Inhibition of Intracellular Type 10 Adenylyl Cyclase Protects Cortical Neurons Against Reperfusion-Induced Mitochondrial Injury and Apoptosis.

Mitochondrial injury significantly contributes to the neuronal death under cerebral ischemia and reperfusion. Within several signaling pathways, cyclic adenosine monophosphate (cAMP) signaling plays a substantial role in mitochondrial injury and cell death. Traditionally, the source of cellular cAMP has been attributed to the membrane-bound adenylyl cyclase, whereas the role of the intracellular localized type 10 soluble adenylyl cyclase (sAC) in neuronal pathology has not been considered. Since neurons express an active form of sAC, we aimed to investigate the role of sAC in reperfusion-induced neuronal apoptosis. For this purpose, the in vitro model of oxygen/glucose deprivation (simulated ischemia, 1 h), followed by recovery (simulated reperfusion, 12 h) in rat embryonic neurons, was applied. Although ischemia alone had no significant effect on apoptosis, reperfusion led to an activation of the mitochondrial pathway of apoptosis, hallmarked by mitochondrial depolarization, cytochrome c release, and mitochondrial ROS formation. These effects were accompanied by significantly augmented sAC expression and increased cellular cAMP content during reperfusion. Pharmacological suppression of sAC during reperfusion reduced cellular cAMP and ameliorated reperfusion-induced mitochondrial apoptosis and ROS formation. Similarly, sAC knockdown prevented neuronal death. Further analysis revealed a role of protein kinase A (PKA), a major downstream target of sAC, in reperfusion-induced neuronal apoptosis and ROS formation. In conclusion, the results show a causal role of intracellular, sAC-dependent cAMP signaling in reperfusion-induced mitochondrial injury and apoptosis in neurons. The protective effect of sAC inhibition during the reperfusion phase provides a basis for the development of new strategies to prevent the reperfusion-induced neuronal injury.

Inhibition of Inositol 1, 4, 5-Trisphosphate Receptor Induce Breast Cancer Cell Death Through Deregulated Autophagy and Cellular Bioenergetics.

Inositol 1,4,5-trisphosphate receptors (IP3 Rs) regulate autophagy in normal cells and are associated with metastasis in cancer cells. In breast cancer, however, the regulation and role of IP3 Rs is not clear. To study this, we used MCF-7 breast cancer cell line and mouse model of breast cancer. Inhibiting IP3 R sub types resulted in compromised bioenergetics both in terms of glucose and mitochondrial metabolism. The siRNA mediated silencing of IP3 R or its blocking by its inhibitors Xestospongin C and 2-Amino-ethoxy diphenyl borate increased cell death and LC3II expression in MCF-7 cells as well as attenuated cellular bioenergetics. The level of Autophagy related gene, Atg5 was found to be up regulated after pharmacological as well as siRNA blocking of IP3 R. The specificity of its role in autophagy was confirmed through specific shRNA knockdown of the Atg5 along with IP3 R inhibitor. Inhibiting as well as silencing of IP3 R receptor also resulted in increase in ROS production which was abolished after pretreatment with N-acetyl cysteine. Its role in autophagy was confirmed through decrease in the levels of LC3 II after pretreatment with IP3 R inhibitor and N acetyl cysteine.Moreover, inhibiting as well as silencing IP3 R-induced cell death in MCF-7 cells was attenuated by autophagic inhibitors (Bafilomycin A1 or 3-Methyladeneine). In mice, blocking of IP3 Rs by 2-Amino-ethoxy diphenyl borate arrested tumor growth. Overall our findings indicate that IP3 R blocking resulted in autophagic cell death in breast cancer cells and provides a role of IP3 Rs in determining the breast cancer cell fate. J. Cell. Biochem. 118: 2333-2346, 2017. © 2017 Wiley Periodicals, Inc.

1H NMR Metabolomics Reveals Association of High Expression of Inositol 1, 4, 5 Trisphosphate Receptor and Metabolites in Breast Cancer Patients.

