Reproductive toxicity of cadmium in pubertal male rats induced by cell apoptosis.

Cadmium (Cd) is a heavy metal that is widely present in modern industrial production. It is a known, highly toxic environmental endocrine disruptor. Long-term exposure to Cd can cause varying degrees of damage to the liver, kidney, and reproductive system of organisms, especially the male reproductive system. This study aimed to explore the mechanism of Cd toxicity in the male reproductive system during puberty. Eighteen healthy 6-week-old male Sprague-Dawley rats were randomly divided into three groups (control group, low-dose group, and high-dose group) according to their body weight, with six in each group. Cd (0, 1, and 3 mg/kg/day) was given by gavage for 28 consecutive days. The results showed that Cd exposure to each dose group caused a decrease in the testicular organ coefficient and sperm count, compared with the control group. Cd exposure resulted in significant changes in testicular morphology in the 3 mg/kg/day Cd group. In the 1 and 3 mg/kg/day Cd groups, serum testosterone decreased and apoptosis of testicular cells increased significantly (p < 0.05). In addition, compared with the control group, the activity of glutathione peroxidase and superoxide dismutase in each Cd exposure dose group decreased, but the content of malondialdehyde in the high-dose, 3 mg/kg/day Cd treatment group significantly increased (p < 0.05). Although Cd exposure caused an increase in the messenger RNA (mRNA) levels of Bcl-2, Caspase-3 and Caspase-9 in the testicular tissues (p < 0.05), Bcl-2 expression was unchanged (p > 0.05). The expression level of Akt mRNA in testicular tissue of rats in the high-dose 3 mg/kg/day Cd group was increased (p < 0.05). Our data suggest that Cd affected testosterone levels, and apoptosis was observed in spermatids.

Structural and chemical role of mesenchymal stem cells and resveratrol in regulation of apoptotic -induced genes in Bisphenol-A induced uterine damage in adult female albino rats.

The probable beneficial effects of mesenchymal stem cells (MSCs) and resveratrol were assessed in an experimental model of Bisphenol-A (BPA)-evident uterine damage in rats. Thirty-five albino rats were involved and equally divided into five groups: Group I: negative control rats received usual diet, Group II: positive control rats received BPA by oral gavage for 15 days, Group III: BPA-treated rats received single oral gavage of resveratrol daily for two weeks, Group IV: BPA-treated rats received a single intravenous dose of MSCs and Group V: BPA-treated rats received combined treatment of resveratrol and MSCs. Oxidative stress markers, apoptosis-related genes, and gonadal hormones were assessed. Histological and immunohistochemical examination of uterine tissue was conducted for TGF-ß 1. Caspases-3, 8, and 9 (Casp3, Casp8, Casp9) genes were assessed in uterine tissues by quantitative real-time PCR. Results revealed that BPA induced significant changes in the endometrial tissue, inflammatory cell infiltration, focal blood extravasation, increase in collagen fibers, decrease in PAS staining, and increase in TGF-ß 1 immunoreactivity. BPA also induced a significant increase in oxidative stress markers; malondialdehyde (MDA), SOD, CAT, and apoptosis-related genes. BPA induced a significant change in blood levels of gonadal hormones; a significant increase in FSH and a significant decrease in estradiol (E2) and progesterone (P). Treatment with either resveratrol, MSCs, or a combination of them resulted in significant enhancement of histological findings, restoration of gonadal hormones to near-normal levels, and a significant decrease in oxidative stress markers and apoptosis genes. Combined treatment with resveratrol and MSCs demonstrated more significant therapeutic effects as regard to the studied parameters in association with rat groups treated with either MSCs or resveratrol separately.

Pathogenic Salmonella weakens avian enriched blood monocytes through ATP depletion, apoptosis induction and phagocytosis inefficiency.

