Role of Bcl-2 family proteins and caspases in the regulation of apoptosis

MicroRNA-15a/b are up-regulated in response to myocardial ischemia/reperfusion injury

Objective

Several studies have indicated that miR-15a, miR-15b and miR-16 may be the important regulators of apoptosis. Since attenuate apoptosis could protect myocardium and reduce infarction size, the present study was aimed to find out whether these miRNAs participate in regulating myocardial ischemia reperfusion (I/R) injury.

Methods

Apoptosis in mice hearts subjected to I/R was detected by TUNEL assay in vivo, while flow cytometry analysis followed by Annexin V/PI double stain in vitro was used to detect apoptosis in cultured cardiomyocytes which were subjected to hypoxia/reoxygenation (H/R). Taqman real-time quantitative PCR was used to confirm whether miR-15a/15b/16 were involved in the regulation of cardiac I/R and H/R.

Results

Compared to those of the controls, I/R or H/R induced apoptosis of cardiomyocytes was significantly increased both in vivo (24.4% ± 9.4% vs. 2.2% ± 1.9%, P < 0.01, n = 5) and in vitro (14.12% ± 0.92% vs. 2.22% ± 0.08%). The expression of miR-15a and miR-15b, but not miR-16, was increased in the mice I/R model, and the results were consistent in the H/R model.

Conclusions

Our data indicate miR-15 and miR-15b are up-regulated in response to cardiac I/R injury, therefore, down-regulation of miR-15a/b may be a promising strategy to reduce myocardial apoptosis induced by cardiac I/R injury.

Src kinases are important regulators of mitochondrial functions

Mitochondria produce the most part of the energy used by the cells. This energetic production occurs through the oxidative phosphorylation (OXPHOS) process. Mitochondrial functions such as OXPHOS need to be tightly regulated to respect the needs of cells. Phosphorylation of mitochondrial proteins now appears as a major regulation pathway of mitochondrial functions. Several kinases and phosphatases are specifically targeted to mitochondria where they modulate mitochondrial functions. However, we still poorly understand the extent of tyrosine phosphorylation events on mitochondrial metabolism. Among the tyrosine-kinases observed in mitochondria, Src kinases emerge as key players. In the past years, several mitochondrial proteins were shown to be substrates of Src kinases. Notably, these kinases can impact greatly OXPHOS and apoptosis. Important regulators of Src kinases activity are also observed in mitochondria. The aim of this review is to summarize the recent findings on how overall mitochondrial tyrosine phosphorylation events and more specifically Src kinases can influence mitochondrial functions. The different mechanisms of Src kinases regulation and translocation into mitochondria will be also discussed. This article is part of a Directed Issue entitled: Bioenergetic dysfunction, adaptation and therapy.

Investigation of the chemopreventive potential of neem leaf subfractions in the hamster buccal pouch model and phytochemical characterization

Chemoprevention by medicinal plants has evolved as a practical strategy to control the incidence of cancer. Azadirachta indica (neem) containing various bioactive components is a promising candidate for chemoprevention. The present study was undertaken to evaluate the chemopreventive efficacy of the bioactive subfractions ethyl acetate chloroform insoluble fraction (ECIF) and the methanol ethyl acetate insoluble fraction (MEIF) following activity-guided fractionation of neem leaf extract. Analysis of the mechanism of chemoprevention revealed multitargeted mode of action that involved modulation of xenobiotic-metabolizing enzymes, inhibition of cell proliferation, induction of mitochondrial apoptosis, and abrogation of NF-κB signaling. HP-TLC, GC-MS and LC-MS analyses indicated the presence of several polar phytochemical entities in the neem leaf subfractions that might be responsible for their potent chemopreventive efficacy.

D(-)lentiginosine-induced apoptosis involves the intrinsic pathway and is p53-independent

