and antigen staining intensity, PRRSV-induced microscopic lesions, and fetal preservation status. A total of 114 naïve, high-health pregnant gilts were inoculated with type 2 PRRSV on gestation day 85±1 with euthanasia 21 days later; 19 sham-inoculated gilts served as controls. Two hundred and fifty samples of uterine tissue with fetal placenta were selected based on negative, low PRRSV RNA, and high PRRSV RNA concentration (0, < or > 2.7 log10 copies/mg, respectively). TUNEL assay was used to detect apoptosis in the endometrium and at the MFI. PRRSV RNA concentration and numbers of PRRSV immunopositive cells in uterine and placental tissue were positively associated with the severity of apoptosis in the endometrium and the MFI (P<0.001, P<0.05 and P<0.001, respectively). The number of TUNEL positive cells at the MFI was also positively associated with the severity (P<0.001) of vasculitis, but not total numbers of inflammatory cells in the endometrium. Increased numbers of TUNEL positive cells at the MFI were associated with PRRSV load in the fetal thymus, and greater odds of meconium staining of the fetus at 21 days post infection (P<0.001 for both). These findings suggest an important role of apoptosis in the pathogenesis of uterine epithelial and trophoblastic cell death at the MFI. Moreover, apoptosis at the MFI is significantly associated with fetal demise during in utero type 2 PRRSV infection.

Macro- and Microelement Content and Other Properties of Chaenomeles japonica L. Fruit and Protective Effects of Its Aqueous Extract on Hepatocyte Metabolism

This growing interest in the cultivation of Japanese quince Chaenomeles japonica L. results from the potentially beneficial properties of its fruit. Fresh fruits are very firm and too acidic to eat raw, but their bioactive components, distinctive aroma, and high amount of dietary fiber make the fruits well suited for industrial processing. However, not all the properties of the fruit have been investigated. For example, there are no comprehensive reports about the mineral content or potentially harmful effects on liver metabolism. Hence, the purpose of our study was to examine fresh Japanese quince fruit in terms of (1) ascorbic acid, oxalate, fiber, macro- and micronutrients, dry matter, extract, total acidity, antioxidant activity, and phenolic compound levels; and (2) the effect of its extract on in vitro hepatocyte metabolism, measured by the concentration of lipid peroxides (LPO) and reactive oxygen species (ROS) and the severity of apoptosis and necrosis. The fruit of C. japonica had high levels of macro- and microelements, ascorbic acid, phenolic compounds, fiber, and low oxalate levels. Our analysis of macro- and microelements showed that the average content of Fe was 0.516 mg/g, Cu 0.146 mg/g, Zn 0.546 mg/g, Mg 16.729 mg/g, and Ca 22.920 mg/g of fresh fruit. A characteristic feature of the fresh fruit of C. japonica is a high level of polyphenols, which—combined with a high content of vitamin C—affect their high antioxidant potential. In the tested hepatocyte cultures incubated with extract of the Japanese quince, we observed a significant decrease in the concentration of lipid peroxides compared to the control. There were also no signs of increased formation of ROS in the mitochondria of hepatocytes incubated with the extract of quince. Malondialdehyde was strongly negatively correlated with the concentration of Japanese quince extract, which indicates the hepatoprotective properties of Japanese quince. In addition, our analysis of confocal microscopy images showed that the hepatocytes incubated with the extract of Japanese quince at any concentration did not show any signs of apoptosis or necrosis. The aqueous extract of quince fruit has antioxidative and antiapoptotic hepatocytes, thus exerting a hepatoprotective effect.

Studying Variation in Cell Apoptosis Caused by Corticosteroids in Thymus of the Rat