Salmonella enterica Subsp enterica serovar Typhimurium (S. Typhimurium, ST) is one of the most important serovars of the genus Salmonella in human and animals. Because of its intracellular tropism, monocytes/macrophages are pivotal in killing of Salmonella serovars; they are also responsible for transporting of ST to extra-intestinal organs. To investigate the effect of the ST on the functions of avian innate immune cells, almost homogeneous enriched monocytes (EMo) were isolated from peripheral blood mononuclear cells of 2-3 weeks-old of healthy broilers. The EMo were then divided in three groups: control (media only), treatments (challenged with ST clinical isolates) and [doxorubicin (Dox), specifically as positive control for EMo apoptosis] groups. Cellular-molecular damage caused by ST in EMo was assessed with bioluminescence (for caspase-3, 7, and 9 activities and intracellular ATP content), chemiluminescence (for pro/anti-oxidant capacities) and flow cytometry (for apoptosis/necrosis). Further, phagocytosis capacity of post-ST challenged EMo was assessed using a flow cytometry-based internalisation of FITC-loaded polystyrene microparticles. Like the effects of Dox, in post-ST challenged EMo much higher caspase-3, 7 and 9 activities and ATP depletion along with decreased phagocytosis capacity and anti-oxidant load were observed. The results herein indicate that ST weakens EMo particularly through caspases activation/apoptosis. These findings can open a new window on the molecular aspects of Salmonella-macrophage interactions and immunopathology/pathogenicity of salmonellosis in animals especially avian species.

Development of Activity-Based Reporter Gene Technology for Imaging of Protease Activity with an Exquisite Specificity in a Single Live Cell.

Imaging of an active protease with an exquisite specificity in the presence of highly homologous proteins within a living cell is a very challenging task. Herein, we disclose a new method called "Activity-based Reporter Gene Technology" (AbRGT). This method provides an opportunity to study the function of "active protease" with an unprecedented specificity. As a proof-of-concept, we have applied this method to study the function of individual caspase protease in both intrinsic and extrinsic apoptosis signaling pathways. The versatility of this method is demonstrated by studying the function of both the initiator and effector caspases, independently. The modular fashion of this technology provides the opportunity to noninvasively image the function of cathepsin-B in a caspase-dependent cell death pathway. As a potential application, this method is used as a tool to screen compounds that are potent inhibitors of caspases and cathepsin-B proteases. The fact that this method can be readily applied to any protease of interest opens up huge opportunities for this technology in the area of target validation, high-throughput screening, in vivo imaging, diagnostics, and therapeutic intervention.

Semicarbazone derivatives as promising therapeutic alternatives in leishmaniasis.

In the present study, we investigated the in vitro and in vivo leishmanicidal activity of synthetic compounds, containing a semicarbazone scaffold as a peptide mimetic framework. The leishmanicidal effect against amastigotes of Leishmania amazonensis was also evaluated at concentration of 100 µM-0.01 nM. The derivatives 2e, 2f, 2g and 1g, beyond the standards miltefosine and pentamidine, significantly diminished the number of L. amazonensis amastigotes in macrophages. These derivatives were also active against amastigotes of L. braziliensis. As 2g presented potent leishmanicidal activity against the amastigotes of L. amazonensis in macrophages, we also investigated the in vivo leishmanicidal activity of this compound against L. amazonensis. Approximately 105L. amazonensis promastigotes were subcutaneously inoculated into the dermis of the right ear of BALB/c mice, which were subsequently treated with 2g (p.o. or i.p.), miltefosine (p.o.) or glucantime (i.p.) at 30 µmol/kg/day x 28 days. Thus, a similar reduction in the lesion size was observed after the administration of 2g through oral (63.7 ±â€¯10.1%) and intraperitoneal (61.8 ±â€¯3.7%) routes. A larger effect was observed after treatment with miltefosine (97.7 ±â€¯0.4%), and glucantime did not exhibit activity at the dose administered. With respect to the ear parasite load, 2g diminished the number of parasites by p.o. (30.5 ±â€¯5.1%) and i.p. (33.3 ±â€¯4.3%) administration. In addition, 2g induced in vitro apoptosis, autophagy and cell cycle alterations on L. amazonensis promastigotes. In summary, the derivative 2g might represent a lead candidate for antileishmanial drugs, as this compound displayed pronounced leishmanicidal activity.

Evolution and structural diversity of metacaspases.

