Fas-dependent Pathways Research Articles

Diosgenin Attenuates Myocardial Cell Apoptosis Triggered by Oxidative Stress through Estrogen Receptor to Activate the PI3K/Akt and ERK Axes.

Cardiovascular diseases in post-menopausal women are on a rise. Oxidative stress is the main contributing factor to the etiology and pathogenesis of cardiovascular diseases. Diosgenin, a member of steroidal sapogenin, is structurally similar to estrogen and has been shown to have antioxidant effects. Therefore, we aimed to investigate the effects of diosgenin in preventing oxidation-induced cardiomyocyte apoptosis and assessed its potential as a substitute substance for estrogen in post-menopausal women. Apoptotic pathways and mitochondrial membrane potential were measured in H9c2 cardiomyoblast cells and neonatal cardiomyocytes treated with diosgenin for 1[Formula: see text]h prior to hydrogen peroxide (H2O2) stimulation. H2O2-stimulated H9c2 cardiomyoblast cells displayed cytotoxicity and apoptosis via the activation of both Fas-dependent and mitochondria-dependent pathways. Additionally, it led to the instability of the mitochondrial membrane potential. However, the H2O2-induced H9c2 cell apoptosis was rescued by diosgenin through IGF1 survival pathway activation. This led to the recovery of the mitochondrial membrane potential by suppressing the Fas-dependent and mitochondria-dependent apoptosis. Diosgenin also inhibited H2O2-induced cytotoxicity and apoptosis through the estrogen receptor interaction with PI3K/Akt and extracellular regulated protein kinases 1/2 activation in myocardial cells. In this study, we confirmed that diosgenin attenuated H2O2-induced cytotoxicity and apoptosis through estrogen receptors-activated phosphorylation of PI3K/Akt and ERK signaling pathways in myocardial cells via estrogen receptor interaction. All results suggest that H2O2-induced myocardial damage is reduced by diosgenin due to its interaction with estrogen receptors to decrease the damage. Herein, we conclude that diosgenin might be a potential substitute substance for estrogen in post-menopausal women to prevent heart diseases.

Hyperglycemia-Induced Cardiac Damage Is Alleviated by Heat-Inactivated Lactobacillus reuteri GMNL-263 via Activation of the IGF1R Survival Pathway.

Diabetes-induced cardiomyocyte apoptosis is one of the major causes of mortality in patients with diabetes. Numerous studies have indicated the beneficial effects of Lactobacillus reuteri GMNL-263. However, the protective effect of Lactobacillus reuteri GMNL-263 in cardiac damage associated with diabetes remains poorly understood. In this study, we aimed to investigate the protective effect of Lactobacillus reuteri GMNL-263 on cardiomyocytes in diabetic rats. Five-week-old male Wistar rats were categorized into normal control group, diabetes group (55mg/kgw STZ-induced diabetes via intraperitoneal injection), and diabetic animals treated with Lactobacillus reuteri GMNL-263 (109CFU/rat/day, oral administration for 4weeks). The results were presented that oral administration of a high dose of Lactobacillus reuteri GMNL-263 in diabetic rats activated IGF1R cell survival pathways to decrease the Fas-dependent and mitochondrial-dependent apoptotic pathways induced by hyperglycemia. We found that GMNL-263 significantly attenuated cell apoptosis via the IGF1R survival pathway in diabetic rats. The findings of this study suggest that GMNL-263 treatment maybe an effective therapeutic approach for the prevention of cardiac apoptosis in patients with diabetes.

Activity Mapping the Acyl Carrier Protein: Elongating Ketosynthase Interaction in Fatty Acid Biosynthesis.