Background and purpose: Apoptosis or planned death of cells is the main mechanism in completion and hemostasis of mature tissues to terminate useless, contaminated, and mutated/damaged cells through internal suicide pathways. One of the agents that creates apoptosis signals is glucocorticoids. As the representative of corticosteroid drugs, dexamethasone can induce apoptosis via internal endonuclease. Therefore, dexamethasone was used as a synthetic glucocorticoid in rats. The effects of dexamethasone on thymocyte of rats, morphological features of apoptotic cells, and the relationship between drug dosage and severity of apoptosis were examined. Methodology: A treatment group with four subgroups (each with five rats) namely T-a, T-b- T-c, and T-a was formed and received IP dexamethasone of 0.5, 1.5, 2.5, 3.5mg per one-kilogram body weight respectively. In addition, a control group with similar subgroups was formed. Thymus gland of the subjects of both groups was removed six hours after injection. The samples were examined using electron and optical microscopes.Findings: Examinations by optical microscope revealed round or elliptic apoptotic cytoplasmic bodies with or without nucleus basophil materials along with crescentic bodies of chromatin on the apoptotic cells. In addition, electronic microscope images reveled marginal augmentation of nucleus chromatin in osmiophilic forms detached from nucleus fibrillary centers along with a disordered cellular region, endoplasmic reticulum complication, and nucleus fragmentation. There was a direct and significant relationship between the dosage of the drug and the severity of apoptosis.Conclusion and Recommendations: The results showed that standard and higher dosages of corticosteroid stimulated DNA fragmentation in thymocytes and apoptosis of thymocytes induced by corticosteroid is a calcium-depended process.&#x0D;

Biomarkers of cellular apoptosis and necrosis in donor myocardium are not predictive of primary graft dysfunction.

Primary graft dysfunction (PGD) is a life-threatening complication among heart transplant recipients and a major cause of early mortality. Although the pathogenesis of PGD is still unclear, ischemia/reperfusion injury has been identified as a predominant factor. Both necrosis and apoptosis contribute to the loss of cardiomyocytes during ischemia/reperfusion injury, and this loss of cells can ultimately lead to PGD. The aim of our prospective study was to find out whether cell death, necrosis and apoptosis markers present in the donor myocardium can predict PGD. The prospective study involved 64 consecutive patients who underwent orthotopic heart transplantation at our institute between September 2010 and January 2013. High-sensitive cardiac troponin T (hs-cTnT) as a marker of minor myocardial necrosis was detected from arterial blood samples before the donor's pericardium was opened. Apoptosis (caspase-3, active + pro-caspase-3, bcl-2, TUNEL) was assessed from bioptic samples taken from the right ventricle prior graft harvesting. In our study, 14 % of transplant recipients developed PGD classified according to the standardized definition proposed by the ISHLT Working Group. We did not find differences between the groups in regard to hs-cTnT serum levels. The mean hs-cTnT value for the PGD group was 57.4+/-22.9 ng/l, compared to 68.4+/-10.8 ng/l in the group without PGD. The presence and severity of apoptosis in grafted hearts did not differ between grafts without PGD and hearts that subsequently developed PGD. In conclusion, our findings did not demonstrate any association between measured myocardial cell death, necrosis or apoptosis markers in donor myocardium and PGD in allograft recipients. More detailed investigations of cell death signaling pathways in transplanted hearts are required.

Neuroprotective effect of levetiracetam on hypoxic ischemic brain injury in neonatal rats

Hypoxic-ischemic brain injury that occurs in the perinatal period is one of the leading causes of mental retardation, visual and auditory impairment, motor defects, epilepsy, cerebral palsy, and death in neonates. The severity of apoptosis that develops after ischemic hypoxia and reperfusion is an indication of brain injury. Thus, it may be possible to prevent or reduce injury with treatments that can be given before the reperfusion period following hypoxia and ischemia. Levetiracetam is a new-generation antiepileptic drug that has begun to be used in the treatment of epilepsy. The present study investigated the effects of levetiracetam on neuronal apoptosis with histopathological and biochemical tests in the early period and behavioral experiments in the late period. This study showed histopathologically that levetiracetam reduces the number of apoptotic neurons and has a neuroprotective effect in a neonatal rat model of hypoxic-ischemic brain injury in the early period. On the other hand, we demonstrated that levetiracetam dose dependently improves behavioral performance in the late period. Based on these results, we believe that one mechanism of levetiracetam's neuroprotective effects is due to increases in glutathione peroxidase and superoxide dismutase enzyme levels. To the best of our knowledge, this study is the first to show the neuroprotective effects of levetiracetam in a neonatal rat model of hypoxic-ischemic brain injury using histopathological, biochemical, and late-period behavioral experiments within the same experimental group.

