Live and let die: regulatory mechanisms in Fas-mediated apoptosis

Role of non-coding RNAs as new therapeutic targets in regulating the EMT and apoptosis in metastatic gastric and colorectal cancers

Colorectal cancer (CRC) and gastric cancer (GC), are the two most common cancers of the gastrointestinal tract, and are serious health concerns worldwide. The discovery of more effective biomarkers for early diagnosis, and improved patient prognosis is important. Non-coding RNAs (ncRNAs), including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), can regulate cellular processes such as apoptosis and the epithelial-mesenchymal transition (EMT) leading to progression and resistance of GC and CRC tumors. Moreover these pathways (apoptosis and EMT) may serve as therapeutic targets, to prevent metastasis, and to overcome drug resistance. A subgroup of ncRNAs is common to both GC and CRC tumors, suggesting that they might be used as biomarkers or therapeutic targets. In this review, we highlight some ncRNAs that can regulate EMT and apoptosis as two opposite mechanisms in cancer progression and metastasis in GC and CRC. A better understanding of the biological role of ncRNAs could open up new avenues for the development of personalized treatment plans for GC and CRC patients.

Effects of High-Intensity Interval Training on Melatonin Function and Cellular Lymphocyte Apoptosis in Sedentary Middle-Aged Men

Background: Physical performance increased by controlled interventions of high-intensity intermittent training (HIIT); however, little is known about their influence as anti-aging and antioxidant effects, or their role in mitochondrial biogenesis. Purpose: This study aimed to determine the effects of HIIT for 12 weeks on melatonin function, lymphocyte cell apoptosis, oxidative stress on aging, and physical performance. Methods: Eighty healthy male subjects aged 18-65 years randomly participated in a HIIT-exercise training program for 12 weeks. Anthropometric analysis, cardiovascular fitness, total antioxidant capacity (TAC), lymphocyte count and apoptosis, and serum melatonin and cytochrome c oxidase (COX), were estimated for all subjects before and after HIIT-exercise training. HIIT training was performed in subjects for 12 weeks. Results: Data analysis showed a significant increase in the expression levels of the melatonin hormone (11.2 ± 2.3, p < 0.001), TAC (48.7 ± 7.1, p < 0.002), COX (3.7 ± 0.75, p < 0.001), and a higher percentage of lymphocyte apoptosis (5.2 ± 0.31, p < 0.003). In addition, there was an improvement in fitness scores (W; 196.5 ± 4.6, VO₂max; 58.9 ± 2.5, p < 0.001), adiposity markers (p < 0.001); BMI, WHtR, and glycemic control parameters (p < 0.01); FG, HbA1c (%), FI, and serum C-peptide were significantly improved following HIIT intervention. Both melatonin and lymphocyte apoptosis significantly correlated with the studied parameters, especially TAC and COX. Furthermore, the correlation of lymphocyte apoptosis with longer exercise duration was significantly associated with increased serum melatonin following exercise training. This association supports the mechanistic role of melatonin in promoting lymphocyte apoptosis either via the extrinsic mediator pathway or via inhibition of lymphocyte division in the thymus and lymph nodes. Additionally, the correlation between melatonin, lymphocyte apoptosis, TAC, and COX activities significantly supports their role in enhancing physical performance. Conclusions: The main findings of this study were that HIIT exercise training for 12 weeks significantly improved adiposity markers, glycemic control parameters, and physical performance of sedentary older adult men. In addition, melatonin secretion, % of lymphocyte apoptosis, COX activities, and TAC as biological aging markers were significantly increased following HIIT exercise training interventions for 12 weeks. The use of HIIT exercise was effective in improving biological aging, which is adequate for supporting chronological age, especially regarding aging problems. However, subsequent studies are required with long-term follow-up to consider HIIT as a modulator for several cardiometabolic health problems in older individuals with obesity.

Investigation of the effects of atorvastatin and Lactobacillus acidophilus on some hormones and oxidative stress in experimental hypercholesterolemia

AIM

The investigation of serum leptin, ghrelin, insulin, seratonin hormones, NO, total oxidant/antioxidant status and brain cannaboid 1 receptor protein and apoptotic cell levels in atorvastatin and Lactobacillus acidophilus administrated experimental hypercholesterolemia was aimed in the project.

METHODS

In the study, 5 experimental groups were formed. Group 1 was fed with standard rat chow, and Group 2 was fed with 2% cholesterol added standard rat chow for 8 weeks. Group 3 was fed with 2% cholesterol feed and received atorvastatin (20 mg/kg/day) for the last 4 weeks. Group 4 was given L. acidophilus (2 ×10⁸ cfu/kg/day). Group 5 was given atorvastatin and L. acidophilus probiotic in the last 4 weeks of the experiment period. After the experimental period, blood samples were taken from each rat. Rats were sacrificed and brain tissues were taken for analyzes. In sera samples, leptin, ghrelin, insulin, serotonin hormones and NO levels were measured with ELISA. In brain samples, cannabinoid 1 receptor proteins and apoptosis levels were measured by ELISA. Total oxidant and antioxidant levels were investigated with using Rel Assay Kits.

RESULTS

The addition of cholesterol to feeds increased the levels of serum cholesterol, insulin and leptin levels; on the other hand, reduced the levels of serotonin and ghrelin. In hypercholesterolemia, total oxidant and NO levels were increased, and total antioxidant levels were decreased.

CONCLUSION

The results showed that administrations of L. acidophilus and atorvastatin might be recommended for treatment of hypercholesterolemia.

Boosting Productivity for Advanced Biomanufacturing by Re-Using Viable Cells

Monoclonal antibodies (mAb) have gained enormous therapeutic application during the last decade as highly efficient and flexible tools for the treatment of various diseases. Despite this success, there remain opportunities to drive down the manufacturing costs of antibody-based therapies through cost efficiency measures. To reduce production costs, novel process intensification methods based on state-of-the-art fed-batch and perfusion have been implemented during the last few years. Building on process intensification, we demonstrate the feasibility and benefits of a novel, innovative hybrid process that combines the robustness of a fed-batch operation with the benefits of a complete media exchange enabled through a fluidized bed centrifuge (FBC). In an initial small-scale FBC-mimic screening, we investigated multiple process parameters, resulting in increased cell proliferation and an elongated viability profile. Consecutively, the most productive process scenario was transferred to the 5-L scale, further optimized and compared to a standard fed-batch process. Our data show that the novel hybrid process enables significantly higher peak cell densities (163%) and an impressive increase in mAb amount of approximately 254% while utilizing the same reactor size and process duration of the standard fed-batch operation. Furthermore, our data show comparable critical quality attributes (CQAs) between the processes and reveal scale-up possibilities and no need for extensive additional process monitoring. Therefore, this novel process intensification strategy yields strong potential for transfer into future industrial manufacturing processes.

The mechanism of immune related signal pathway Egr2-FasL-Fas in transcription regulation and methylated modification of Paralichthys olivaceus under acute hypoxia stress

Apoptosis genes Egr2, Fas and FasL are related to immune responses. However, the mechanism of these genes inducing apoptosis in fish are still not very clear. An acute hypoxia treatment (1.73 ± 0.06 mg/L) for 24 h was carried out on Japanese flounder (Paralichthys olivaceus). The increasingly dense apoptotic signals at 3 h, 6 h, 12 h by TUNEL in skeletal muscle indicated that hypoxia could quickly affect muscle growth and development. Furthermore, we concluded that the Egr2-FasL-Fas signal pathway, which was located at the upstream of apoptotic executor protein caspases, was related to the apoptosis by quantitative real-time PCR, protein concentration detection in ELISA and double gene in situ hybridization methods. The mechanism of the pathway was researched in transcription regulation and epigenetic modification by dual-luciferase reporter assay and bisulfite modified method, respectively. Egr2, as a transcription factor, could up-regulate the expression of FasL gene. And its binding site was mainly between -479 to -1 of FasL gene promoter. The 5th CpG dinucleotides (-514) methylation levels in FasL gene were significantly affected by hypoxia, and they were negatively correlated with its expressions. These suggested that the -514 site may be a very important site to regulate the FasL gene expression. Above results, we concluded that hypoxia activated the immune related signal pathway Egr2-FasL-Fas to induced skeletal muscle apoptosis to affect growth and development of Japanese flounder. The study revealed the mechanism of hypoxia induced apoptosis, which could provide a reference for fish immunity and aquaculture management.