Caspases are metazoan proteases, best known for their involvement in programmed cell death in animals. In higher plants genetically controlled mechanisms leading to the selective death of individual cells also involve the regulated interplay of various types of proteases. Some of these enzymes are structurally homologous to caspases and have therefore been termed metacaspases. In addition to the two well-studied metacaspase variants found in higher plants, type I and type II, biochemical data have recently become available for metacaspases of type III and metacaspase-like proteases, which are present only in certain algae. Although increasing in vitro and in vivo data suggest the existence of further sub-types, a lack of structural information hampers the interpretation of their distinct functional properties. However, the identification of key amino acid residues involved in the proteolytic mechanism of metacaspases, as well as the increased availability of plant genomic and transcriptomic data, is increasingly enabling in-depth analysis of all metacaspase types found in plastid-containing organisms. Here, we review the structural distribution and diversification of metacaspases and in doing so try to provide comprehensive guidelines for further analyses of this versatile family of proteases in organisms ranging from simple unicellular species to flowering plants.

Techniques for the Study of Apoptosis in Bone.

Osteocyte apoptosis has been associated with a number of clinical conditions in bone and with the targeted turnover of specific skeletal areas. There has been great interest in the identification of the mechanisms by which apoptosis is regulated in bone and in the biological role that this process plays in bone metabolism and associated bone disease or loss of structural integrity. Here we describe several methods for the detection of apoptosis in bone sections and in bone cell cultures.

Measuring the Activation of Cell Death Pathways upon Inhibition of Metabolism.

Nutrient starvation or inhibition of cellular metabolism can induce cancer cell death. This can be measured by a variety of methods. We describe here four simple methods to measure cell death in culture by using microscopy, western blot, and flow cytometry. We also provide tools to differentiate between different forms of cell death like apoptosis and necrosis by using chemical inhibitors.

Bixin Triggers Apoptosis of Human Hep3B Hepatocellular Carcinoma Cells: An Insight to Molecular and IN SILICO Approach.

Hepatocellular carcinoma (HCC) is the most common liver cancer and is known to be resistant to conventional chemotherapy. The use of herbal medicine and supplements has increased over recent decades following side effects and resistant to conventional chemotherapy. The seeds of Bixa orellana L. commonly known as annatto have recently gained scientific attention due to presence of a carotenoid bixin for its substantial anticancer properties. However, molecular mechanisms underlying bixin-induced apoptosis are still unclear. Treatment of bixin significantly decreased the number of Hep3B cells and morphological study revealed the change in cellular and nuclear morphology that trigger the events of apoptosis confirmed by annexin V/PI staining. Further DCFDA and rhodamine 123 spectrofluorimetry study showed elevation in reactive oxygen species (ROS) production and loss of mitochondrial membrane potential (MMP), respectively. ROS production caused DNA damage and apoptosis was marked by cell cycle arrest, up-regulation of Bax and FasL protein as well as cleavage of caspase-9, caspase-8 and caspase-3 protein. Docking study with pro-apoptotic molecule Bax and surface Fas ligand exhibited energetically favourable binding interaction. Collectively, these results suggest that bixin capable of modulating the extrinsic and intrinsic molecules of apoptosis indicating its potential for development of promising candidate for hepatocellular carcinoma.

Evidence supporting oxidative stress in a moderately affected area of the brain in Alzheimer's disease.

The pathogenesis of Alzheimer's disease (AD) remains to be elucidated. Oxidative damage and excessive beta-amyloid oligomers are components of disease progression but it is unclear how these factors are temporally related. At post mortem, the superior temporal gyrus (STG) of AD cases contains plaques, but displays few tangles and only moderate neuronal loss. The STG at post mortem may represent a brain region that is in the early stages of AD or alternately a region resistant to AD pathogenesis. We evaluated expression profiles and activity of endogenous anti-oxidants, oxidative damage and caspase activity in the STG of apolipoprotein ε4-matched human AD cases and controls. Total superoxide dismutase (SOD) activity was increased, whereas total glutathione peroxidase (GPX), catalase (CAT) and peroxiredoxin (Prx) activities, were decreased in the AD-STG, suggesting that hydrogen peroxide accumulates in this brain region. Transcripts of the transcription factor NFE2L2 and inducible HMOX1, were also increased in the AD-STG, and this corresponded to increased Nuclear factor erythroid 2-related factor (NRF-2) and total heme-oxygenase (HO) activity. The protein oxidation marker 4-hydroxynonenal (4-HNE), remained unchanged in the AD-STG. Similarly, caspase activity was unaltered, suggesting that subtle redox imbalances in early to moderate stages of AD do not impact STG viability.