Elongating ketosynthases (KSs) catalyze carbon-carbon bond-forming reactions during the committed step for each round of chain extension in both fatty acid synthases (FASs) and polyketide synthases (PKSs). A small α-helical acyl carrier protein (ACP) shuttles fatty acyl intermediates between enzyme active sites. To accomplish this task, the ACP relies on a series of dynamic interactions with multiple partner enzymes of FAS and associated FAS-dependent pathways. Recent structures of the Escherichia coli FAS ACP, AcpP, in covalent complexes with its two cognate elongating KSs, FabF and FabB, provide high-resolution details of these interfaces, but a systematic analysis of specific interfacial interactions responsible for stabilizing these complexes has not yet been undertaken. Here, we use site-directed mutagenesis with both in vitro and in vivo activity analyses to quantitatively evaluate these contacting surfaces between AcpP and FabF. We delineate the FabF interface into three interacting regions and demonstrate the effects of point mutants, double mutants, and region deletion variants. Results from these analyses reveal a robust and modular FabF interface capable of tolerating seemingly critical interface mutations with only the deletion of an entire region significantly compromising activity. Structure and sequence analyses of FabF orthologs from related type II FAS pathways indicate significant conservation of type II FAS KS interface residues and, overall, support its delineation into interaction regions. These findings strengthen our mechanistic understanding of molecular recognition events between ACPs and FAS enzymes and provide a blueprint for engineering ACP-dependent biosynthetic pathways.

ʟ-Arginine Inhibits Apoptosis of Ovine Intestinal Epithelial Cells through the ʟ-Arginine–Nitric Oxide Pathway

In nonruminants, many of the biological roles of l-arginine (Arg) at the intestinal level are mediated through the Arg-nitric oxide (Arg-NO) pathway. Whether the Arg-NO pathway is involved in controlling the immune response and viability in ovine intestinal epithelial cells (IOECs) is unclear. The current study aimed to examine the role of the Arg-NO pathway in apoptosis, antioxidant capacity, and mitochondrial function of IOECs. The IOECs were incubated in Arg-free DMEM supplemented with 150μM Arg (CON) or 300μM Arg (ARG) alone or with 350μM Nw-nitro-l-arginine methyl ester hydrochloride (l-NAME) (CON+NAME, ARG+NAME) for 24h. The reactive oxygen species (ROS) concentration, antioxidant capacity, and cell apoptotic percentage were determined. Arg supplementation decreased (P <0.05) the ROS concentration (38.9% and 22.7%) and apoptotic cell percentage (57.2% and 54.8%) relative to the CON and CON+NAME groups, respectively. Relative to the CON and ARG treatments, the l-NAME administration decreased (P <0.05) the mRNA abundance of superoxide dismutase 2 (32% and 21.3%, respectively) and epithelial NO synthase (36% and 29.1%, respectively). Arg supplementation decreased (P <0.05) the protein abundance of apoptosis antigen 1 (FAS) (52.0% and 43.9%) but increased (P <0.05) those of nuclear respiratory factor 1 (31.3% and 22.9%) and inducible NO synthase (35.2% and 41.8%) relative to the CON and CON+NAME groups, respectively. The inhibition of apoptosis in IOECs due to the increased supply of Arg is associated with the mitochondria- and FAS-dependent pathways through the activity of the Arg-NO pathway. The findings help elucidate the role of the Arg-NO pathway in IOEC growth and apoptosis.

Swimming exercise stimulates IGF1/ PI3K/Akt and AMPK/SIRT1/PGC1α survival signaling to suppress apoptosis and inflammation in aging hippocampus.

Hippocampus is one of the most vulnerable brain regions in terms of age-related pathological change. Exercise is presumed to delay the aging process and promote health because it seems to improve the function of most of the aging mechanisms. The purpose of this study is to evaluate the effects of swimming exercise training on brain inflammation, apoptotic and survival pathways in the hippocampus of D-galactose-induced aging in SD rats. The rats were allocated to the following groups: (1) control; (2) swimming exercise; (3) induced-aging by injecting D-galactose; (4) induced-aging rats with swimming exercise. The longevity-related AMPK/SIRT1/PGC-1α signaling pathway and brain IGF1/PI3K/Akt survival pathway were significantly reduced in D-galactose-induced aging group compared to non-aging control group and increased after exercise training. The inflammation pathway markers were over-expressed in induced-aging hippocampus, exercise significantly inhibited the inflammatory signaling activity. Fas-dependent and mitochondrial-dependent apoptotic pathways were significantly increased in the induced-aging group relative to the control group whereas they were decreased in the aging-exercise group. This study demonstrated that swimming exercise not only reduced aging-induced brain apoptosis and inflammatory signaling activity, but also enhanced the survival pathways in the hippocampus, which provides one of the new beneficial effects for exercise training in aging brain.