The multifunctional RNA-binding protein Staufen1: an emerging regulator of oncogenesis through its various roles in key cellular events

The double-stranded multifunctional RNA-binding protein (dsRBP) Staufen was initially discovered in insects as a regulator of mRNA localization. Later, its mammalian orthologs have been described in different organisms, including humans. Two human orthologues of Staufen, named Staufen1 (STAU1) and Staufen2 (STAU2), share some structural and functional similarities. However, given their different spatio-temporal expression patterns, each of these orthologues plays distinct roles in cells. In the current review, we focus on the role of STAU1 in cell functions and cancer development. Since its discovery, STAU1 has mostly been studied for its involvement in various aspects of RNA metabolism. Given the pivotal role of RNA metabolism within cells, recent studies have explored the mechanistic impact of STAU1 in a wide variety of cell functions ranging from cell growth to cell death, as well as in various disease states. In particular, there has been increasing attention on the role of STAU1 in neuromuscular disorders, neurodegeneration, and cancer. Here, we provide an overview of the current knowledge on the role of STAU1 in RNA metabolism and cell functions. We also highlight the link between STAU1-mediated control of cellular functions and cancer development, progression, and treatment. Hence, our review emphasizes the potential of STAU1 as a novel biomarker and therapeutic target for cancer diagnosis and treatment, respectively.

Breast milk MSCs upregulated β-cells PDX1, Ngn3, and PCNA expression via remodeling ER stress /inflammatory /apoptotic signaling pathways in type 1 diabetic rats

Type 1 diabetes mellitus (T1DM) is one of the autoimmune diseases characterized by beta-cell dysfunction with serious health complications. Br-MSCs represent a novel valid candidate in regenerative medicine disciplines. Yet, the full potential of Br-MSCs in managing type 1 diabetes remains elusive. Indeed, this study was designed to explore a novel approach investigating the possible regenerative capacity of Br-MSCs in type1 diabetic islet on the level of the cellular mRNA expression of different molecular pathways involved in pancreatic beta-cell dysfunction. Sixty adult male Sprague-Dawley rats were randomly assigned into 3 groups (20 rats each); the control group, type1 diabetic group, and the type 1 diabetic Br-MSCs treated group. And, for the first time, our results revealed that intraperitoneally transplanted Br-MSCs homed to the diabetic islet and improved fasting blood glucose, serum insulin level, pancreatic oxidative stress, upregulated pancreatic mRNA expression for: regenerative markers (Pdx1, Ngn3, PCNA), INS, beta-cell receptors (IRS1, IRβ, PPARγ), pancreatic growth factors (IGF-1, VEGFβ1, FGFβ), anti-inflammatory cytokine (IL10) and anti-apoptotic marker (BCL2) too, Br-MSCs downregulated pancreatic mRNA expression for: inflammatory markers (NFKβ, TNFα, IL1β, IL6, IL8, MCP1), apoptotic markers for both intrinsic and extrinsic pathways (FAS, FAS-L, P53, P38, BAX, Caspase3), ER stress markers (ATF6, ATF3, ATF4, BIP, CHOP, JNK, XBP1) and autophagy inhibitor (mTOR). In conclusion, Br-MSCs could be considered as a new insight in beta cell regenerative therapy improving the deteriorated diabetic islet microenvironment via modulating; ER stress, inflammatory, and apoptotic signaling pathways besides, switching on the cellular quality control system (autophagy) thus enhancing beta-cell function.

Synthetic pyrethroids common metabolite 3-phenoxybenzoic acid induces caspase-3 and Bcl-2 mediated apoptosis in human hepatocyte cells

Synthetic pyrethroids are a group of insecticides frequently used in public health and agriculture, and 3-PBA is a common metabolite of them. Although the liver is the primary organ responsible for metabolizing many compounds including pesticides, to the authors' knowledge there have been no studies on the direct hepatotoxic effects of 3-PBA. Therefore, this study aimed to investigate the possible hepatotoxic effects of 3-PBA on a Human Hepatoma Cell Line (HepG2) and the underlying apoptotic mechanisms. Firstly, an LC₅₀ of 1041.242 µM was calculated for 3-PBA by using the WST-1 test with concentrations ranging between 1 µM and 10 mM. Following that, the HepG2 cells in the experimental group were exposed to 3 different concentrations of 3-PBA (1/5 LC₅₀, 1/10 LC₅₀ and 1/20 LC₅₀) for 24 hours. The apoptotic mechanism was evaluated by using flow cytometry, and immunofluorescence assays for Caspase 3 and Bcl-2. In the flow cytometry assay, the total number of apoptotic cells increased in a dose dependent manner (p < 0.05). In the immunofluorescence assay, the Caspase 3 protein showed strong immunoreactivity in the experimental groups, while the reaction to the Bcl-2 protein was minimal. These results demonstrated that 3-PBA has a significant hepatotoxic effect on HepG2 cells and induces apoptosis via the regulation of Caspase-3 and Bcl-2. Furthermore, our results could further the understanding of the fundamental molecular mechanisms of 3-PBA hepatotoxicity. More studies are needed to determine the effects of long-term exposure to 3-PBA and also the molecular mechanisms underlying hepatotoxicity.

A Novel Nine Apoptosis-Related Genes Signature Predicting Overall Survival for Kidney Renal Clear Cell Carcinoma and its Associations with Immune Infiltration

Background: This study was designed to establish a sensitive prognostic model based on apoptosis-related genes to predict overall survival (OS) in patients with clear cell renal cell carcinoma (ccRCC). Methods: Obtaining the expression of apoptosis-related genes and associated clinical parameters from online datasets (The Cancer Genome Atlas, TCGA), their biological function analyses were performed through differently expressed genes. By means of LASSO, unadjusted and adjusted Cox regression analyses, this predictive signature was constructed and validated by internal and external databases (both TCGA and ArrayExpress). Results: A total of nine apoptosis-related genes (SLC27A2, TNFAIP2, IFI44, CSF2, IL4, MDK, DOCK8, WNT5A, APP) were ultimately screened as associated hub genes and utilized to construct a prognosis model. Then our constructed riskScore model significantly passed the validation in both the internal and external datasets of OS (all p < 0.05) and verified their expressions by qRT-PCR. Moreover, we conducted the Receiver Operating Characteristic (ROC), finding the area under the ROC curves (AUCs) were all above 0.70 which indicated that riskScore was a stable independent prognostic factor (p < 0.05). Furthermore, prognostic nomograms were established to figure out the relationship between 1-, 3- and 5-year OS and individual parameters for ccRCC patients. Additionally, survival analyses indicated that our riskScore worked well in predicting OS in subgroups of age, gender, grade, stage, T, M, N0, White (all p < 0.05), except for African, Asian and N1 (p > 0.05). We also explored its association with immune infiltration and applied cMap database to seek out highly correlated small molecule drugs. Conclusion: Our study successfully constructed a prognostic model containing nine hub apoptosis-related genes for ccRCC, helping clinicians predict patients' OS and making the prognostic assessment more standardized. Future prospective studies are required to validate our findings.