DYNAMICS OF CONCENTRATION OF APOPTOSIS SERUM MARKERS IN ASSESSMENT OF PROGNOSIS OF CHRONIC KIDNEY DISEASE IN CHILDREN

Aim: to investigate sFas-receptor and its ligand, sFas-L, cytochrome C and annexin V as the apoptotic markers in children with CKD to determine the renal cell apoptosis role in the progression of a renal disease. Patients and methods: 68 children with CKD 1–3 from 3 to 17 years were examined. Results: sFas-R, sFas-L, annexin V significant differed from normal value at all stages of CKD. Cytochrome C level was significantly higher than normal in children with CKD1. But tended to increase at and 2 and 3 stages correspondingly. Significant correlation was determinated between proteinuria and the combination of all four markers. Сomparing serum levels of apoptosis markers in children with non-immune disorders without renal dysfunction treated and iACE not treated and in patients with CKD-2 t a significant excess of the level of sFas-R in patients without iACE therapy was found. Conclusions: Fas-mediated and mitochondrial programmed cell death are implicated in development and progression of CKD. ACE inhibitors reduced the severity of apoptosis, primarily by inhibiting the activity of its Fas-mediated pathway.

Effects of ischemia and reperfusion on production of nitrotyrosine, activation of eosinophils, and apoptosis in the large colonic mucosa of horses

To assess the effects of ischemia and reperfusion on indicators of oxidative stress, activation of eosinophils, and apoptosis in the large colonic mucosa of horses. 40 horses. In 1 or two 20-cm-long segments of the pelvic flexure, ischemia was induced for 1 or 2 hours followed by no reperfusion or 30 minutes and 18 hours of reperfusion in anesthetized horses. Mucosal specimens were collected before (controls; n = 20 horses) and after each period of ischemia, and full-thickness tissue samples were collected after each period of reperfusion. Sections of colonic tissues were stained for histomorphometric analysis or assessment of eosinophil accumulation. Nitrotyrosine was identified immunohistochemically, and severity of apoptosis was determined via the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling method. Numbers of mucosal eosinophils were similar before induction of ischemia, after ischemia, and after ischemia-reperfusion. Eosinophil nitrotyrosine production increased significantly during ischemia and continued through 30 minutes of reperfusion; production was decreased at 18 hours of reperfusion but remained greater than that of the controls. In other leukocytes, nitrotyrosine generation peaked at 1 hour of ischemia and again at 18 hours of reperfusion. Compared with control findings, epithelial apoptosis increased gradually at 1 through 2 hours of ischemia with no further progression after reperfusion. Results suggested that resident eosinophils in the large colon of horses react to mucosal injury from ischemia and reperfusion and may undergo oxidative stress under those conditions. Epithelial apoptosis could contribute to tissue damage.

ROLE OF MECHANISMS OF VIOLATIONS proliferation and apoptosis in morphogenesis fibrocystic disease of breast

In this paper, an analysis of published data shows the significant role of apoptosis during ontogenesis of the breast, the neoplastic transformation of tissues and the likely importance of these processes in the mechanism of hyperplastic processes and fibrocystic disease of breast cancer. However, it remains unresolved the question of what biological markers may serve as quantitative indicators of proliferative activity of breast tissue, as well as objectively reflect the severity of apoptosis and the activity of genes - tumor suppressor. Studying the expression of molecules of products of genes-regulators of cell proliferation and apoptosis is of great scientific interest because it can probably afford to hold detalizovannye risk assessment for breast cancer, followed by the prediction of the disease

The Strategy of Combined Ischemia Preconditioning and Salvianolic Acid-B Pretreatment to Prevent Hepatic Ischemia-Reperfusion Injury in Rats