Acute and Chronic Iron Overloading Differentially Modulates the Expression of Cellular Iron-homeostatic Molecules in Normal Rat Kidney.

Little is known about the renal responses to acute iron overloading. This study measured the renal tubular expression of transferrin receptor-1 (TfR1), cubilin/megalin receptors, hepcidin, ferroportin, and ferritin chains following subacute intoxication of 40 male Wistar rats with a single oral dose of ferrous iron (300 mg/kg). The animals were randomly subdivided into 4 equal subgroups at the time of necropsy (1, 2, 4, and 8 hr). The results were compared with the controls ( n=15) and with the chronic group ( n=15), which received iron for 4 weeks (75 mg/kg/day; 5 days/week). Although both toxicity models inhibited TfR1, they upregulated the cubilin/megalin receptors and hepcidin, and triggered iron deposition in tubular cells. The ferritin heavy-chain and ferroportin were downregulated in the 2-hr and 4-hr acute subgroups, whereas chronic toxicity promoted their expression, compared with controls. Moreover, the 4-hr and 8-hr subgroups had higher intracellular Fe+2 and marked cell apoptosis compared with the chronic group. In conclusion, the kidney appears to sustain iron reabsorption in both intoxication models. However, the cellular iron storage and exporter proteins were differentially expressed in both models, and their inhibition post-acute toxicity might contribute toward the intracellular accumulation of Fe+2, oxidative stress, and ferroptosis.

N-acetylcysteine transforms necrosis into apoptosis and affords tailored protection from cisplatin cytotoxicity.

Nephrotoxicity is the main limitation to the dosage and anticancer efficacy of cisplatin. Cisplatin produces tubular epithelial cell apoptosis and necrosis depending on the concentration of the drug. Protection from cisplatin nephrotoxicity must therefore tackle both cell death modes. For its ability to reduce cisplatin reactivity, in addition to its antioxidant effect, we tested and found that N-acetylcysteine (NAC) was most effective at inhibiting cisplatin cytotoxicity. NAC has no significant effect on cell death induced by either cycloheximide or Fas activation, indicating a rather selective action. Pt-DNA-binding experiments suggest that the differential effectiveness of NAC is due to its capacity to quench cisplatin reactivity inside the cell. NAC abolishes cisplatin-induced apoptosis, and transforms the necrosis induced by high concentrations of cisplatin into apoptosis. In fact, NAC allows the anti-apoptotic molecule Bcl-2 to reduce the cell death caused by pro-necrotic concentrations of cisplatin, to a significantly greater extent than in the absence of NAC. In rats, a dosage of NAC that significantly ameliorates cisplatin nephrotoxicity, has little effect on gentamicin nephrotoxicity. These characteristics provide NAC with a rationale as a potential nephroprotectant specifically tailored to and especially effective for therapeutic courses with platinated antineoplastics, which prompts to deepening into further preclinical knowledge, and to initiate clinical studies with NAC and mixed therapies composed of NAC and antiapoptotic drugs.

Withania somnifera modulates cancer cachexia associated inflammatory cytokines and cell death in leukaemic THP-1 cells and peripheral blood mononuclear cells (PBMC's).