EGF-mediated reduced miR-92a-1-5p controls HTR-8/SVneo cell invasion through activation of MAPK8 and FAS which in turn increase MMP-2/-9 expression

The members of human miR-17-92 cluster are implicated in several cancers and are known to increase cancer cells invasiveness. The present study reports reduced expression of miR-92a-1-5p in EGF treated HTR-8/SVneo trophoblastic cells by NGS and qRT-PCR. Overexpression of miR-92a-1-5p led to significantly reduced EGF-mediated HTR-8/SVneo cells invasion. MAPK8 and FAS were predicted to be miR-92a-1-5p targets, and confirmed to be reduced by qRT-PCR and Western blotting in trophoblast cells overexpressing miR-92a-1-5p. The binding of miR-92a-1-5p to MAPK8 and FAS 3'-UTR was confirmed by Luciferase reporter assay and Rescue assay. EGF increases MMP-2 & MMP-9 expression and reduces TIMP1 expression in HTR-8/SVneo cells. Inhibition of MAPK8 (by SP600125) reduced EGF-mediated MMP-9/TIMP1 ratio and invasion. Similarly, silencing of FAS by siRNA reduced EGF-mediated MMP-2/TIMP1 ratio and invasion. Treatment of HTR-8/SVneo cells with STAT1/3 inhibitors or siRNAs led to loss of EGF-mediated reduction in miR-92a-1-5p levels. Inserting the predicted binding sites of STAT3 present in promoter region of miR-92a-1-5p upstream of Luciferase promoter reduced its expression in presence of STAT3 expression vector. Thus, EGF leads to reduced miR-92a-1-5p expression which may be regulated by STAT1/STAT3 and controls HTR-8/SVneo cells invasion by targeting MAPK8 and FAS, which in turn increases MMP-2/MMP-9 expression.

MiR-145 in cancer therapy resistance and sensitivity: A comprehensive review

MircoRNA (miRNA) are a group of small, non–coding, regulatory RNA with an average length of approximately 22 nucleotides, which mostly modulate gene expression post–transcriptionally through complementary binding to the 3ʹ‐untranslated region (3ʹ‐UTR) of multiple target genes. Emerging evidence has shown that miRNA are frequently dysregulated in a variety of human malignancies. Among them, microRNA‐145 (miR‐145) has been increasingly identified as a critical suppressor of carcinogenesis and therapeutic resistance. Resistance to tumor therapy is a challenge in cancer treatment due to the daunting range of resistance mechanisms. We reviewed the status quo of recent advancements in the knowledge of the functional role of miR‐145 in therapeutic resistance and the tumor microenvironment. It may serve as an innovative biomarker for therapeutic response and cancer prognosis.

Supraphysiological Concentrations of Bisphenol A Alter the Expression of Extracellular Vesicle-Enriched miRNAs From Human Primary Granulosa Cells

Bisphenol A (BPA) is a widely used chemical that has been detected in follicular fluid and associated with adverse reproductive effects. Granulosa cells have an important role in follicular growth and oocyte maturation, however, little is known about the biological mechanisms of BPA toxicity on human granulosa cells. In this study, we exposed primary granulosa cells to different concentrations of BPA (0, 20, 200, 2000, and 20 000 ng/ml) and used quantitative polymerase chain reaction to measure the expression levels of miRNAs enriched in extracellular vesicles (EV-enriched miRNAs), and cellular levels of selected target genes of differentially expressed EV-enriched miRNAs. We found that exposure to 20 000 ng/ml BPA was associated with decreased levels of EV-miR-27b-3p (FC = 0.58, p = .04) and increased levels of its biologically relevant target genes FADD (FC = 1.22, p = .01), IGF1 (FC = 1.59, p = .06), and PPARG (FC = 1.73, p = .001) as compared with the control. In addition, we observed that under the same exposure conditions, the expression levels of miR-27b-3p in granulosa cells were also downregulated (FC = 0.65, p = .03) as compared with the control. Our findings suggest that both cellular and extracellular changes in gene expression may mediate BPA toxicity in granulosa cells.

OGR1 negatively regulates β-casein and triglyceride synthesis and cell proliferation via the PI3K/AKT/mTOR signaling pathway in goat mammary epithelial cells

Goat milk in some cases is less allergenic than cow milk, therefore, more people drink goat milk in the world, so it is necessary for us to improve the yield and quality of goat milk. Previous studies have shown that some genes are closely related to lactation. Ovarian cancer G protein-coupled 1 (OGR1) is a G protein-coupled receptor discovered recently. OGR1 is widely found in various tissues of organisms and is involved in cell skeleton reorganization, carcinogenesis, cell proliferation, and apoptosis by regulating multiple signaling pathways in cells. However, the modulating effect of OGR1 in lactation is still unknown. Therefore, the objective of this study is to investigate the function of OGR1 in goat mammary epithelial cells (GMECs). Flow cytometry, CCK8, EDU, enzyme-linked immunosorbent assay, and triglyceride test kit assays were performed and we found that OGR1 regulated Bcl-2/Bax ratio, Fas protein expression as well as the phosphorylation of AKT and mammalian target of rapamycin (mTOR). si-OGR1 could enhance the proliferation of GMECs by promoting G1/S phase progression and the synthesis of β-casein and triglyceride. By contrast, OGR1 repressed GMECs proliferation and down-regulated the synthesis of β-casein and triglyceride by blocking the PI3K/AKT/mTOR signaling pathway in GMECs.

The effect of high mobility group box-1 protein on cerebral edema, blood-brain barrier, oxidative stress and apoptosis in an experimental traumatic brain injury model

Traumatic brain injury (TBI) is one of the important reason of morbidity and mortality. While the primary injury due to mechanical impact is unavoidable, the secondary injury which is formed as a result of primary injury and thought to occur due to neuroinflammation in the forefront can be prevented and by this way mortality and morbidity can be reduced. High mobility group box-1 (HMGB1) is a protein that triggers the neuroinflammatory process by being released from the nucleus of necrotic tissues after primary injury. The aim of this study is to investigate the effects of HMGB1 on its receptors TLR4 and RAGE, cerebral edema, blood-brain barrier, oxidative stress and apoptosis causing secondary damage in an experimental traumatic brain injury model. Weighing between 280-320 g, 10 to 12 weeks-old, a total of 30 adult male Sprague-Dawley rats were used for the experiments. The rats were randomly assigned to 3 groups: 1) Control, 2) TBI and 3) TBI + ethyl pyruvate group (n = 10 per group). Right parietal cortical contusion was made by using a weight-dropping TBI method. Brain samples were harvested from pericontusional area at 24 h after TBI. HMGB1, TLR4, RAGE, occludin, claudin-5, ZO-1 levels are investigated by western blot analyses and immunohistochemistry examinations. HMGB-1, TLR4 and RAGE expressions increased after TBI. Major tight junction proteins in the blood-brain barrier: occludin, claudin-5 and ZO-1 expressions decreased after TBI. Brain edema increased after TBI. Also, proapoptotic bax and active caspase 3 expressions increased, antiapoptotic bcl-2 levels decreased after TBI. Total oxidant status and oxidative stress increased, total antioxidant status decreased after TBI. HMGB-1 protein plays a key role in the pathophysiology of traumatic brain injury.

Targeting Type 1 Diabetes: Selective Approaches for New Therapies

The clinical onset of type 1 diabetes is characterized by the destruction of the insulin-producing β cells of the pancreas and is caused by autoantigen-induced inflammation (insulitis) of the islets of Langerhans. The current standard of care for type 1 diabetes mellitus patients allows for management of the disease with exogenous insulin, but patients eventually succumb to many chronic complications such as limb amputation, blindness, and kidney failure. New therapeutic approaches now on the horizon are looking beyond glycemic management and are evaluating new strategies from protecting and regenerating endogenous islets to treating the underlying autoimmunity through selective modulation of key immune cell populations. Currently, there are no effective treatments for the autoimmunity that causes the disease, and strategies that aim to delay or prevent the onset of the disease will play an important role in the future of diabetes research. In this review, we summarize many of the key efforts underway that utilize molecular approaches to selectively modulate this disease and look at new therapeutic paradigms that can transform clinical treatment.