We have recently found that 𝒟(−)lentiginosine, a synthetic iminosugar exerting glucosidase inhibitory activity, but not its natural enantiomer lentiginosine, is endowed with an unexpected, pro-apoptotic activity. Here, we investigated mechanisms involved in apoptosis induced by 𝒟−)lentiginosine in MOLT-3, HT-29 and SH-SY5Y tumour cell lines. The results showed that 𝒟−)lentiginosine increased caspase 9 expression at 18 h in all the cell lines from 1.5–3.1 folds. Cytochrome c in the cytoplasm was found to be increased from 2.3–2.6 folds in treated cells with respect to control cells. These effects were accompanied by a remarkable collapse of the mitochondrial membrane potential and by the downregulation of anti-apoptotic genes, as well as the upregulation of pro-apoptotic genes of the Bcl-2 family. U937Bcl-2 transfectants, highly expressing Bcl-2, were reluctant to undergo apoptosis even following treatment with 500 μM 𝒟−)lentiginosine, whereas apoptosis by 𝒟−)lentiginosine was induced also in U937 cells, naturally deficient in P53. Thus, our study establishes that the enantiomer of a natural iminosugar is endowed with a possible anti-tumorigenic effect that might be ascribed not only to their capacity to inhibit glycosidases but also to other unknown mechanisms. These data encourage further investigation on similar compounds to make them an interesting platform for the generation of new anticancer drugs.

Mitigation of H(2)O(2)-Induced Mitochondrial-Mediated Apoptosis in NG108-15 Cells by Novel Mesuagenin C from Mesua kunstleri (King) Kosterm

This study was aimed to isolate and evaluate neuroprotective compounds from the hexane extract of the bark of Mesua kunstleri (Clusiaceae) on H(2)O(2)-induced apoptosis in NG108-15 cells. Five 4-phenylcoumarins were isolated by using various chromatographic techniques via neuroprotective activity-guided fractionation and isolation from the active hexane extract. The chemical structures of the isolated compounds were confirmed by NMR spectroscopic data interpretation and comparison with literature values. Cell viability data demonstrated that mesuagenin C 3 significantly increased cell viability. Hoechst 33342/PI staining illustrated mesuagenin C 3 was able to abate the nuclear shrinkage, chromatin condensation and formation of apoptotic bodies. Pretreatment with mesuagenin C 3 reduced total annexin V positive cells and increased the level of intracellular glutathione (GSH). Mesuagenin C 3 attenuated membrane potential (Δψm), reduced Bax/Bcl-2 ratio and inactivated of caspase-3/7 and -9. These results indicated that mesuagenin C 3 could protect NG108-15 cells against H(2)O(2)-induced apoptosis by increasing intracellular GSH level, aggrandizing Δψm, and modulating apoptotic signalling pathway through Bcl-2 family and caspase-3/7 and -9. These findings confirmed the involvement of intrinsic apoptotic pathway in H(2)O(2)-induced apoptosis and suggested that mesuagenin C 3 may have potential therapeutic properties for neurodegenerative diseases.

Use of fluorochrome-labeled inhibitors of caspases to detect neuronal apoptosis in the whole-mounted lamprey brain after spinal cord injury

Apoptosis is a major feature in neural development and important in traumatic diseases. The presence of active caspases is a widely accepted marker of apoptosis. We report here the development of a method to study neuronal apoptotic death in whole-mounted brain preparations using fluorochrome-labeled inhibitors of caspases (FLICA). As a model we used axotomy-induced retrograde neuronal death in the CNS of larval sea lampreys. Once inside the cell, the FLICA reagents bind covalently to active caspases causing apoptotic cells to fluoresce, whereas nonapoptotic cells remain unstained. The fluorescent probe, the poly caspase inhibitor FAM-VAD-FMK, was applied to whole-mounted brain preparations of larval sea lampreys 2 weeks after a complete spinal cord (SC) transection. Specific labeling occurred only in identifiable spinal-projecting neurons of the brainstem previously shown to undergo apoptotic neuronal death at later times after SC transection. These neurons also exhibited intense labeling 2 weeks after a complete SC transection when a specific caspase-8 inhibitor (FAM-LETD-FMK) served as the probe. In this study we show that FLICA reagents can be used to detect specific activated caspases in identified neurons of the whole-mounted lamprey brain. Our results suggest that axotomy may cause neuronal apoptosis by activation of the extrinsic apoptotic pathway.