Neuroprotective Effect of Rhodiola crenulata in D-Galactose-Induced Aging Model.

The medicinal plant Rhodiola crenulata grows at high altitudes in the Arctic and mountainous regions and is commonly used in phytotherapy in Eastern European and Asian countries. In the present study, we investigated the anti-apoptotic effect of Rhodiola crenulata and its neuroprotective mechanism of action in a rat model of D-galactose-induced aging. Two groups of twelve-week-old male Wistar rats received a daily injection of D-galactose (150mg/kg/day, i.p.) and orally administered Rhodiola crenulata (0, 248mg/kg/day) for eight weeks, while a control group received a saline injection (1ml/kg/day, i.p.). We examined apoptosis in the cortex and hippocampus of three groups of rats based on a terminal deoxynucleotide transferase-mediated deoxy uridine triphosphate nick-end labeling (TUNEL) positive assay. The expression levels of apoptotic and anti-apoptotic proteins in excised brains were analyzed by Western blotting. Our findings indicated that D-galactose caused marked neuronal apoptosis via activation of both extrinsic-dependent and mitochondrial-dependent apoptotic pathways. When compared to the control group, the protein levels of Fas receptor, Fas ligand, Fas-associated death domain (FADD), and activated caspase-8 (Fas-dependent apoptotic pathways), as well as those of t-Bid, Bax, cytochrome , activated caspase-9, and activated caspase-3 (mitochondrial-dependent apoptotic pathways), were significantly increased in the D-galactose treated group. In addition, D-galactose impaired the phosphorylation of PI3K/Akt, an important survival signaling event in neurons. Rhodiola crenulata, however, protected against all these neurotoxicities in aging brains. The present study suggests that neuronal survival promoted by Rhodiola crenulata may be a potentially effective method to enhance the resistance of neurons to age-related disorders.

Anti-Apoptotic Effects of Diosgenin in D-Galactose-Induced Aging Brain.

The purpose of this study was to evaluate the effects of diosgenin on the D-galactose-induced cerebral cortical widely dispersed apoptosis. Male 12-week-old Wistar rats were divided into four groups: Control (1mg/kg/day of saline, i.p.), DD0 (150mg/kg/day of D-galactose, i.p.), DD10, and DD50 (D-galactose or 50mg/kg/day of diosgenin orally). After eight weeks, histopathological analysis, positive TUNEL and Western blotting assays were performed on the excised cerebral cortex from all four groups. The TUNEL-positive apoptotic cells, the components of Fas pathway (Fas, FADD, active caspase-8 and active caspase-3), and mitochondria pathway (t-Bid, Bax, cytochrome , active caspase-9 and active caspase-3) were increased in the DD0 group compared with the control group, whereas they were decreased in the DD50 group. The components of survival pathway (p-Bad, Bcl-2, Bcl-xL, IGF-1, p-PI3K and p-AKT) were increased in the DD50 group compared to the control group, whereas the levels of Bcl-xL, p-PI3K, and p-AKT were also compensatorily increased in the DD0 group compared to the control group. Taken together, diosgenin suppressed D-galactose-induced neuronal Fas-dependent and mitochondria-dependent apoptotic pathways and enhanced the Bcl-2 family associated pro-survival and IGF-1-PI3K-AKT survival pathways, which might provide neuroprotective effects of diosgenin for prevention of the D-galactose-induced aging brain.

Adenoviral vaccine induction of CD8+ T cell memory inflation: Impact of co-infection and infection order.

The efficacies of many new T cell vaccines rely on generating large populations of long-lived pathogen-specific effector memory CD8 T cells. However, it is now increasingly recognized that prior infection history impacts on the host immune response. Additionally, the order in which these infections are acquired could have a major effect. Exploiting the ability to generate large sustained effector memory (i.e. inflationary) T cell populations from murine cytomegalovirus (MCMV) and human Adenovirus-subtype (AdHu5) 5-beta-galactosidase (Ad-lacZ) vector, the impact of new infections on pre-existing memory and the capacity of the host’s memory compartment to accommodate multiple inflationary populations from unrelated pathogens was investigated in a murine model. Simultaneous and sequential infections, first with MCMV followed by Ad-lacZ, generated inflationary populations towards both viruses with similar kinetics and magnitude to mono-infected groups. However, in Ad-lacZ immune mice, subsequent acute MCMV infection led to a rapid decline of the pre-existing Ad-LacZ-specific inflating population, associated with bystander activation of Fas-dependent apoptotic pathways. However, responses were maintained long-term and boosting with Ad-lacZ led to rapid re-expansion of the inflating population. These data indicate firstly that multiple specificities of inflating memory cells can be acquired at different times and stably co-exist. Some acute infections may also deplete pre-existing memory populations, thus revealing the importance of the order of infection acquisition. Importantly, immunization with an AdHu5 vector did not alter the size of the pre-existing memory. These phenomena are relevant to the development of adenoviral vectors as novel vaccination strategies for diverse infections and cancers. (241 words)