Investigation of the Relation Between FAS, FASLG Polymorphisms and Serum Fas, FasL Levels in Patients with Psoriasis

Background: Psoriasis is a multifactorial and inflammatory chronic skin disease indicated with T-cell-mediated keratinocyte hyper-proliferation. Demographic, epidemiological (family, twin), serological, and genetic studies have clearly demonstrated that psoriasis is a polygenic and multifactorial disease.

Aim: The objectives of the study are; to determine the prevalence of the polymorphisms of FAS (Fas cell surface receptor gene) -671 A>G (rs:1800682) and FASLG (Fas ligand gene) -844 T>C (rs:763110), to investigate the serum levels of sFas and sFasL, and also to discover any relationship between gene polymorphisms and serum levels in psoriatic patients.

Material and Methods: 50 treated and 69 untreated patients, and 140 healthy controls were included in the study. Polymorphisms were determined using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. The serum levels were measured in randomly selected treated (39) and untreated (40) patients, also in 84 healthy controls using micro-ELISA technique.

Results: There was no statistical difference between polymorphisms in the patient and control groups. However, sFas and sFasL levels in both treated and untreated patients were higher than that of the controls.

Conclusion: The investigated FAS and FASLG polymorphisms were not found to be directly associated with the psoriasis. Elevated sFas and sFasL levels in psoriatic patients showed that these factors may possess a significant role in the pathogenesis of psoriasis.

Tetrahydroxystilbene Glucoside Effectively Prevents Apoptosis Induced Hair Loss

The effect of Polygonum multiflorum against hair loss has been widely recognized. 2,3,5,4′-Tetrahydroxystilbene-2-O-β-D-glucoside (TSG) is the main component of Polygonum multiflorum; however, its role in hair regeneration has not been established. To evaluate the hair growth-promoting activity of TSG, depilated C57BL/6J mice were topically treated with normal saline, TSG, Pifithrin-α, Minoxidil for 2 weeks. In this study, we identified that p53, Caspase-3, Active Caspase-3, and Caspase-9 were obviously upregulated in the skin of human and mice with hair loss by western blot analysis. Depilated mice treated with TSG showed markedly hair regrowth. TUNEL⁺ cells were also reduced in mice with TSG. These changes were accompanied with inhibition of Fas, p53, Bax, Active Caspase-3, and Procaspase-9 activities. These results demonstrated that TSG exerts great hair regrowth effect on hair loss, which was probably mediated by inhibition of p53, Fas, and Bax induced apoptosis.

Dysfunctional signaling underlying endometriosis: current state of knowledge

Endometriosis is defined as the presence of endometrial tissue outside the uterine cavity. It affects approximately 5-10% of women of reproductive age. Endometriosis is associated with dysmenorrhea, dyspareunia and, often, severe pelvic pain. In addition to pain, women with endometriosis often experience infertility. Defining the molecular etiology of endometriosis is a significant challenge for improving the quality of women's lives. Unfortunately, the pathophysiology of endometriosis is not well understood. Here, we summarize the potential causative factors of endometriosis in the following three categories: (1) dysregulation of immune cells in the peritoneal fluid and endometriotic lesions; (2) alteration of apoptotic signaling in retrograde menstrual tissue and cytotoxic T cells involved in endometriosis progression and (3) dysregulation of oxidative stress. Determining the molecular etiology of these dysregulated cellular signaling pathways should provide crucial clues for understanding initiation and progression of endometriosis. Moreover, improved understanding should suggest new molecular therapeutic targets that could improve the specificity of endometriosis treatments and reduce the side effects associated with current approaches.

Mitochondrial dysfunction and oxidative stress in aging and cancer

Aging and cancer are the most important issues to research. The population in the world is growing older, and the incidence of cancer increases with age. There is no doubt about the linkage between aging and cancer. However, the molecular mechanisms underlying this association are still unknown. Several lines of evidence suggest that the oxidative stress as a cause and/or consequence of the mitochondrial dysfunction is one of the main drivers of these processes. Increasing ROS levels and products of the oxidative stress, which occur in aging and age-related disorders, were also found in cancer. This review focuses on the similarities between ageing-associated and cancer-associated oxidative stress and mitochondrial dysfunction as their common phenotype.

Fas signaling induces stemness properties in colorectal cancer by regulation of Bmi1

Fas signaling promotes colorectal cancer (CRC) metastasis by inducing epithelial-mesenchymal transition (EMT). The acquisition of EMT properties in turn induces stemness but the mechanism by which Fas signaling contributes to it still remains unclear. Hence, the aim of this study was to investigate how Fas signaling regulates CRC stemness. For this purpose, soft agar assay, sphere formation assay, cell survival analysis, immunoblot, qRT-PCR, chromatin immunoprecipitation, and luciferase reporter assay were performed. Expression of FasL, Bmi1, and the miR-200c in CRC specimens was examined through immunohistochemistry, qRT-PCR, and immunoblot. In our study, Fas signaling induced stem cell properties in CRC specimens, relying on ERK1/2 MAPK pathway, with Bmi1 being mainly responsible for FasL-induced stemness. FasL treatment promoted Bmi1 expression by inhibiting miR-200c, which targets Bmi1 3'UTR region. Furthermore, FasL-induced Zeb1 binded with miR-200c promoter and inhibited its expression. Moreover, FasL-induced β-catenin nuclear expression promoted Zeb1 expression by binding with Zeb1 promoter. GSK-3β, which regulates β-catenin, was inhibited by FasL-induced ERK1/2 MAPK signaling. Finally, FasL and Bmi1 expression in clinical samples increased during CRC progression, and a positive correlation between them was observed. Patients with high FasL and Bmi1 expression had a worse prognosis than patients with low expression. In conclusion, our results showed that Fas signaling can promote stemness in CRC through the modulation of Bmi1 expression via the ERK1/2 MAPK/GSK-3β/β-catenin/Zeb1/miR-200c axis, suggesting that Fas signaling-based cancer therapies should be administered cautiously, as the activation of this pathway not only leads to apoptosis but also induces stemness in CRC.

Splicing factors of SR and hnRNP families as regulators of apoptosis in cancer

SR and hnRNP proteins were initially discovered as regulators of alternative splicing: the process of controlled removal of introns and selective joining of exons through which multiple transcripts and, subsequently, proteins can be expressed from a single gene. Alternative splicing affects genes involved in all crucial cellular processes, including apoptosis. During cancerogenesis impaired apoptotic control facilitates survival of cells bearing molecular aberrations, contributing to their unrestricted proliferation and chemoresistance. Apparently, SR and hnRNP proteins regulate all levels of expression of apoptotic genes, including transcription initiation and elongation, alternative splicing, mRNA stability, translation, and protein degradation. The frequently disturbed expressions of SR/hnRNP proteins in cancers lead to impaired functioning of target apoptotic genes, including regulators of the extrinsic (Fas, caspase-8, caspase-2, c-FLIP) and the intrinsic pathway (Apaf-1, caspase-9, ICAD), genes encoding Bcl-2 proteins, IAPs, and p53 tumor suppressor. Prototypical members of SR/hnRNP families, SRSF1 and hnRNP A1, promote synthesis of anti-apoptotic splice variants of Bcl-x and Mcl-1, which results in attenuation of programmed cell death in breast cancer and chronic myeloid leukemia. SR/hnRNP proteins significantly affect responses to chemotherapy, acting as mediators or modulators of drug-induced apoptosis. Aberrant expression of SRSF1 and hnRNP K can interfere with tumor responses to chemotherapy in pancreatic and liver cancers. Currently, a number of splicing factor inhibitors is being tested in pre-clinical and clinical trials. In this review we discuss recent findings on the role of SR and hnRNP proteins in apoptotic control in cancer cells as well as their significance in anticancer treatments.