BACKGROUND: Cancer and inflammation are associated with cachexia. Withania somnifera (W. somnifera) possesses antioxidant and anti-inflammatory potential. We investigated the potential of an aqueous extract of the root of W. somnifera (WRE) to modulate cytokines, antioxidants and apoptosis in leukaemic THP-1 cells and peripheral blood mononuclear cells (PBMC's). METHODS: Cytotoxcity of WRE was determined at 24 and 72 h (h). Oxidant scavenging activity of WRE was evaluated (2, 2-diphenyl-1 picrylhydrazyl assay). Glutathione (GSH) levels, caspase (- 8, - 9, - 3/7) activities and adenosine triphosphate (ATP) levels (Luminometry) were thereafter assayed. Tumour necrosis factor-α (TNF-α), interleukin (IL)-6, IL-1ß and IL-10 levels were also assessed using enzyme-linked immunosorbant assay. RESULTS: At 24 h, WRE (0.2-0.4 mg/ml) decreased PBMC viability between 20 and 25%, whereas it increased THP-1 viability between 15 and 23% (p < 0.001). At 72 h, WRE increased PBMC viability by 27-39% (0.05, 0.4 mg/ml WRE) whereas decreased THP-1 viability between 9 and 16% (0.05-0.4 mg/ml WRE) (p < 0.001). Oxidant scavenging activity was increased by WRE (0.05-0.4 mg/ml, p < 0.0001). PBMC TNF-α and IL-10 levels were decreased by 0.2-0.4 mg/ml WRE, whereas IL-1ß levels were increased by 0.05-0.4 mg/ml WRE (p < 0.0001). In THP-1 cells, WRE (0.05-0.4 mg/ml) decreased TNF-α, IL-1ß and IL-6 levels (p < 0.0001). At 24 h, GSH levels were decreased in PBMC's, whilst increased in THP-1 cells by 0.2-0.4 mg/ml WRE (p < 0.0001). At 72 h, WRE (0.1-0.4 mg/ml) decreased GSH levels in both cell lines (p < 0.0001). At 24 h, WRE (0.2-0.4 mg/ml) increased PBMC caspase (-8, -3/7) activities whereas WRE (0.05, 0.1, 0.4 mg/ml) increased THP-1 caspase (-9, -3/7) activities (p < 0.0001). At 72 h, PBMC caspase (-8, -9, -3/7) activities were increased at 0.05-0.1 mg/ml WRE (p < 0.0001). In THP-1 cells, caspase (-8, -9, -3/7) activities and ATP levels were increased by 0.1-0.2 mg/ml WRE, whereas decreased by 0.05 and 0.4 mg/ml WRE (72 h, p < 0.0001). CONCLUSION: In PBMC's and THP-1 cells, WRE proved to effectively modulate antioxidant activity, inflammatory cytokines and cell death. In THP-1 cells, WRE decreased pro-inflammatory cytokine levels, which may alleviate cancer cachexia and excessive leukaemic cell growth.

Design and application of a fluorogenic assay for monitoring inflammatory caspase activity.

Various fluorogenic assays exist for monitoring the activity of inflammatory caspases. However, there are no continuous assays that provide C-terminal substrate sequence specificity for inflammatory caspases. As a first step towards this, we have developed a continuous in vitro assay that relies on monitoring emission from tryptophan after cleavage of a quenching coumarin chromophore. The coumarin can be attached as an amino acid side chain or capping the C-terminus of the peptide. When the coumarin is a side chain, it allows for C-terminal and N-terminal sequence specificities to be explored. Using this assay, we obtained Michaelis-Menten kinetic data for four proof-of-principle peptides: WEHD-AMC (KM = 15 ± 2 µM), WEHD-MCA (KM = 93 ± 19 µM), WEHDG-MCA (KM = 21 ± 6 µM) and WEHDA-MCA (KM = 151 ± 37 µM), where AMC is 7-amino-4-methylcoumarin and MCA is ß-(7-methoxy-coumarin-4-yl)-Ala. The results indicate the viability of this new assay approach in the design of effective fluorogenic substrates for inflammatory caspases.

Rhein induces apoptosis and autophagy in human and rat glioma cells and mediates cell differentiation by ERK inhibition.

In this study, we investigated the anticancer potentials of Rhein, an anthraquinone derivative of most commonly used Chinese rhubarb on the rat F98 glioma cells. The experimental studies revealed that Rhein induced cell cycle arrest, caspase mediated apoptosis. It results in the formation of intracellular acidic vesicles in cytoplasm, leading to autophagy. Differentiation of viable cells towards elongation of matured astrocytes was proved by monitoring dramatic changes in morphological characteristics as well as identified from the elevation of glial fibrillary acidic protein (GFAP) expression. Rhein treatment did not alter the phosphorylated MAPKs activation including p-38, JNK and NF-κB, transcription unit whereas rhein significantly inhibited ERK1/2 activation in F98 glioma cells. PD98059, a specific inhibitor for ERK activation imitates rhein effects on morphology and expressions of GFAP but did not help to induce any apoptosis or autophagy. Collective data exhibited that potentials of rhein in anti-cancer property in ERK-independent apoptosis and autophagy in association with downregulated ERK-dependent differentiation process of glioma cell lines.

Synthesis of a HyCoSuL peptide substrate library to dissect protease substrate specificity.