Mincle inhibits neutrophils and macrophages apoptosis in A. fumigatus keratitis

PurposeTo determine whether macrophage inducible C-type lectin (Mincle) regulates neutrophils and macrophages apoptosis in A. fumigatus keratitis. Materials and methodsA murine model (C57BL/6) of fungal keratitis (AF) was established by gently scraping corneal central epithelium, smearing A. fumigatus on the epithelium surface and covering the eye with contact lenses. AF cell model was established by extracting neutrophils (PMN) and macrophages, and then infecting cells with A. fumigatus. Animals and cells were randomly divided into control and A. fumigatus keratitis group, which were treated with Mincle ligand Trehalose-6,6-dibehenate (TDB), Mincle neutralizing antibody (MincleAb) or PBS before infection. The cornea infection was monitored using a slit lamp and further analyzed using H&E assay. PCR, Western blot, immunostaining, TUNEL staining and flow cytometry were used to examine the expression of Mincle and apoptosis factors, PMN infiltration and cell apoptosis, respectively. ResultsHigher levels of Mincle mRNA and protein, as well as epithelial thickness and presence of inflammatory cells in the stroma, were observed in the AF group compared to control. In addition, higher Mincle mRNA levels were observed in normal and stimulated neutrophils and macrophages. Furthermore, Fas, FasL and CASP3 mRNA levels, neutrophils infiltration rate and TUNEL-positive cells were significantly increased in AF+MincleAb mice compared with the control. Similar results, as well as significantly higher neutrophils and macrophages apoptosis, were observed by treating cells with MincleAb in vitro. Most importantly, opposite results i.e. lower mRNA levels, neutrophils infiltration rate and TUNEL-positive cells, as well as lower cell apoptosis in vitro, were observed in mice and cells treated with TDB. ConclusionMincle-participated in inflammatory process which inhibits neutrophils and macrophages apoptosis induced by A. fumigatus involved in Fas-dependent apoptotic pathways.

Myocardial oxidative damage is induced by cardiac Fas-dependent and mitochondria-dependent apoptotic pathways in human cocaine-related overdose

The aim of this study is to analyse cardiac specimens from human cocaine-related overdose, to verify the hypothesis that cardiac toxicity by acute exposure to high dosage of cocaine could be mediated by unbalanced myocardial oxidative stress, and to evaluate the apoptotic response. To address these issues, biochemical and immunohistological markers of oxidative/nitrosative stress were evaluated. We found that i-NOS, NOX2 and nitrotyrosine expression were significantly higher in the hearts of subjects who had died from high doses of cocaine, compared to the control group. Increase of these markers was associated with a dramatic increase in 8-OHdG, another marker of oxidative stress. A high number of TUNEL-positive apoptotic myocells was observed in the study group compared to the control group. The immunoexpression of TNF-α was significantly higher in the cocaine group compared to the control group. Furthermore, we detected a significantly stronger immunoresponse to anti-SMAC/DIABLO in our study group compared to control cases. Both cardiac Fas-dependent and mitochondria-dependent apoptotic pathways appeared to be activated to a greater extent in the cocaine group than in the control group. Our results highlight the central role of oxidative stress in cocaine toxicity. High levels of NOS can promote the oxidation process and lead to apoptosis.

Therapeutic effects of Dioscorea on post-menopause-induced cardiac apoptosis in rats.