Knockdown of Decoy Receptor 3 Impairs Growth and Invasiveness of Hepatocellular Carcinoma Cell Line of HepG2

Background:

Decoy receptor 3 (DcR3) binds to Fas ligand (FasL) and inhibits FasL-induced apoptosis. The receptor is overexpressed in hepatocellular carcinoma (HCC), and it is associated with the growth and metastatic spread of tumors. DcR3 holds promises as a new target for the treatment of HCC, but little is known regarding the molecular mechanisms underlying the oncogenic properties of DcR3. The present work, therefore, examined the role of DcR3 in regulating the growth and invasive property of liver cancer cell HepG2.

Methods:

HepG2 cells were stably transfected with lentivirus-based short hairpin RNA vector targeting DcR3. After the knockdown of DcR3 was confirmed, cell proliferation, clone formation, ability of migrating across transwell membrane, and wound healing were assessed in vitro. Matrix metalloproteinase-9 (MMP 9) and vascular epithelial growth factor (VEGF)-C and D expressions of the DcR3 knockdown were also studied. Comparisons between multiple groups were done using one-way analysis of variance (ANOVA), while pairwise comparisons were performed using Student's t test. P < 0.05 was regarded statistically significant.

Results:

DcR3 was overexpressed in HepG2 compared to other HCC cell lines and normal hepatocyte Lo-2. Stable knockdown of DcR3 slowed down the growth of HepG2 (P < 0.05) and reduced the number of clones formed by 50% compared to those without DcR3 knockdown (P < 0.05). The knockdown also reduced the migration of HepG2 across transwell matrix membrane by five folds compared to the control (P < 0.05) and suppressed the closure of scratch wound (P < 0.05). In addition, the messenger RNA levels of MMP 9, VEGF-C, and VEGF-D were significantly suppressed by DcR3 knockdown by 90% when compared with the mock control (P < 0.05).

Conclusions:

Loss of DcR3 impaired the growth and invasive property of HCC cell line of HepG2. Targeting DcR3 may be a potential therapeutic approach for the treatment of HCC.

Anti-Fas Antibody Conjugated Nanoparticles Enhancing the Antitumor Effect of Camptothecin by Activating the Fas-FasL Apoptotic Pathway

Emerging evidence suggest that the introduction of Fas ligand (FasL) can enhance the Fas-dependent apoptosis and induce durable immune responses against tumor. However, selective triggering of apoptosis in tumor cells while sparing normal cells remains a great challenge for the application of FasL-based therapeutic strategies. Herein, smart nanoparticles (NPs) with a sandwich structure were fabricated. These NPs consist of a matrix metalloproteinase (MMP) cleavable PEG outer layer, an anti-Fas antibody middle layer, and a camptothecin (CPT)-loaded inner core. They could accumulate at a tumor site by the enhanced permeability and retention (EPR) effect. The removable PEG layer protects the cytotoxic anti-Fas antibody from premature contact with normal tissues, thus avoiding the unexpected lethal side effect before they reach the tumor site. Due to the high level of MMP expressed by tumor cells inside the tumor tissue, these NPs would shed their PEG layers, resulting in the exposure of anti-Fas antibody to bind the Fas receptor and triggering the apoptosis of tumor cells. Results of Western blot confirmed that these NPs could mimic the function of activated cytotoxic lymphocyte (CTL) to activate the Fas-FasL apoptosis pathway of tumor cells. With the aid of CPT payload, these anti-Fas antibody conjugated NPs achieved a high tumor inhibition in the B16 allograft tumor animal model. The design of these NPs provides a method for delivering cytotoxic ligand to targeting tissue, which may be valuable in cancer therapy.

Protocadherin γ A3 is expressed in follicular lymphoma irrespective of BCL2 status and is associated with tumor cell growth

Protocadherin genes (PCDHs) have been suggested to act as tumor suppressor genes in various tumor types. Previous studies have demonstrated the upregulation of certain PCDH-γ subfamily genes in nodal and duodenal follicular lymphoma (FL) using gene expression analyses. However, the mechanisms and associated molecular function of PCDH-γ subfamily gene upregulation in FL remain to be elucidated. The present study examined the expression of PCDHGA3, an upregulated PCDH-γ gene subfamily member, in B-cell lymphoma 2 (BCL2)-positive and -negative FL, and evaluated its association with tumor cell proliferation in an FL-derived cell line. Immunohistochemical analysis demonstrated that the majority of FL grade 1–2 samples (19/20; 95%) and over half of grade 3A FL samples (5/9; 56%) were PCDHGA3-positive, whereas only 1/17 reactive lymphoid hyperplasia samples was positive. Notably, this positivity was widely observed in samples of BCL2-negative FL (13/15; 87%) and FL with diffuse area (10/10; 100%). The FL-derived cell line FL18 exhibited strong PCDHGA3 expression, similar to the patient samples, and its proliferation was suppressed by PCDHGA3 gene knockdown. Genes expressed concomitantly with PCDHGA3 were selected from gene expression data, and TNFRSF6B, a member of the tumor necrosis factor receptor superfamily, was among the top five most strongly correlated genes. Coexpression of TNFRSF6B and PCDHGA3 was observed immunohistochemically in FL18 cells, suggesting potential cooperation in tumor cell maintenance. In conclusion, the results of the present study indicated that PCDHGA3 was expressed in FL irrespective of BCL2 status and grading and was associated with cell proliferation. Further studies involving molecular genetic analyses are required to elucidate the mechanisms underlying the activity of PCDHGA3 in FL.

Inhibition of neutrophil activity in cardiac surgery with cardiopulmonary bypass: a novel strategy with the leukocyte inhibition module

Recently, we showed that the arterial in-line application of the leukocyte inhibition module (LIM) within the heart-lung machine limits overshooting leukocyte activity and cardiac tissue damage. Moreover, significantly better cardiac function was found in an experimental animal model when LIM was used. In the meantime, the first promising clinical data exist. LIM has to be regarded as an essential tool in extracorporeal circulation, in the future, to improve postoperative clinical outcome and to reduce costs. This review summarizes the biological background of LIM and the current experience obtained in experimental models and clinical studies.

Research Advances on Pathways of Nickel-Induced Apoptosis

High concentrations of nickel (Ni) are harmful to humans and animals. Ni targets a number of organs and produces multiple toxic effects. Apoptosis is important in Ni-induced toxicity of the kidneys, liver, nerves, and immune system. Apoptotic pathways mediated by reactive oxygen species (ROS), mitochondria, endoplasmic reticulum (ER), Fas, and c-Myc participate in Ni-induced cell apoptosis. However, the exact mechanism of apoptosis caused by Ni is still unclear. Understanding the mechanism of Ni-induced apoptosis may help in designing measures to prevent Ni toxicity.

Fas signaling promotes chemoresistance in gastrointestinal cancer by up-regulating P-glycoprotein

Fas signaling promotes metastasis of gastrointestinal (GI) cancer cells by inducing epithelial-mesenchymal transition (EMT), and EMT acquisition has been found to cause cancer chemoresistance. Here, we demonstrated that the response to chemotherapy of GI cancer patients with higher expression of FasL was significantly worse than patients with lower expression. Fas-induced activation of the ERK1/2-MAPK pathway decreased the sensitivity of GI cancer cells to chemotherapeutic agents and promoted the expression of P-glycoprotein (P-gp). FasL promoted chemoresistance of GI cancer cell via upregulation of P-gp by increasing β-catenin and decreasing miR-145. β-catenin promoted P-gp gene transcription by binding with P-gp promoter while miR-145 suppressed P-gp expression by interacting with the mRNA 3'UTR of P-gp. Immunostaining and qRT-PCR analysis of human GI cancer samples revealed a positive association among FasL, β-catenin, and P-gp, but a negative correlation between miR-145 and FasL or P-gp. Altogether, our results showed Fas signaling could promote chemoresistance in GI cancer through modulation of P-gp expression by β-catenin and miR-145. Our findings suggest that Fas signaling-based cancer therapies should be administered cautiously, as activation of this pathway may not only lead to apoptosis but also induce chemoresistance.