Many biologically and chemically based approaches have been developed to design highly active and selective protease substrates and probes. It is, however, difficult to find substrate sequences that are truly selective for any given protease, as different proteases can demonstrate a great deal of overlap in substrate specificities. In some cases, better enzyme selectivity can be achieved using peptide libraries containing unnatural amino acids such as the hybrid combinatorial substrate library (HyCoSuL), which uses both natural and unnatural amino acids. HyCoSuL is a combinatorial library of tetrapeptides containing amino acid mixtures at the P4-P2 positions, a fixed amino acid at the P1 position, and an ACC (7-amino-4-carbamoylmethylcoumarin) fluorescent tag occupying the P1' position. Once the peptide is recognized and cleaved by a protease, the ACC is released and produces a readable fluorescence signal. Here, we describe the synthesis and screening of HyCoSuL for human caspases and legumain. We also discuss possible modifications and adaptations of this approach that make it a useful tool for developing highly active and selective reagents for a wide variety of proteolytic enzymes. The protocol can be divided into three major parts: (i) solid-phase synthesis of the fluorescence-labeled HyCoSuL, (ii) screening of protease P4-P2 preferences, and (iii) synthesis of the optimized activity probes equipped with an AOMK (acyloxymethyl ketone) reactive group and a biotin label for easy detection. Beginning with the library design, the entire protocol can be completed in 4-8 weeks (HyCoSuL synthesis: 3-5 weeks; HyCoSuL screening per enzyme: 4-8 d; and activity-based probe synthesis: 1-2 weeks).

Apoptosis, Expression of PAX3 and P53, and Caspase Signal in Fetuses with Neural Tube Defects.

BACKGROUND: Neural tube defects (NTDs) are among the most common and severe congenital malformations of the central nervous system. Animal studies have shown that apoptosis is involved in the development of NTDs. However, little evidence is available from human studies. We aim to examine the level of apoptosis and expression of apoptosis-regulating proteins of human terminated fetuses. METHODS: A total of 37 NTD cases and 21 controls from pregnancy terminations were recruited. Tissues of the central nervous system were obtained through autopsy. Apoptosis of neuroepithelial cells was examined by terminal deoxynucleotidyl transferase-mediated deoxyuridinetriphosphate nick end-labeling (TUNEL) assay. Expression of PAX3, p53, and caspase 3/8/9 in central nervous tissue was measured using Western blotting. RESULTS: More TUNEL-positive apoptosis cells were observed in the central nervous tissue of NTD cases than those of controls (p < 0.05). In spinal cord tissue, lower PAX3 expression, higher p53 expression, and increased levels of cleaved caspase 3(17kD) and cleaved caspase 8 (18kD) were found in anencephaly cases but not in spina bifida cases when compared with controls. In brain tissue, levels of PAX3 were significantly reduced in both encephalocele and spina bifida subtypes; the expression levels of cleaved caspase 3(17 kD) of encephalocele cases and cleaved caspase 8(47/45 kD) in spina bifida cases were higher than in controls; no difference was found in the expression of p53 or caspase 9 between NTDs and controls. CONCLUSION: These findings provide some evidence that excessive apoptosis in fetal central nervous tissues may be associated with the development of human NTDs. Birth Defects Research 109:1596-1604, 2017. © 2017 Wiley Periodicals, Inc.

Effects of selenium on the proliferation, apoptosis and testosterone production of sheep Leydig cells in vitro.