Ischemia-reperfusion injury (IRI) is a serious complication of liver surgery, especially for extended hepatectomy and liver transplantation. The aim of this study was to evaluate the protective effect of combined ischemic preconditioning (IPC) and salvianolic acid-B (Sal-B) pretreatment against IRI-induced hepatocellular injury. Sixty male Wistar rats weighing around 200 g were randomized into five groups (n=12): sham group: only anesthesia and laparotomy; IR group: 90 min sustained ischemia by blocking the left ortal vessels; IPC group: 10 min ischemia and 10 min reperfusion prior to the sustained ischemia; Sal-B group: 10 mg/kg injection of Sal-B intravenously 10 min prior to the sustained ischemia; IPC+Sal-B group: same IPC procedure as in IPC group, but proceeded by intravenous administration of Sal-B 10 min prior to sustained ischemia. After 5 h of reperfusion, serum levels of ALT and AST were measured; the amount of malondialdehyde (MDA) and adenine nucleotides in liver tissue was determined; the expression of Bcl-2 and caspase-3 was detected by immunofluorescent and western blotting techniques; the severity of apoptosis and pathological alterations was evaluated by TUNEL and H&E staining, respectively. The serum aminotransferases, hepatic MDA concentration, and apoptotic index in groups IPC, Sal-B, and IPC+Sal-B were significantly lower than those in the IR group (P<0.001), while the IPC+Sal-B group had the lowest values among these groups (P<0.05). Compared with the IR group, groups IPC and Sal-B not only had statistically higher ATP levels and energy charge (EC) values (P<0.01), but also had upregulated Bcl-2 expression and downregulated cleaved caspase-3 expression in liver tissue. All these effects were further augmented in the IPC+Sal-B group. Liver histopathological findings were consistent with these results. Based on these results, the combined IPC and Sal-B pretreatment had a synergistically protective effect on liver tissue against IRI, which might be due to decreased post-ischemic oxidative stress, improved energy metabolism, and reduced hepatocellular apoptosis.

Histological and biochemical alterations in early-stage lobar ischemia-reperfusion in rat liver

To investigate the structural and biochemical changes in the early stage of reperfusion in the rat livers exposed to lobar ischemia-reperfusion (IR). The median and left lobes of the liver were subjected to 60 min ischemia followed by 5, 10, 30, 45, 60 and 120 min reperfusion. Blood samples were taken at different time intervals to test enzyme activities and biochemical alterations induced by reperfusion. At the end of each reperfusion period, the animals were killed by euthanasia and tissue samples were taken for histological examination and immunohistochemistry. Cell vacuolation, bleb formation and focal hepatitis were the most important changes occur during ischemia. While some changes including bleb formation were removed during reperfusion, other alterations including portal hepatitis, inflammation and the induction of apoptosis were seen during this stage. The occurrence of apoptosis, as demonstrated by apoptotic cells and bodies, was the most important histological change during reperfusion. The severity of apoptosis was dependent on the time of reperfusion, and by increasing the time of reperfusion, the numbers of apoptotic bodies was significantly enhanced. The amounts of lactate dehydrogenase, alanine aminotransferase, aspartate aminotransferase, creatinine and urea were significantly increased in serum obtained from animals exposed to hepatic IR. Inflammation and subsequent apoptotic cell death were the most important changes in early-stage hepatic reperfusion injury, and the number of apoptotic bodies increased with time of reperfusion.

Mitomycin C, Ceramide, and 5-Fluorouracil Inhibit Corneal Haze and Apoptosis After PRK

To investigate the effects of mitomycin C (MMC), ceramide, and 5-fluororacil (5-FU) on haze after photorefractive keratectomy (PRK) and exposure to ultraviolet B (UVB) radiation. The right eyes of 42 New Zealand white rabbits were treated with PRK to correct -10 diopter with a 5-mm optical zone. Sponges soaked in 0.02% MMC, 10 or 40 micromol/L ceramide, or 0.5% 5-FU were applied to the right eyes of 6 rabbits each, and a tarsorrhaphy was performed. Eight weeks after complete healing, topical 0.02% MMC or 0.5% 5-FU was applied twice daily to the right eyes of 6 rabbits that had previously received PRK but no topical medication. The control group of 6 rabbits was treated only with PRK. Three weeks after PRK, all the laser-treated eyes were exposed to 100 mJ/cm UVB radiation. Corneal haze was assessed biomicroscopically every 2 weeks using the Fantes scale. Eyes were enucleated 2, 7, and 13 weeks after PRK, and tissue specimens were stained with hematoxylin and eosin and with Apostain. Corneal haze was observed in all rabbits after PRK and was aggravated by UVB irradiation. When applied immediately after PRK, MMC induced corneal opacity and apoptosis of keratocytes, but, at later times, this reagent significantly suppressed opacity, Apostain-positive keratocytes and reactivation of keratocytes, even after UVB irradiation. In contrast, ceramide and 5-FU suppressed corneal opacity after PRK, but this effect was not sustained after UVB irradiation. MMC is a potent inhibitor of haze induced by PRK and UVB irradiation. Throughout the process of corneal wound healing, the severity of apoptosis and reactivation of keratocytes was closely correlated with haze formation.