Exercise, Autophagy, and Apoptosis

Exercise is a form of physiological stress which is known to induce an adaptational response. It is proposed that both apoptosis and autophagy are processes which are necessary for adaptation to exercise. Apoptosis and autophagy are induced during exercise to limit tissue damage, restore tissue integrity, terminate inflammatory responses, or induce direct signals for adaptation. Apoptosis is induced by specific mediators like reactive oxygen species, cytokines, and hormones. Autophagic pathways are activated by altered proteins/organelles with the aim to conserve and recycle the cellular resources. In this case, the cell is flooded with damaged molecules, the repairing mechanisms are overtaxed, and apoptosis is induced. In conclusion, autophagy seems to be necessary for adaptation by providing locally the conditions for muscle plasticity and apoptosis systemically by mobilizing progenitor cells.

Subcellular localization of DAXX influence ox-LDL induced apoptosis in macrophages

Here we aimed to evaluate the effects of DAXX subcellular localization on ox-LDL induced macrophages apoptosis. Cytoplasmic localization vector DAXX-W621A and nuclear localization vector DAXX-S667A were constructed by point mutation in DAXX. Blank vector, full length DAXX, DAXX-W621A, DAXX-S667A was transfect into RAW264.7 cells, respectively. Then the cells were incubated with 100 mg/ml ox-LDL for 48 h. Immunofluorescent assay was used to assay the localization of DAXX. MTT and Flow cytometry was used to determine cellular viability and apoptosis. RT-PCR and Western blot were used to analyze the expression levels. A significantly increased expression of DAXX was found in transfected cells of DAXX. The content of DAXX in nucleus was significantly increased in DAXX(S667A), and DAXX was significantly increased in cytoplasm of DAXX(W621A). Besides, we found DAXX was mainly expressed in nucleus with a low-level expression in cytoplasm through immunofluorescence. However in DAXX(W621A) group, the DAXX began to transferred to cytoplasm, which exhibited significant florescence. After treated with ox-LDL, the cytoactive of DAXX-W621A exhibited significantly decreased level when compared DAXX group. However, after added inhibitor LMB, the inhibition was relieved. The cell viability was also significantly increased in DAXX-S667A group. The results of apoptosis rates were similar in each group. Furthermore, we found the expression of ASK1 and JNK was also consistent with the apoptosis rates. Cytoplasmic localization of DAXX can increase injury sensitivity of ox-LDL on cells, and nuclear localization can antagonise the effect of ox-LDL. Besides, it is certified ox-LDL induced apoptosis is mainly through ASK1-JNK pathway.

Molecular mechanisms of luteolin-7-O-glucoside-induced growth inhibition on human liver cancer cells: G2/M cell cycle arrest and caspase-independent apoptotic signaling pathways

Luteolin-7-O-glucoside (LUT7G), a flavone subclass of flavonoids, has been found to increase anti-oxidant and anti-inflammatory activity, as well as cytotoxic effects. However, the mechanism of how LUT7G induces apoptosis and regulates cell cycles remains poorly understood. In this study, we examined the effects of LUT7G on the growth inhibition of tumors, cell cycle arrest, induction of ROS generation, and the involved signaling pathway in human hepatocarcinoma HepG2 cells. The proliferation of HepG2 cells was decreased by LUT7G in a dose-dependent manner. The growth inhibition was due primarily to the G2/M phase arrest and ROS generation. Moreover, the phosphorylation of JNK was increased by LUT7G. These results suggest that the anti-proliferative effect of LUT7G on HepG2 is associated with G2/M phase cell cycle arrest by JNK activation.

Complex changes in the apoptotic and cell differentiation programs during initiation of the hair follicle response to chemotherapy

Chemotherapy has severe side-effects for normal rapidly proliferating organs, such as hair follicle, and causes massive apoptosis in hair matrix keratinocytes followed by hair loss. To define the molecular signature of hair follicle response to chemotherapy, human scalp hair follicles cultured ex vivo were treated with doxorubicin and global microarray analysis was performed 3 hours after treatment. Microarray data revealed changes in expression of 504 genes in doxorubicin-treated hair follicles versus the controls. Among these genes, upregulations of several tumor necrosis factor family of apoptotic receptors (FAS, TRAIL receptors 1/2), as well as of a large number of the keratin-associated protein genes were seen after doxorubicin treatment. Hair follicle apoptosis induced by doxorubicin was significantly inhibited by either TRAIL neutralizing antibody or caspase 8 inhibitor, thus suggesting a novel role for TRAIL receptor signaling in mediating doxorubicin-induced hair loss. These data demonstrate that the early phase of the hair follicle response to doxorubicin includes upregulation of apoptosis-associated markers, as well as substantial re-organization of the terminal differentiation programs in hair follicle keratinocytes. These data provide an important platform for further studies towards the design of novel approaches for management of chemotherapy-induced hair loss.

Acellular fraction of ovarian cancer ascites induce apoptosis by activating JNK and inducing BRCA1, Fas and FasL expression in ovarian cancer cells

Acellular fraction of ascites might play an active role in tumor development. Nevertheless the mechanisms involved in the tumor-modulating properties are still controversial. Here, we demonstrate that malignant ascites from 8 patients with epithelial ovarian cancer did not influence proliferative or invasive properties of ovarian cancer cells, but promoted H₂O₂-induced apoptosis and increased sensitivity to paclitaxel. Malignant ascites induced BRCA1, Fas and FasL expression and phosphorylation of JNK, but not the activation of caspase pathway. Ascites-induced apoptosis of ovarian cancer cells was strongly inhibited by a JNK inhibitor suggesting a critical role of JNK pathway in ascite-induced apoptosis. The use of siRNA JNK confirmed the importance of JNK in ascites-induced Fas and FasL expression. These results demonstrate that malignant ascites induce apoptosis of ovarian cancer cells and encourage us to think about the clinical management of ovarian cancer patients with malignant ascites.

Global gene expression analysis reveals a link between NDRG1 and vesicle transport

N-myc downstream-regulated gene 1 (NDRG1) is induced by cellular stress such as hypoxia and DNA damage, and in humans, germ line mutations cause Charcot-Marie-Tooth disease. However, the cellular roles of NDRG1 are not fully understood. Previously, NDRG1 was shown to mediate doxorubicin resistance under hypoxia, suggesting a role for NDRG1 in cell survival under these conditions. We found decreased apoptosis in doxorubicin-treated cells expressing NDRG1 shRNAs under normoxia, demonstrating a requirement for NDRG1 in apoptosis in breast epithelial cells under normal oxygen pressure. Also, different cellular stress regimens, such as hypoxia and doxorubicin treatment, induced NDRG1 through different stress signalling pathways. We further compared expression profiles in human breast epithelial cells ectopically over-expressing NDRG1 with cells expressing NDRG1 shRNAs in order to identify biological pathways where NDRG1 is involved. The results suggest that NDRG1 may have roles connected to vesicle transport.

Hydrogen peroxide activation of ERK5 confers resistance to Jurkat cells against apoptosis induced by the extrinsic pathway

Reactive oxygen species (ROS) including hydrogen peroxide (H₂O₂) exhibit both pro-survival and pro-death signaling in leukemic cells. We examined the effect of exogenous H₂O₂ on Fas ligand (FasL) -induced apoptosis in Jurkat cells. H₂O₂ applied prior to (pre-conditioning) and during (post-conditioning) FasL stimulation attenuated early apoptosis through activation of EKR5. H₂O₂ increased the activated caspase-8 sequestered in the mitochondria thereby decreasing cell death through the extrinsic apoptotic pathway. In addition, inhibition of a protein tyrosine phosphatase likely explains the post-conditioning requirement for H₂O₂. Given that chemotherapeutic agents used for the treatment of acute lymphoblastic leukemia are thought to work partly through production of ROS, a simultaneous inhibition of the ERK5 pathway may abrogate the ROS-initiated pro-survival signaling for an enhanced cell kill.