The objective of this study was to investigate the effects of selenium (Se) on in vitro proliferation, apoptosis and testosterone production of sheep Leydig cells and its underlying mechanism. Leydig cells were collected from 8-month-old sheep and divided into four treatment groups (0, 2.0, 4.0 and 8.0 µmol/L Se). After treatment with Se for 48 h, the MTT and flow cytometric assay were used to detect cell proliferation and apoptosis. Testosterone level in the culture medium was determined by ELISA. The mRNA expression and protein abundance of cell cycle, apoptosis and testosterone synthesis-related genes were detected using real-time PCR and western blot analysis. The results showed that the highest percentage of live and apoptotic cells was obtained in the 2.0 and 8.0 µmol/L group, respectively. In the Se treatment groups, the proliferation rate of Leydig cells and the expression of cell cycle-related genes were decreased with the increasing Se supplementation in the culture medium. The percentage of apoptotic cells was increased with the increasing Se level, which was consistent with the expression of pro-apoptosis genes. The highest GSH-Px activity and lowest ROS content were also observed in the 2.0 µmol/L group. Appropriate Se level (2.0 µmol/L) can significantly increase the expression of p-ERK1/2, StAR and 3ß-HSD, and improve the testosterone synthesis. Compared with the control group, PD0325901 could significantly inhibit the production of testosterone and the protein abundance of p-ERK1/2, StAR and 3ß-HSD. Se treatment can mitigate the inhibition effect of PD0325901 and the testosterone secretion between the 2.0 µmol/L and control group was not significantly different. These results demonstrate that Se can affect the proliferation and apoptosis of Leydig cells by regulating cellular oxidative stress and the expressions of cell cycle and apoptosis-related genes. Se can also enhance the testosterone production of Leydig cells by activating the ERK signaling pathway and the expression of its downstream genes (StAR and 3ß-HSD), which could be closely related to the regulating roles of Se in male fertility and spermatogenesis.

Effect of PUFAs Oral Administration on the Amount of Apoptotic Caspases Enzymes in Gastric Cancer Patients Undergoing Chemotherapy.

OBJECTIVE: Gastric cancer is the fourth most common cancer and the second cause of death in the world. According to the studies, the gastric cancer is relatively sensitive to chemotherapy. The aim of this study was to investigate the association of oral administer PUFAs with Caspase enzymes in patients with gastric cancer under chemotherapy. METHODS: This study was a Clinical Trial in which the target group consisted of the patients recognized with gastric cancer for the first time and cured under chemotherapy. Thirty-four patients were selected and categorized randomly into two groups. The case group included the patients taking PUFAs along with chemotherapeutic agent. In these patients, chemotherapy started with Cis-Platin plus PUFAs supplement in the scale of 3600 mg daily and in three courses. In control group, the individuals were under the same chemotherapy protocol without PUFAs. Biopsy samples from tumor were taken from the patients before and after chemotherapy. Levels of mRNA and protein expression of caspase 3, 8, 9 were measured in biopsy samples by Real-Time PCR and Frozen Section methods. The levels of apoptosis were determined using DNA-damage colorimetric assay. RESULTS: In the case group, caspase 3 showed a significant increase in both gene and protein expression levels after administration of PUFAs supplement in comparison with those of the control group (p=0.006 for gene, p=0.001 for protein). PUFAs induced caspase-9 gene expression level in these patients (p<0.0001). Caspase-9 protein level also revealed a marked elevation when PUFAs were administered along with chemotherapeutic agent (p<0.0001). DNA damage in gastric tissue from the patients under PUFAs treatment plus Cis-Platin was significantly higher than that of control group (p=0.003). PUFAs showed no significant changes in caspase-8 both at the gene and protein levels in the patients. CONCLUSION: According to the results of present study, it appears that oral administration of PUFAs can elevate the efficacy of chemotherapy agent in individuals' mitochondria-dependent apoptosis. As PUFAs enhances caspase-3 and 9 genes expression levels, which is an important induce the mitochondrial dependent apoptosis process. The study was registered in Iran clinical trials registry center under No. IRCT2014031016922N1.

Regulation of CED-3 caspase localization and activation by C. elegans nuclear-membrane protein NPP-14.

Caspases are cysteine proteases with critical roles in apoptosis. The Caenorhabditis elegans caspase CED-3 is activated by autocatalytic cleavage, a process enhanced by CED-4. Here we report that the CED-3 zymogen localizes to the perinuclear region in C. elegans germ cells and that CED-3 autocatalytic cleavage is held in check by C. elegans nuclei and activated by CED-4. The nuclear-pore protein NPP-14 interacts with the CED-3 zymogen prodomain, colocalizes with CED-3 in vivo and inhibits CED-3 autoactivation in vitro. Several missense mutations in the CED-3 prodomain result in stronger association with NPP-14 and decreased CED-3 activation by CED-4 in the presence of nuclei or NPP-14, thus leading to cell-death defects. Those same mutations enhance autocatalytic cleavage of CED-3 in vitro and increase apoptosis in vivo in the absence of npp-14. Our results reveal a critical role of nuclei and nuclear-membrane proteins in regulating the activation and localization of CED-3.