Protective effect of plaunotol against doxorubicin-induced renal cell death

In searching for a safe and effective compound to be used as a chemoprotective agent to prevent toxicity of the anthracyclin doxorubicin to renal cells, the present study demonstrated that plaunotol, a purified acyclic diterpene from Croton stellatopilosus Ohba, showed potential protection against doxorubicin-induced cell death in human proximal tubule cells. Treatment of renal cells with doxorubicin resulted in a significant decrease in viability of the cells, and we next proved that such toxicity was mainly due to apoptotic cell death. Pretreatment of the cells with plaunotol for at least 9 h prior to doxorubicin exposure improved the cells' survival. Plaunotol was shown to up-regulate the anti-apoptotic myeloid cell leukemia-1 (Mcl-1) level whereas it had no effect on the Bcl-2 level. The reduction in Mcl-1 after doxorubicin treatment was shown to be closely associated with the toxic action of the drug, and the increase in Mcl-1 induced by plaunotol pretreatment was able to prevent cell death induced by doxorubicin. Furthermore, the protective effect of plaunotol was evaluated in human lung and melanoma cells. Results indicated that plaunotol had no significantly protective effect in human lung carcinoma cells, whereas it sensitized melanoma cells to drug-induced cell death.

ASK1 promotes apoptosis of normal and malignant plasma cells

Although the overproduction of immunoglobulins by short-lived plasma cells accompanying an immune response links with their apoptosis, how long-lived plasma cells adapt to ensure their longevity in this context is obscure. Here, we show that apoptosis signal-regulating kinase 1 (ASK1) contributes to apoptosis of plasma cells because ASK1 activity was induced during differentiation of short-lived plasma cells, and, when produced by ASK1-deficient mice, these cells survived better than those of control mice. Moreover, antigen-specific long-lived plasma cells generated by immunization accumulated in ASK1-deficient mice, suggesting ASK1 also plays a negative role in survival of long-lived plasma cells. In malignant plasma cells, ASK1 transcription was directly suppressed by B lymphocyte-induced maturation protein-1 (Blimp-1). The expression of ASK1 and Blimp-1 showed an inverse correlation between normal human mature B cells and bone marrow plasma cells from patients with multiple myeloma (MM). Suppression of ASK1 is crucial for cell survival because its enforced expression in MM cells caused apoptosis in vitro and lowered MM load in a xenograft animal model; furthermore, alteration of ASK1 activity affected MM cell survival. Our findings indicate a novel mechanism underlying the regulation of survival in normal and malignant plasma cells by ASK1.

Depletion of SLC4A11 causes cell death by apoptosis in an immortalized human corneal endothelial cell line

PURPOSE

To investigate the effects of SLC4A11 gene depletion in human corneal endothelial cells.

METHODS

To achieve stable downregulation of SLC4A11 gene expression in immortalized human corneal endothelial cells (HCECs), short-hairpin RNA (shRNA) targeted against SLC4A11 was used. Cell growth and viability were determined using the real-time cell analyzer and trypan blue staining respectively. Apoptosis was investigated by Annexin V and TUNEL assays. Alterations in apoptotic gene expression following SLC4A11 silencing were determined using the RT(2)Profiler PCR array for human apoptosis while activation of the apoptotic pathway was ascertained by western analysis.

RESULTS

SLC4A11 silencing in HCECs could be achieved by stable expression of shRNA targeted against SLC4A11. SLC4A11 knockdown suppressed HCEC growth and reduced HCEC viability compared to the control. This reduction in cell growth is associated with increased apoptosis in SLC4A11-silenced cells.

CONCLUSIONS

Our data suggest that the reduction of cell number with time in SLC4A11-depleted HCECs is due to an increase in cell death by apoptosis. This suggests that SLC4A11 is necessary for cell survival and may explain the pathologic corneal endothelial cell loss in endotheliopathies due to SLC4A11 mutations.

The protective effects of carnosine in alcohol-induced hepatic injury in rats

Consumption of alcohol leads to oxidative stress in liver by inducing lipid peroxidation. The aim of this study was to investigate the effects of carnosine (CAR) in alcohol-induced liver injury by biochemical and histomorphological evaluations. The rats were divided into four groups, namely, control group, alcohol (AL) group, CAR group and AL + CAR group. Three doses of ethanol (5 g/kg, 25% (v/v) in distilled water) were given by nasogastric catheter for twice-a-day. CAR (100 mg/kg) was given 1 h before the administration of ethanol using the same method. Levels of alanine aminotransferase, aspartate aminotransferase, myeloperoxidase and malondialdehyde were significantly increased in the AL group compared with control, CAR and AL + CAR groups. Glutathione level was significantly decreased in the AL group, while it was increased in the AL + CAR group. Immunoreactivity of caspase-3 and bax increased in the hepatocytes of AL group when compared with control and AL + CAR groups. Expression of bcl-2 was decreased in AL group than AL + CAR group. Under electron microscopy, dense mitochondria, accumulation of lipid, sinusoidal dilatation, vacuolization and decrease in the number of microvilli were observed in AL group, while these findings were markedly less in the AL + CAR group. In conclusion, pretreatment of CAR is effective for recovering biochemical alterations and morphologic damage in the liver of rats treated with ethanol.