Imprinted and X-linked non-coding RNAs as potential regulators of human placental function

Pregnancy outcome is inextricably linked to placental development, which is strictly controlled temporally and spatially through mechanisms that are only partially understood. However, increasing evidence suggests non-coding RNAs (ncRNAs) direct and regulate a considerable number of biological processes and therefore may constitute a previously hidden layer of regulatory information in the placenta. Many ncRNAs, including both microRNAs and long non-coding transcripts, show almost exclusive or predominant expression in the placenta compared with other somatic tissues and display altered expression patterns in placentas from complicated pregnancies. In this review, we explore the results of recent genome-scale and single gene expression studies using human placental tissue, but include studies in the mouse where human data are lacking. Our review focuses on the ncRNAs epigenetically regulated through genomic imprinting or X-chromosome inactivation and includes recent evidence surrounding the H19 lincRNA, the imprinted C19MC cluster microRNAs, and X-linked miRNAs associated with pregnancy complications.

miR-23a inhibits E-cadherin expression and is regulated by AP-1 and NFAT4 complex during Fas-induced EMT in gastrointestinal cancer

Fas signaling has been shown to induce the epithelial-mesenchymal transition (EMT) to promote gastrointestinal (GI) cancer metastasis, but the involvement of microRNA in this mechanism remains unknown. We found that Fas ligand (FasL) treatment inhibited E-cadherin expression and promoted cell invasion by upregulation of miR-23a, but overexpression of the miR-23a inhibitor could partially block this activity. FasL-induced extracellular signal-regulated kinase/mitogen-activated protein kinase signaling activated the activator protein 1 (AP-1) complex and repressed glycogen synthase kinase-3β activity, which contributed to nuclear translocation of AP-1 and nuclear factor of activated T cells (NFAT4). Nuclear accumulation and interaction of AP-1 and NFAT4 and subsequent binding to the miR-23a promoter led to increased miR-23a expression. Inhibition of Fas signaling by downregulation of the Fas receptor led to a decrease in miR-23a expression and cell invasion ability in vivo and in vitro, as well as an increase in E-cadherin. Evaluation of human GI precancerous and cancer specimens showed that the expression of FasL and miR-23a increased, whereas the expression of E-cadherin decreased during GI cancer progression. A significant correlation was noted between any two of these three molecules. An EMT phenotype was shown to correlate with an advanced cancer stage and worse prognosis. Taken together, our results show that miR-23a participates in the mechanism of the FasL-induced EMT process and may serve as a potential therapeutic target for cancer metastasis.

Cellular mechanisms controlling caspase activation and function

Caspases are the primary drivers of apoptotic cell death, cleaving cellular proteins that are critical for dismantling the dying cell. Initially translated as inactive zymogenic precursors, caspases are activated in response to a variety of cell death stimuli. In addition to factors required for their direct activation (e.g., dimerizing adaptor proteins in the case of initiator caspases that lie at the apex of apoptotic signaling cascades), caspases are regulated by a variety of cellular factors in a myriad of physiological and pathological settings. For example, caspases may be modified posttranslationally (e.g., by phosphorylation or ubiquitylation) or through interaction of modulatory factors with either the zymogenic or active form of a caspase, altering its activation and/or activity. These regulatory events may inhibit or enhance enzymatic activity or may affect activity toward particular cellular substrates. Finally, there is emerging literature to suggest that caspases can participate in a variety of cellular processes unrelated to apoptotic cell death. In these settings, it is particularly important that caspases are maintained under stringent control to avoid inadvertent cell death. It is likely that continued examination of these processes will reveal new mechanisms of caspase regulation with implications well beyond control of apoptotic cell death.

Glycogen synthase kinase-3 beta regulates Snail and β-catenin expression during Fas-induced epithelial-mesenchymal transition in gastrointestinal cancer

Fas signalling has been shown to induce the epithelial-mesenchymal transition (EMT) to promote gastrointestinal (GI) cancer metastasis, but its mechanism of action is still unknown. The effects of Fas-ligand (FasL) treatment and inhibition of Fas signalling on GI cancer cells were tested using invasion assay, immunofluorescence, immunoblot, Reverse Transcription Polymerase Chain Reaction (RT-PCR), quantitative Real-time PCR (qRT-PCR), immunoprecipitation and luciferase reporter assay. Immunohistochemistry was used to analyse the EMT-associated molecules in GI cancer specimens. FasL treatment inhibited E-cadherin transcription by upregulation of Snail in GI cancer cells. The nuclear expression and transcriptional activity of Snail and β-catenin were increased by inhibitory phosphorylation of glycogen synthase kinase-3 beta (GSK-3β) at Ser9 by FasL-induced extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK) signalling. Snail associated with β-catenin in the nucleus and, thus, increased β-catenin transcriptional activity. Evaluation of human GI cancer specimens showed that the expression of FasL, phospho-GSK-3β, Snail and β-catenin increase during GI cancer progression. An EMT phenotype was shown to correlate with an advanced cancer stage, and a non-EMT phenotype significantly correlated with a better prognosis. Collectively, these data indicate that GSK-3β regulates Snail and β-catenin expression during Fas-induced EMT in gastrointestinal cancer.

Constitutive activity of Erk1/2 and NF-κB protects human endometrial stromal cells from death receptor-mediated apoptosis

Apoptosis in the human endometrium plays an essential role for endometrial receptivity and early implantation. A dysbalance of pro- and anti-apoptotic events in the secretory endometrium seems to be involved in implantation disorders and consecutive pregnancy complications. However, little is known about the mechanisms regulating apoptosis-sensitivity in the human endometrium. Therefore this study was performed to identify molecular mechanisms underlying the resistance toward apoptosis in human endometrial stromal cells (ESCs). Human ESCs were isolated from hysterectomy specimens and used as undifferentiated cells or after decidualization in vitro. Cells were incubated with an activating anti-Fas antibody, tumor-necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), TNF-α and inhibitors of protein- and RNA-syntheses, a caspase-inhibitor and inhibitors of extracellular signal regulated kinase (Erk)1/2, nuclear factor (NF)-κB and Akt. Apoptosis was measured by flow cytometric detection of hypodiploid nuclei. Caspase-activity was detected by luminescencent assays. Several pro- and anti-apoptotic molecules and the activation of Erk1/2, NF-κB and Akt were analyzed by in-cell Western assays or flow cytometry. Inhibition of protein- and RNA-syntheses differentially sensitized human ESCs for death receptor-mediated apoptosis in a caspase-dependent manner, based on the up-regulation of the death receptors Fas and TRAIL-R2. The constitutive activity of Erk1/2 and NF-κB could be identified as a reason for the apoptosis-resistance of human ESCs. These results suggest the pro-survival signaling pathways Erk1/2 and NF-κB as key regulators of the sensitivity of human ESCs for death receptor-mediated apoptosis. The modulation of these pathways might play an important role in the physiology of implantation.

Induction of rapid T cell death and phagocytic activity by Fas-deficient lpr macrophages

Peripheral T cells are maintained by the apoptosis of activated T cells through the Fas-Fas ligand system. Although it is well known that normal T cells fail to survive in the Fas-deficient immune condition, the molecular mechanism for the phenomenon has yet to be elucidated. In this study, we demonstrate that rapid cell death and clearance of normal T cells were induced by Fas-deficient lpr macrophages. Transfer of normal T cells into lpr mice revealed that Fas expression on donor T cells was promptly enhanced through the IFN-γ/IFN-γR. In addition, Fas ligand expression and phagocytic activity of lpr macrophages were promoted through increased NF-κB activation. Controlling Fas expression on macrophages plays an essential role in maintaining T cell homeostasis in the peripheral immune system. Our data suggest a critical implication to the therapeutic strategies such as transplantation and immunotherapy for immune disorder or autoimmunity related to abnormal Fas expression.