To evaluate the effects of Dioscorea on bilateral ovariectomies-induced cardiac Fasdependent and mitochondria-dependent apoptotic pathways. Forty-eight female Wistar rats at 6-7 months of age were equally divided into a sham-operated group, and a bilateral ovariectomized (OVX) group for 2 months, and the rats in the OVX group were further fed with 0, 250 or 750 mL/kg Dioscorea spp. daily in the 2nd month. The excised hearts were measured by positive terminal deoxynucleotidyltransferase UTP nick end labeling (TUNEL) assays, western blotting and reverse transcription-polymerase chain reaction. Dioscorea spp. decreased OVX-induced cardiac TUNEL-positive apoptotic cells; decreased OVX-induced TNF-alpha, Fas ligand, Fas death receptors, Fas-associated death domain, activated caspase-8, and -3 (Fas pathways); decreased OVX-induced Bad, Bax, Bax-to-Bcl2 ratio, activated caspase-9, and -3 (mitochondria pathway). Dioscorea spp. prevented ovariectomy-induced cardiac Fas-dependent and mitochondriadependent apoptotic pathways in rat models. The fifi ndings may provide possible therapeutic effects of dioscorea for potentially preventing cardiac apoptosis after ovariectomy or post-menopause.

Fas Role in Ischemic Stroke: Not Only in Apoptosis

The receptors, whose ligand interaction activation was previously considered to be associated with initiation of apoptosis only, can have a range of biological effects: apoptosis, inflammation, proliferation, and differentiation. Therefore, interaction between death receptor and its ligand does not always mean the initiation of programmed cell death and blocking of this ligand-receptor interaction can affect the initiation of recovery and neuroplasticity mechanisms. Fas is one of these death receptors. The following review represents data on the conditions of Fasdependent signal pathways induction in ischemic stroke. There is a possibility for the development of new target neuroprotective drugs with selective effects on different separated signal pathways, activated by ligand-receptor interactions in Fas-FasL (Fas ligand) system.

Whole-Exome Analysis of Autoimmune Lymphoproliferative Syndrome-like Diseases

ALPS is characterized by chronic lymphoproliferation in combination with autoimmunity; mutations of molecules involved in FAS-dependent pathways play causative roles in this syndrome. The hallmarks of ALPS are an elevated CD4/CD8 double-negative T (DNT) cell count and attenuated induction of apoptosis by FAS stimulation. Autoimmune thrombocytopenia and/or hemolytic anemia are common in cases of ALPS; the combination of autoimmune thrombocytopenia and hemolytic anemia is referred to as Evans syndrome. ALPS is diagnosed in 47% of patients who present with Evans syndrome. Some patients with ALPS-like syndromes harbor mutations in RAS or PRKCD.In this study, we performed whole-exome analysis of undiagnosed patients exhibiting autoimmunity in combination with lymphoproliferation. Fifteen pediatric patients presenting with autoimmunity were enrolled in this study. Although not all of them fulfilled the diagnostic criteria of ALPS, most of them exhibited an ALPS-like phenotype, an autoimmune hematological disorder such as Evans syndrome, or immune thrombocytopenia with hepatosplenomegaly. Elevated counts of DNT cells among TCRαβ-positive cells were observed in some cases. All of the subjects screened negative for mutations in FAS, FASL, KRAS, and NRAS. These patients were subjected to whole-exome analysis, which revealed several mutations with known disease associations. One patient carried a mutation in CASP10, a causative gene for ALPS-CSAP (ALPS 2). This patient exhibited a typical ALPS phenotype with an elevated DNT cell count. In addition, we identified CTLA4 mutations in two patients, one of whom was described as ALPS type V (ALPS 5) and the other as CTLA4 haploinsufficiency with autoimmune infiltration (CHAI). A mutation in STAT3 was present in one patient. Dominant-negative mutations in the STAT3 gene result in hyper-IgE syndrome. Recently, an activating mutation of STAT3 was reported in infantile-onset multisystem autoimmune disease (ADMIO). It should be noted that an activating mutation of STAT3 results in a phenotype very similar to that of ALPS. Intriguingly, two autoinflammatory associated genes, PSTPIP1 and RNASEH2B were identified. Mutations in RNASEH2B causes Aicardi-Goutière syndrome (AGS), which phenotypically overlaps with SLE. Typical AGS develops as a results of biallelic mutations in causative genes. In this case, a heterozygous frame shift mutation was identified. Further evaluation is required to confirm whether this heterozygous frame shift mutation RNASEH2B really causes SLE or ALPS like symptoms. PSTPIP1 mutation causes pyogenic Arthritis, pyoderma gangrenosum and acne (PAPA) syndrome. The identified E250K mutation was one of the typical mutation in this disease. This patient exhibited SLE like symptom with hepatosplenomegaly without typical PAPA syndrome like symptoms, such as acne or pyoderma of the skin. Sequencing of the remaining patients yielded inconclusive results.The classical ALPS diagnostic procedure is well designed and suitable for identification of FAS-dependent apoptotic dysregulation. However, the measurement of FAS-dependent apoptosis requires technical skill, and the data quality is therefore dependent on the investigator. Moreover, RAS-associated ALPS-like disease (RALD, ALPS 3) and ALPS 5 (CHAI) cannot be identified by conventional ALPS diagnostic procedures. Therefore, the methods for diagnostic classification of these diseases need to be updated. It is interesting that mutations of autoinflammatory associated genes are involved in ALPS or SLE like patients. Our results reveal that a comprehensive genomic approach is a powerful tool for the characterization of ALPS or ALPS-like diseases. Together with recent progress in genome analysis in the PID field, our analyses provide an updated list of genes for use in differential diagnosis of ALPS-like diseases. This update will facilitate convenient genomic approaches such as comprehensive targeted sequencing focusing on genes involved in ALPS or ALPS-like diseases. This approach can be directly applied in the clinic to yield diagnostic benefits. DisclosuresNo relevant conflicts of interest to declare.