Pretubulysin: from hypothetical biosynthetic intermediate to potential lead in tumor therapy

Pretubulysin is a natural product that is found in strains of myxobacteria in only minute amounts. It represents the first enzyme-free intermediate in the biosynthesis of tubulysins and undergoes post-assembly acylation and oxidation reactions. Pretubulysin inhibits the growth of cultured mammalian cells, as do tubulysins, which are already in advanced preclinical development as anticancer and antiangiogenic agents. The mechanism of action of this highly potent compound class involves the depolymerization of microtubules, thereby inducing mitotic arrest. Supply issues with naturally occurring derivatives can now be circumvented by the total synthesis of pretubulysin, which, in contrast to tubulysin, is synthetically accessible in gram-scale quantities. We show that the simplified precursor is nearly equally potent to the parent compound. Pretubulysin induces apoptosis and inhibits cancer cell migration and tubulin assembly in vitro. Consequently, pretubulysin appears to be an ideal candidate for future development in preclinical trials and is a very promising early lead structure in cancer therapy.

Standardized flavonoid-rich fraction of Artemisia princeps Pampanini cv. Sajabal induces apoptosis via mitochondrial pathway in human cervical cancer HeLa cells

ETHNOPHARMACOLOGICAL RELEVANCE

Artemisia princeps Pampanini is widely used in Eastern traditional medicine for the treatment of circulatory disorders, such as, dysmenorrhea, hematuria, hemorrhoids, and inflammation, and is also used to treat chronic conditions, such as, cancers, ulcers, and digestive disorders.

AIM OF THE STUDY

The purpose of this study is to investigate the effect of a standardized flavonoid-rich fraction of Artemisia princeps Pampanini cv. Sajabal (FRAP) on the induction of apoptosis and the molecular mechanism involved in human cervical cancer HeLa cells.

MATERIALS AND METHODS

Human cervical cancer HeLa cells were treated with FRAP and apoptosis was detected by cell morphologic observation, annexin-V-PI staning and western blot analysis on the expression of protein associated with cell death.

RESULTS

FRAP led to the cleavages of caspase-3, -8, and -9 and the cleavage of poly (ADP-ribose) polymerase (PARP) in HeLa cells. Caspase-3 inhibitor (z-DEVD-fmk), caspase-8 inhibitor (z-IETD-fmk), caspase-9 inhibitor (z-LEHD), and broad caspase inhibitor (z-VAD-fmk) significantly suppressed the FRAP-induced accumulation of annexin V positive cells. Furthermore, it was found that FRAP caused a loss of mitochondrial membrane potential (MMP) and the release of cytochrome c to the cytosol. Furthermore, the overexpression of Bcl-xL significantly prevented FRAP-induced apoptosis, MMP changes, and the activations of caspase-3, -8, and -9. Interestingly, pretreatment with caspase-8 inhibitor significantly reduced the FRAP-induced activation of caspase-3 but not that of caspase-9, whereas the caspase-3 inhibitor, z-DEVD-fmk, markedly attenuated the FRAP-induced activation of caspase-8. In BALB/c(nu/nu) mice bearing a HeLa xenograft, FRAP dosed at 25 or 50mg/kg significantly inhibited tumor growth.

CONCLUSION

Our results indicate caspase-mediated activation of the mitochondrial death pathway plays a critical role in the FRAP-induced apoptosis of HeLa cells and that FRAP inhibits the in vivo tumor growth of HeLa xenograft mice.

Inhibition of fatty-acid synthase suppresses P-AKT and induces apoptosis in bladder cancer

OBJECTIVE

To investigate the role of fatty acid synthase (FASN) in bladder transitional cell carcinoma (BTCC).

METHODS

FASN expression was investigated in non-muscle-invasive BTCC tissue specimens by immunohistochemistry and BTCC cell lines by Western blot. After treatment with FASN-siRNA or FASN inhibitor cerulenin (Cer), the proliferation and apoptosis of BTCC cell lines 5637 and 253 J were determined by cell counting Kit-8 (CCK8) assay and flow cytometry respectively. The expression of p-AKT, cyclin D1 (CCND1), and apoptosis-related proteins were detected by Western blot.