The role of nitric oxide in reflux nephropathy.

Reflux nephropathy (RN) is recognized as a major cause of end-stage renal failure in children and young adults. Inhibition of nitric oxide (NO) exacerbates and enhanced production ameliorates tubulointerstitial fibrosis (TIF) in experimental obstructive uropathy. NO is synthesised by NO synthase (NOS), three distinct isoforms of which have been identified: inducible (iNOS), endothelial (eNOS), and neuronal (nNOS). It has been reported that iNOS induces immunologic injury to glomerular cells and enhances accumulation of extracellular matrix in the glomerulus and tubulointerstitial space. Furthermore, it has been suggested that nNOS and eNOS have beneficial effects in ameliorating TIF. We investigated the expression of different isoforms of NOS in severe refluxing kidneys in order to further understand the pathogenesis of RN in kidney specimens from nine children with severe RN obtained at nephrectomy. Control material included normal kidney specimens from three adult patients undergoing partial nephrectomy for small kidney tumours. Histochemistry for NO was performed using nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase. Single-label immunofluorescence histochemistry was carried out using polyclonal antibodies to nNOS, iNOS, eNOS, and transforming growth factor (TGF)-beta 1 employing laser-scanning confocal microscopy. The TUNEL method was used to assess tubular apoptosis. Strong NADPH staining was observed in the proximal tubules of RN kidneys compared to controls, where there was weak staining. Control kidneys demonstrated weak immunoreactivity for iNOS in the proximal tubules and a lack of immunoreactivity for nNOS and eNOS. RN kidneys demonstrated strong immunoreactivity for nNOS in the tubulointerstitial space, for eNOS in the glomerulus, and for iNOS in the glomerulus and proximal tubules. Strong immunoreactivity for TGF beta 1 was seen in the glomerulus and proximal tubules identical to iNOS. Increased immunoreactivity for iNOS and TGF-beta 1 strongly correlated with the severity of apoptosis in RN. Our data demonstrate that NO derived from nNOS, iNOS, and eNOS is strongly expressed in RN. The selective shunting of NO via iNOS may induce renal fibrosis in RN. The upregulation of nNOS and eNOS in RN appears to be a compensatory mechanism of ameliorating TIF.

Apoptosis-induced structural changes in leukemia cells identified by IR spectroscopy

Apoptotic changes induced in the leukemia cell line CEM by treatment with the chemical etoposide were investigated by IR spectroscopy. Characteristic band alterations were identified in the apoptotic cells arising from cellular protein, lipid and DNA. Besides general changes such as an increase in lipid content and a decrease in the amount of detectable DNA, there were specific changes that affected the secondary structure of proteins in the apoptotic leukemia cells, i.e. the dominant protein structure shifts from β-sheet in the control cells to unordered coil in the apoptotic cells. The student's t-test was applied to the spectral range 1500–1700cm−1 in order to determine the significant differences of protein structure between control and etoposide treated cells at various time points. A temporal relationship was found between the spectrally significant differences of the protein structure in the apoptotic cells and the severity of apoptosis. The IR spectral changes of protein structure also correlate well with the activity of caspase-3, an important proteolytic enzyme in apoptosis. This preliminary study suggests that IR spectroscopy could possibly be used to monitor and quantitate apoptosis in leukemia cells.

APOPTOSIS IN CARDIAC TRANSPLANT REJECTION

Apoptosis occurs in human cardiac allograft rejection and may occur with all degrees of rejection and even in its absence. The prevalence and severity of apoptosis is determined predominantly by the intensity of macrophage infiltration and may be mediated by NO-related mechanisms. Apoptosis of interstitial, endothelial, and inflammatory cells is also present in heart allografts and may influence the degree and extent of vascular injury contributing to allograft rejection. Ongoing apoptosis of inflammatory cells suggests an immunoregulatory role. Studies of the involvement of NO in myocyte damage and Fas-FasL interactions in peripheral tolerance have raised the exciting possibility that these pathways can be exploited in a beneficial way. Further understanding of the role of apoptosis and the cellular and biochemical mechanisms that are involved in cardiac myocyte death and in inflammatory, endothelial, and interstitial cell death may provide insights into therapeutic modalities to suppress allograft rejection and vasculopathy.