Effects of rhodiola crenulata on mice hearts under severe sleep apnea.

BackgroundThe goal of this study is to determine if Rhodiola Crenulata (RC) has protective effects on mice hearts with severe sleep apnea model.MethodsSixty-four C57BL/6 J mice 5–6 months old were distributed into 4 groups i.e. Control group (21 % O2, 24 h per day, 8 weeks, n = 16); Hypoxia group (Hypoxia: 7 % O2 60 s, 20 % O2 alternating 60 s, 8 h per day, 8 weeks, n = 16); Hypoxia + 90RC and Hypoxia + 270RC group (Hypoxia for 1st 4 weeks and hypoxia pretreated 90 mg/Kg and 270 mg/Kg Rhodiola Crenulata by oral gavage per day for 2nd 4 weeks, each n = 16). Excised hearts from 4 groups of mice were analyzed for heart weight index changes using H&E staining, TUNEL-positive assays and Western Blotting protein.ResultsCardiac widely dispersed TUNEL-positive apoptotic cells in mice hearts were less in Hypoxia + RC90 and Hypoxia + RC270 than those in Hypoxia. Compared with Hypoxia, the protein levels of Fas ligand, Fas death receptors, Fas-Associated Death Domain (FADD), activated caspase 8, and activated caspase 3 (Fas dependent apoptotic pathways) were decreased in Hypoxia + RC90, Hypoxia + RC270. The protein levels of Bad, Bax, t-Bid, activated caspase 9, activated caspase 3 (mitochondria dependent apoptotic pathway) were less in Hypoxia + RC90, Hypoxia + RC270 than those in hypoxia. The protein levels of Bcl2, Bcl-xL, p-Bad (Bcl2-realted anti-apoptotic pathway) and VEGF, p-PI3k, p-AKT (VEGF-related pro-survival pathway) were higher in Hypoxia + RC90, Hypoxia + RC270 than those in hypoxia.ConclusionsOur findings suggest that Rhodiola Crenulata have protective effects on chronic intermittent hypoxia-induced cardiac widely dispersed apoptosis via Fas-dependent and mitochondria-dependent apoptotic and VEGF-related pro-survival pathway.