RESULTS

High levels of FASN expression were observed in 59% (32/54) of non-muscle-invasive BTCC tissue specimens, and FASN expression was associated with histologic grade (P < .05) and recurrence (P < .05). FASN expression was high in 6 BTCC cell lines. FASN inhibitor Cer and FASN-siRNA produced the increased apoptosis and decreased proliferation of bladder cancer cells, and caused inactivity of AKT and downregulation of CCND1. Furthermore, treatment of BTCC cell lines with Cer resulted in apoptosis via the caspase-dependent pathway involving inactivation of antiapoptotic bcl-2 protein.

CONCLUSION

Our data suggest that FASN plays an important role in BTCC development. Targeting FASN may be a new therapeutic strategy for BTCC.

Molecular Mechanisms of Cytotoxicity and Apoptosis Induced by Inorganic Fluoride

Fluoride (F) is ubiquitous natural substance and widespread industrial pollutant. Although low fluoride concentrations are beneficial for normal tooth and bone development, acute or chronic exposure to high fluoride doses results in adverse health effects. The molecular mechanisms underlying fluoride toxicity are different by nature. Fluoride is able to stimulate G-proteins with subsequent activation of downstream signal transduction pathways such as PKA-, PKC-, PI3-kinase-, Ca2+-, and MAPK-dependent systems. G-protein-independent routes include tyrosine phosphorylation and protein phosphatase inhibition. Along with other toxic effects, fluoride was shown to induce oxidative stress leading to excessive generation of ROS, lipid peroxidation, decrease in the GSH/GSSH ratio, and alterations in activities of antioxidant enzymes, as well as to inhibit glycolysis thus causing the depletion of cellular ATP and disturbances in cellular metabolism. Fluoride triggers the disruption of mitochondria outer membrane and release of cytochrome c into cytosol, what activates caspases-9 and -3 (intrinsic) apoptotic pathway. Extrinsic (death receptor) Fas/FasL-caspase-8 and -3 pathway was also described to be implicated in fluoride-induced apoptosis. Fluoride decreases the ratio of antiapoptotic/proapoptotic Bcl-2 family proteins and upregulates the expression of p53 protein. Finally, fluoride changes the expression profile of apoptosis-related genes and causes endoplasmic reticulum stress leading to inhibition of protein synthesis.

The Apaf-1-binding protein Aven is cleaved by Cathepsin D to unleash its anti-apoptotic potential

The anti-apoptotic molecule Aven was originally identified in a yeast two-hybrid screen for Bcl-x(L)-interacting proteins and has also been found to bind Apaf-1, thereby interfering with Apaf-1 self-association during apoptosome assembly. Aven is expressed in a wide variety of adult tissues and cell lines, and there is increasing evidence that its overexpression correlates with tumorigenesis, particularly in acute leukemias. The mechanism by which the anti-apoptotic activity of Aven is regulated remains poorly understood. Here we shed light on this issue by demonstrating that proteolytic removal of an inhibitory N-terminal Aven domain is necessary to activate the anti-apoptotic potential of the molecule. Furthermore, we identify Cathepsin D (CathD) as the protease responsible for Aven cleavage. On the basis of our results, we propose a model of Aven activation by which its N-terminal inhibitory domain is removed by CathD-mediated proteolysis, thereby unleashing its cytoprotective function.

MicroRNAs in Alzheimer's disease

Alzheimer's disease (AD) is a complex neurodegenerative disorder and is the most common form of dementia in the elderly. Accumulating evidence in AD research suggests that alterations in the microRNA (miRNA) network could contribute to risk for the disease. miRNAs are conserved small non-coding RNAs that control gene expression at the posttranscriptional level and are essential for neuronal function and survival. The results from recent profiling experiments in humans suggest that a number of specific miRNAs are misregulated in disease conditions, several of which have been implicated in the regulation of key genes involved in AD, including APP, BACE1 and MAPT. Moreover, rare disease-specific polymorphisms have been identified in known and putative miRNA target sites located within the 3'untranslated regions (3'UTRs) of APP and BACE1 genes. Here, we review current findings regarding miRNA research in humans and various cellular and animal models to provide a strong basis for future research aimed at understanding the potential contribution of miRNAs to AD pathophysiology.