Characterization of cytotoxicity-related gene expression in response to virulent Marek's disease virus infection in the bursa of Fabricius

Cell-mediated cytotoxic responses are critical for control of Marek's disease virus (MDV) infection and tumour development. However, the mechanisms of virus clearance mediated by cytotoxic responses in the bursa of Fabricius of chickens during MDV infection are not fully understood. In this study, the host cytotoxic responses during MDV infection in the bursa were investigated by examining the expression of genes in the cell lysis pathways. Partial up-regulation existed in the expression of the important cytolytic molecule granzyme A (GzmA), Fas, NK lysin and DNA repair enzyme Ape1, whereas little or no expression appeared in other cytolytic molecules, including perforin (PFN) and Fas ligand (FasL), and molecules involved in DNA repair and apoptosis in the bursa during MDV infection. These results suggest that less sustained cytotoxic activities are generated in the bursa of MDV-infected chickens. The findings of this study provide a more detailed insight into the host cytotoxic responses to MDV infection.

Topological and functional properties of the small GTPases protein interaction network

Small GTP binding proteins of the Ras superfamily (Ras, Rho, Rab, Arf, and Ran) regulate key cellular processes such as signal transduction, cell proliferation, cell motility, and vesicle transport. A great deal of experimental evidence supports the existence of signaling cascades and feedback loops within and among the small GTPase subfamilies suggesting that these proteins function in a coordinated and cooperative manner. The interplay occurs largely through association with bi-partite regulatory and effector proteins but can also occur through the active form of the small GTPases themselves. In order to understand the connectivity of the small GTPases signaling routes, a systems-level approach that analyzes data describing direct and indirect interactions was used to construct the small GTPases protein interaction network. The data were curated from the Search Tool for the Retrieval of Interacting Genes (STRING) database and include only experimentally validated interactions. The network method enables the conceptualization of the overall structure as well as the underlying organization of the protein-protein interactions. The interaction network described here is comprised of 778 nodes and 1943 edges and has a scale-free topology. Rac1, Cdc42, RhoA, and HRas are identified as the hubs. Ten sub-network motifs are also identified in this study with themes in apoptosis, cell growth/proliferation, vesicle traffic, cell adhesion/junction dynamics, the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase response, transcription regulation, receptor-mediated endocytosis, gene silencing, and growth factor signaling. Bottleneck proteins that bridge signaling paths and proteins that overlap in multiple small GTPase networks are described along with the functional annotation of all proteins in the network.

New insights in flat oyster Ostrea edulis resistance against the parasite Bonamia ostreae

Bonamiosis due to the parasite Bonamia ostreae has been associated with massive mortality in flat oyster stocks in Europe. Control of the disease currently relies on disease management practices and transfer restriction. Previously, massal selections based on survival to challenge to infection with B. ostreae have been applied to produce flat oyster families with resistant progeny. In an attempt to understand the molecular mechanisms involved in disease resistance, differentially expressed sequence tags between resistant and wild Ostrea edulis haemocytes, both infected with the parasite, were identified using suppression subtractive hybridisation. Expression of seven ESTs has been studied using quantitative reverse-transcriptase PCR. The base-line expression of an extracellular superoxide dismutase, inhibitor of apoptosis (OeIAP), Fas ligand (OeFas-ligand) and Cathepsin B was significantly increased, whilst cyclophilin B appeared significantly decreased in resistant oysters. Considering their great interest for further studies, the open reading frames of the OeFas-ligand and OeIAP were completely sequenced.

Fas signaling promotes motility and metastasis through epithelial-mesenchymal transition in gastrointestinal cancer

Fas signaling was reported to participate in cell apoptosis. However, this pathway has also been shown to promote tumor cell motility, leading to the hypothesis that Fas signaling may induce epithelial-mesenchymal transition (EMT) to promote metastasis. The effects of Fas-ligand (FasL) treatment and inhibition of Fas signaling on colorectal and gastric cancer cells were tested using motility assay, immunofluorescence, RT-PCR and immunoblot analyses. Fas signaling downregulated epithelial markers, upregulated mesenchymal markers and promoted motility in gastrointestinal (GI) cancer cells. FasL treatment also increased the expression of EMT transcriptional factors in the nucleus and induced a spindle shape cell morphology in these cells. Knockdown of Snail or Twist expression significantly decreased FasL-induced motility. The ERK1/2 pathway was activated by Fas signaling and is required for FasL-induced EMT and motility. Moreover, oxaliplatin, a chemotherapeutic agent, induced EMT partly through Fas signaling. Evaluation of human GI clinical specimens showed that FasL expression increased whereas E-cadherin expression decreased during GI cancer progression. Both markers were significantly inversely correlated. Tissue samples with a non-EMT phenotype were mainly distributed in patients with early cancer stages, whereas samples with an EMT phenotype were mostly distributed in patients with advanced cancer stages. A non-EMT phenotype significantly correlated with better prognosis. Altogether, these data indicate that Fas signaling may induce EMT to promote tumor motility and metastasis in GI cancer in vivo and in vitro.

Effect of granulocyte-colony stimulating factor on expression of selected proteins involved in regulation of apoptosis in the brain of newborn piglets after cardiopulmonary bypass and deep hypothermic circulatory arrest

OBJECTIVE

The study objective was to investigate the effect of granulocyte-colony stimulating factor on the expression of proteins that regulate apoptosis in newborn piglet brain after cardiopulmonary bypass and deep hypothermic circulatory arrest.

METHODS

The newborn piglets were assigned to 3 groups: (1) deep hypothermic circulatory arrest (30 minutes of deep hypothermic circulatory arrest, 1 hour of low-flow cardiopulmonary bypass); (2) deep hypothermic circulatory arrest with prior injection of granulocyte-colony stimulating factor (17 μg/kg 2 hours before cardiopulmonary bypass); and (3) sham-operated. After 2 hours of post-bypass recovery, the frontal cortex, striatum, and hippocampus were dissected. The expression of proteins was measured by gel electrophoresis or protein arrays. Data are presented in arbitrary units. Statistical analysis was performed using 1-way analysis of variance.

RESULTS

In the frontal cortex, only Fas ligand expression was significantly lower in the granulocyte-colony stimulating factor group when compared with the deep hypothermic circulatory arrest group. In the hippocampus, granulocyte-colony stimulating factor increased Bcl-2 (54.3 ± 6.4 vs 32.3 ± 2.2, P = .001) and serine/threonine-specific protein kinase (141.4 ± 19 vs 95.9 ± 21.1, P = .047) when compared with deep hypothermic circulatory arrest group. Caspase-3, Bax, Fas, Fas ligand, death receptor 6, and Janus protein tyrosine kinase 2 levels were unchanged. The Bcl-2/Bax ratio was 0.33 for deep hypothermic circulatory arrest group and 0.93 for the granulocyte-colony stimulating factor group (P = .02). In the striatum, when compared with the deep hypothermic circulatory arrest group, the granulocyte-colony stimulating factor group had higher levels of Bcl-2 (50.3 ± 7.4 vs 31.8 ± 3.8, P = .01), serine/threonine-specific protein kinase (132.7 ± 12.3 vs 14 ± 1.34, P = 2.3 × 10(6)), and Janus protein tyrosine kinase 2 (126 ± 17.4 vs 77.9 ± 13.6, P = .011), and lower levels of caspase-3 (12.8 ± 5.0 vs 32.2 ± 11.5, P = .033), Fas (390 ± 31 vs 581 ± 74, P = .038), Fas ligand (20.5 ± 11.5 vs 57.8 ± 15.6, P = .04), and death receptor 6 (57.4 ± 4.4 vs 108.8 ± 13.4, P = .007). The Bcl-2/Bax ratio was 0.25 for deep hypothermic circulatory arrest and 0.44 for the granulocyte-colony stimulating factor groups (P = .046).

CONCLUSIONS

In the piglet model of hypoxic brain injury, granulocyte-colony stimulating factor decreases proapoptotic signaling, particularly in the striatum.