Protective Effect Of Irbesartan(arb) On Cortical Apoptosis In Rat With Chronic Intermittent Hypoxia Model

Chronic intermittent hypoxia could lead to cerebral cellular apoptosis and necrosis. PURPOSE:The present study was to evalute the protective effect of irbesartan on cortical apoptosis in sleep apnea rat model. METHODS: Cortical apoptosis and apoptotic pathways were measured by TUNEL and Western blotting in twenty-four SD rats which were divided into three groups, rats with normoxic exposure (Control), normoxia 21% O2 and rats with chronic intermittent hypoxia (HYPOXIA, 3-7% O2 versus 21% O2 per 40 seconds cycle, 8 hrs per day for a month), and subcutaneous treatment with irbesartan (HYPOXIA+ARB, 50 mg/kg, s.c.) under chronic intermittent hypoxia (HYPOXIA+ARB) at 5-6 months of age. RESULTS: The protein levels of Fas ligand, Fas death receptors, Fas-Associated Death Domain (FADD), activated caspase 8, and activated caspase 3 (Fas pathways), were increased in HYPOXIA relative to Control, which were decreased in HYPOXIA+ARB compared with HYPOXIA. CONCLUSION: Our findings suggest that irbesartan has protective effects on chronic intermittent hypoxia-induced Fas-dependent apoptotic pathways in rat cerebral cortex.

Cardiac Fas-Dependent and Mitochondria-Dependent Apoptotic Pathways in a Transgenic Mouse Model of Huntington's Disease.

Huntington's disease is an autosomal dominant neurodegenerative disease caused by a CAG repeat expansion in the huntingtin gene. Heart disease is the second leading cause of death in patients with Huntington's disease. This study was to evaluate whether cardiac Fas-dependent and mitochondria-dependent apoptotic pathways are activated in transgenic mice with Huntington's disease. Sixteen Huntington's disease transgenic mice (HD) and sixteen wild-type (WT) littermates were studied at 10.5weeks of age. The cardiac characteristics, myocardial architecture, and two major apoptotic pathways in the excised left ventricle from mice were measured by histopathological analysis, Western blotting, and TUNEL assays. The whole heart weight and the left ventricular weight decreased significantly in the HD group, as compared to the WT group. Abnormal myocardial architecture, enlarged interstitial spaces, and more cardiac TUNEL-positive cells were observed in the HD group. The key components of Fas-dependent apoptosis (TNF-alpha, TNFR1, Fas ligand, Fas death receptors, FADD, activated caspase-8, and activated caspase-3) and the key components of mitochondria-dependent apoptosis (Bax, Bax-to-Bcl-2 ratio, cytosolic cytochrome c, activated caspase-9, and activated caspase-3) increased significantly in the hearts of the HD group. Cardiac Fas-dependent and mitochondria-dependent apoptotic pathways were activated in transgenic mice with Huntington's disease, which might provide one of possible mechanisms to explain why patients with Huntington's disease will develop heart failure.

Protective effect of salidroside on cardiac apoptosis in mice with chronic intermittent hypoxia

BackgroundThe goal of this study is to determine if salidroside has protective effects on hypoxia-induced cardiac widely dispersed apoptosis in mice with severe sleep apnea model. MethodsSixty-four C57BL/6J mice 5–6months of age were divided into four groups, i.e. Control group (21% O2, 24h per day, 8weeks, n=16); Hypoxia group (Hypoxia: 7% O2 60s, 20% O2 alternating 60s, 8h per day, 8weeks, n=16); and Hypoxia+S10 and Hypoxia+S30 groups (Hypoxia for 1st 4weeks, hypoxia pretreated 10mg/kg and 30mg/kg salidroside by oral gavage per day for 2nd 4weeks, n=16 and 16). The excised hearts from four groups were measured by the heart weight index, H&E staining, TUNEL-positive assays and Western blotting. ResultsTUNEL-positive apoptotic cells in mice heart were less in Hypoxia+S10 and Hypoxia+S30 than those in the Hypoxia group. Compared with Hypoxia, the protein levels of Fas ligand, Fas death receptors, Fas-Associated Death Domain (FADD), activated caspase 8, and activated caspase 3 (Fas pathways) were decreased in Hypoxia+S10 and Hypoxia+S30. In the mitochondria pathway, the protein levels of BcLx, Bcl2, and Bid (anti-apoptotic Bcl2 family) in Hypoxia+S10 and Hypoxia+S30 were more than those in Hypoxia. The protein levels of Bax, t-Bid, activated caspase 9, and activated caspase 3 were less in Hypoxia+S10 and Hypoxia+S30 than those in hypoxia. ConclusionsOur findings suggest that salidroside has protective effects on chronic intermittent hypoxia-induced Fas-dependent and mitochondria-dependent apoptotic pathways in mice hearts.