Generation of reactive oxygen species mediates butein-induced apoptosis in neuroblastoma cells

Flavonoids exhibit chemopreventive and chemotherapeutic effects. Butein, a bioactive flavonoid isolated from numerous native plants, has been shown to induce apoptosis in human cancer cells. In the current study, the molecular mechanisms of butein action on cell proliferation and apoptosis of neuroblastoma cells were evaluated. Treatment with butein decreased the viability of Neuro-2A neuroblastoma cells in a dose- and time-dependent manner. The dose-dependent nature of butein-induced apoptosis was characterized by an increase in the sub-G1 phase population. Treatment with butein significantly increased intracellular reactive oxygen species (ROS)levels and reduced the Bcl-2/Bax ratio, triggering the cleavage of pro-caspase 3 and poly-(ADP-ribose) polymerase (PARP). Pre-treatment with the antioxidant agent, N-acetyl cysteine (NAC), blocks butein-induced ROS generation and cell death. NAC also recovers butein-induced apoptosis-related protein alteration. In conclusion, butein-triggered neuroblastoma cells undergo apoptosis via generation of ROS, alteration of the Bcl-2/Bax ratio, and cleavage of pro-caspase 3 and PARP. Our results suggest that butein may serve as a potential therapeutic agent for the treatment of neuroblastoma.

Stem-like cells and therapy resistance in squamous cell carcinomas

Cancer stem cells (CSCs) within squamous cell carcinomas (SCCs) are hypothesized to contribute to chemotherapy and radiation resistance and represent potentially useful pharmacologic targets. Hallmarks of the stem cell phenotype that may contribute to therapy resistance of CSCs include quiescence, evasion of apoptosis, resistance to DNA damage, and expression of drug transporter pumps. A variety of CSC populations within SCCs of the head and neck and esophagus have been defined tentatively, based on diverse surface markers and functional assays. Stem-like self-renewal and differentiation capacities of these SCC subpopulations are supported by sphere formation and clonogenicity assays in vitro as well as limiting dilution studies in xenograft models. Early evidence supports a role for SCC CSCs in intrinsic therapy resistance, while detailed mechanisms by which these subpopulations evade treatment remain to be defined. Development of novel SCC therapies will be aided by pursuing such mechanisms as well as refining current definitions for CSCs and clarifying their relevance to hierarchical versus dynamic models of stemness.

miR-181a sensitizes resistant leukaemia HL-60/Ara-C cells to Ara-C by inducing apoptosis

BACKGROUND

Ara-C is one of the most commonly used drugs in the treatment of AML. However, the development of drug resistance always prevented its further use. It has been shown that miR-181a is associated with the clinical outcome of AML patients. Here, we investigated the possible role of miR-181a in AML Ara-C resistance.

METHODS

miR-181a expression was measured by real-time PCR. Cell viability was detected by MTT assay. Protein expressions were measured by western blotting. Caspase activity was examined by fluorescence assay.

RESULTS

We found that miR-181a expression was downregulated in the Ara-C-resistant cell line HL-60/Ara-C compared with its parental cell line HL-60. Overexpression of miR-181a in HL-60/Ara-C cells sensitized the cells to Ara-C treatment. Furthermore, Bcl-2 was confirmed as a direct miR-181a target by immunoblot analysis and reporter gene assays. Knockdown of Bcl-2 mimicked the effect of enforced miR-181a expression by reducing cell viability. In addition, the apoptosis pathway was activated by cytochrome C release and caspase 9/caspase 3 activation after miR-181a overexpression.

CONCLUSIONS

This study for the first time demonstrated that downregulation of miR-181a and upregulation of Bcl-2 in leukaemia cells confer resistance to Ara-C-based therapy. These results suggest that restoration of miR-181a expression might provide a promising therapeutic in drug resistance of leukaemia.

Prenatal stress induces long-term effects in cell turnover in the hippocampus-hypothalamus-pituitary axis in adult male rats

Subchronic gestational stress leads to permanent modifications in the hippocampus-hypothalamus-pituitary-adrenal axis of offspring probably due to the increase in circulating glucocorticoids known to affect prenatal programming. The aim of this study was to investigate whether cell turnover is affected in the hippocampus-hypothalamus-pituitary axis by subchronic prenatal stress and the intracellular mechanisms involved. Restraint stress was performed in pregnant rats during the last week of gestation (45 minutes; 3 times/day). Only male offspring were used for this study and were sacrificed at 6 months of age. In prenatally stressed adults a decrease in markers of cell death and proliferation was observed in the hippocampus, hypothalamus and pituitary. This was associated with an increase in insulin-like growth factor-I mRNA levels, phosphorylation of CREB and calpastatin levels and inhibition of calpain -2 and caspase -8 activation. Levels of the anti-apoptotic protein Bcl-2 were increased and levels of the pro-apoptotic factor p53 were reduced. In conclusion, prenatal restraint stress induces a long-term decrease in cell turnover in the hippocampus-hypothalamus-pituitary axis that might be at least partly mediated by an autocrine-paracrine IGF-I effect. These changes could condition the response of this axis to future physiological and pathophysiological situations.

Overlapping, additive and counterregulatory effects of type II and I interferons on myeloid dendritic cell functions

Dendritic cells (DCs) are central player in immunity by bridging the innate and adaptive arms of the immune system (IS). Interferons (IFNs) are one of the most important factors that regulate both innate and adaptive immunity too. Thus, the understanding of how type II and I IFNs modulate the immune-regulatory properties of DCs is a central issue in immunology. In this paper, we will address this point in the light of the most recent literature, also highlighting the controversial data reported in the field. According to the wide literature available, type II as well as type I IFNs appear, at the same time, to collaborate, to induce additive effects or overlapping functions, as well as to counterregulate each one's effects on DC biology and, in general, the immune response. The knowledge of these effects has important therapeutic implications in the treatment of infectious/autoimmune diseases and cancer and indicates strategies for using IFNs as vaccine adjuvants and in DC-based immune therapeutic approaches.

Antcin B and its ester derivative from Antrodia camphorata induce apoptosis in hepatocellular carcinoma cells involves enhancing oxidative stress coincident with activation of intrinsic and extrinsic apoptotic pathway

The triterpenoids methylantcinate B (MAB) and antcin B (AB), isolated from the medicinal mushroom Antrodia camphorata , have been identified as strong cytotoxic agents against various type of cancer cells; however, the mechanisms of MAB- and AB-induced cytotoxicity have not been adequately explored. This study investigated the roles of caspase cascades, reactive oxygen species (ROS), DNA damage, mitochondrial disruption, and Bax and Bcl-2 proteins in MAB- and AB-induced apoptosis of hepatocellular carcinoma (HCC) HepG2 cells. Here, we showed that MAB and AB induced apoptosis in HepG2 cells, as characterized by increased DNA fragmentation, cleavage of PARP, sub-G1 population, chromatin condensation, loss of mitochondrial membrane potential, and release of cytochrome c. Increasing the levels of caspase-2, -3, -8, and -9 activities was involved in MAB- and AB-induced apoptosis, and they could be attenuated by inhibitors of specific caspases, indicating that MAB and AB triggered the caspase-dependent apoptotic pathway. Additionally, the enhanced apoptotic effect correlates with high expression of Fas, Fas ligand, as well as Bax and decreased protein levels of Bcl-(XL) and Bcl-2, suggesting that both the extrinsic and intrinsic apoptosis pathways were involved in the apoptotic processes. Incubation of HepG2 cells with antioxidant enzymes superoxide dismutase and catalase and antioxidants N-acetylcysteine and ascorbic acid attenuated the ROS generation and apoptosis induced by MAB and AB, which indicate that ROS plays a pivotal role in cell death. NADPH oxidase activation was observed in MAB- and AB-stimulated HepG2 cells; however, inhibition of such activation by diphenylamine significantly blocked MAB- and AB-induced ROS production and increased cell viability. Taken together, our results provide the first evidence that triterpenoids MAB and AB induced a NADPH oxidase-provoked oxidative stress and extrinsic and intrinsic apoptosis as a critical mechanism of cause cell death in HCC cells.

A melanoma molecular disease model

While advanced melanoma remains one of the most challenging cancers, recent developments in our understanding of the molecular drivers of this disease have uncovered exciting opportunities to guide personalized therapeutic decisions. Genetic analyses of melanoma have uncovered several key molecular pathways that are involved in disease onset and progression, as well as prognosis. These advances now make it possible to create a “Molecular Disease Model” (MDM) for melanoma that classifies individual tumors into molecular subtypes (in contrast to traditional histological subtypes), with proposed treatment guidelines for each subtype including specific assays, drugs, and clinical trials. This paper describes such a Melanoma Molecular Disease Model reflecting the latest scientific, clinical, and technological advances.