Cardiac Fas-dependent and mitochondria-dependent apoptosis after chronic cocaine abuse.

To evaluate whether chronic cocaine abuse will increase cardiac Fas-dependent and mitochondria-dependent apoptotic pathways, thirty-two male Wistar rats at 3–4 months of age were randomly divided into a vehicle-treated group (phosphate-buffered saline, PBS, 0.5 mL, SQ per day) and a cocaine-treated group (Cocaine, 10 mg/kg, SQ per day). After 3 months of treatment, the excised left ventricles were measured by H&E staining, Western blotting, DAPI staining and TUNEL assays. More cardiac TUNEL-positive apoptotic cells were observed in the Cocaine group than the PBS group. Protein levels of TNF-alpha, Fas ligand, Fas death receptor, FADD, activated caspase-8, and activated caspase-3 (Fas-dependent apoptosis) extracted from excised hearts in the Cocaine group were significantly increased, compared to the PBS group. Protein levels of cardiac Bax, cytosolic cytochrome c, t-Bid-to-Bid, Bak-to-Bcl-xL, Bax-to-Bcl-2 ratio, activated caspase-9, and activated caspase-3 (mitochondria-dependent apoptosis) were significantly increased in the Cocaine group, compared to the PBS group. Chronic cocaine exposure appeared to activate the cardiac Fas-dependent and mitochondria-dependent apoptosis, which may indicate a possible mechanism for the development of cardiac abnormalities in humans with chronic cocaine abuse.

Anti-apoptotic and pro-survival effect of protocatechuic acid on hypertensive hearts

Cardiac apoptosis was found in hearts from hypertensive animals, therefore in this study we aimed to evaluate the anti-apoptotic and pro-survival effects of protocatechuic acid (PCA) on hypertensive hearts. At first we found that, sedentary group (SHR)-PCA group’s decreased TUNEL-positive apoptotic cells than SHR group alone. Protein levels of Fas ligand, Fas death receptor, Fas-associated death domain (FADD), Bid, t-Bid, Bax, cytochrome c, activated caspase-8, activated caspase 9 and activated caspase-3 were decreased in SHR-PCA group compared with SHR group. Moreover, SHR-PCA groups increased pro-survival pathway proteins like IGF1, pIGF1R, pPI3K, p-Akt, Bcl-xL, and Bcl-2 than SHR and sedentary normotensive group (WKY). All these finding suggest us that, Protocatechuic acid prevented hypertension-enhanced cardiac Fas-dependent and mitochondria-dependent apoptotic pathways and enhanced cardiac pro-survival pathway in rat models.

Chronic Methamphetamine Exposure Induces Cardiac Fas-Dependent and Mitochondria-Dependent Apoptosis

Very limited information regarding the influence of chronic methamphetamine exposure on cardiac apoptosis is available. In this study, we evaluate whether chronic methamphetamine exposure will increase cardiac Fas-dependent (type I) and mitochondria-dependent (type II) apoptotic pathways. Thirty-two male Wistar rats at 3-4 months of age were randomly divided into a vehicle-treated group [phosphate-buffered saline (PBS) 0.5 ml SQ per day] and a methamphetamine-treated group (MA 10 mg/kg SQ per day) for 3 months. We report that after 3 months of exposure, abnormal myocardial architecture, more minor cardiac fibrosis and cardiac TUNEL-positive apoptotic cells were observed at greater frequency in the MA group than in the PBS group. Protein levels of TNF-α, Fas ligand, Fas receptor, Fas-associated death domain, activated caspase-8, and activated caspase-3 (Fas-dependent apoptosis) extracted from excised hearts were significantly increased in the MA group, compared to the PBS group. Protein levels of cardiac Bak, t-Bid, Bak to Bcl-xL ratio, activated caspase-9, and activated caspase-3 (mitochondria-dependent apoptosis) were significantly increased in the MA group, compared with the PBS group. The results from this study reveal that chronic methamphetamine exposure will activate cardiac Fas-dependent and mitochondria-dependent apoptotic pathways, which may indicate a possible mechanism for developing cardiac abnormalities in humans with chronic methamphetamine abuse.