1H NMR is used to detect alterations in metabolites and their linkage to metabolic processes in a number of pathological conditions including breast cancer. Inositol 1, 4, 5 trisphosphate (IP3R) receptor is an intracellular calcium channel known to regulate metabolism and cellular bioenergetics. Its expression is up regulated in a number of cancers. However, its linkage to metabolism in disease conditions has not been evaluated. This study was designed to determine the association if any, of these metabolites with altered expression of IP3R in breast cancer. We used 1H NMR to identify metabolites in the serum of breast cancer patients (n = 27) and performed Real-time Polymerase Chain Reaction analysis for quantifying the expression of IP3R type 3 and type 2 in tissues from breast cancer patients (n = 40). Principal Component Analysis (PCA) and Partial Least Square-Discriminant Analysis (PLS-DA) clearly distinguished patients with high/low IP3R expression from healthy subjects. The present study revealed high expression of IP3R type 2 and type 3 in human breast tumor tissue compared to adjacent non-tumorous tissue. Moreover, patients with ≥ 2-fold increase in IP3R (high IP3R group) had significantly higher concentration of metabolic intermediates compared to those with < 2-fold increase in IP3R (low IP3R group). We observed an increase in lipoprotein content and the levels of metabolites like lactate, lysine and alanine and a decrease in the levels of pyruvate and glucose in serum of high IP3R group patients when compared to those in healthy subjects. Receiver operating characteristic (ROC) curve analysis was performed to show the clinical utility of metabolites. In addition to the human studies, functional relevance of IP3Rs in causing metabolic disruption was observed in MCF-7 and MDA MB-231 cells. Results from our studies bring forth the importance of metabolic (or metabolomics) profiling of serum by 1H NMR in conjunction with tissue expression studies for characterizing breast cancer patients. The results from this study provide new insights into relationship of breast cancer metabolites with IP3R.

Zoledronate and Molecular Iodine Cause Synergistic Cell Death in Triple Negative Breast Cancer through Endoplasmic Reticulum Stress.

Women consuming molecular iodine (I2) through seaweeds suffer the least from breast cancers. Zoledronate (Zol) is in clinical use for alleviation of bone pain in cancer patients. Triple negative breast cancers exhibit high mortality due to lack of neoadjuvant chemotherapy. I2 and Zol independently cause weak antiproliferative and apoptotic effect. So far, their combined effects have not been tested. We analyzed the effect of combination of I2 with Zol as a potent adjuvant therapeutic agent for triple negative breast cancer cells (MDA-MBA-231) and in the mice model of breast cancer. Cell viability, terminal deoxynucleotidyl transferase dUTP nick end labeling staining, Western blotting, real-time PCR, flow cytometry, and other assays were performed for assessing cell death, calcium levels, and migration potential, respectively, in treated cells. The increased caspase 8, increased [Ca(2+)]c levels, and endoplasmic reticulum (ER) stress resulted in apoptosis. Real time and fluorescence-based analysis demonstrated that the combination treatment targets ER Ca(2+) homeostasis chaperons leading to apoptosis. Combination therapy reduces metalloproteinases 2 and 9, inhibits invasion/migration of cells, and prevents growth of tumor in mice. I2 + Zol combination treatment induces synergistic increase in ER-mediated apoptosis, reduces invasion/migration potential of MDA-MB-231 cells, and exhibits antiproliferative property in vivo demonstrating its potential as combination therapy.

Evidence of apoptosis in right ventricular dysfunction in rheumatic mitral valve stenosis.

BACKGROUND & OBJECTIVES: Right ventricular (RV) dysfunction is one of the causes of morbidity and mortality in valvular heart disease. The phenomenon of apoptosis, though rare in cardiac muscle may contribute to loss of its function. Role of apoptosis in RV in patients with rheumatic valvular heart disease is investigated in this study. METHODS: Patients with rheumatic mitral valve stenosis formed two groups based on RV systolic pressure (RVSP) as RVSP <40 mmHg (group I, n=9) and RVSP ≥40 mmHg (group II, n=30). Patients having atrial septal defect (ASD) with RVSP <40 mmHg served as control (group III, n=15). Myocardial performance index was assessed for RV function. Real-time polymerase chain reaction was performed on muscle biopsy procured from RV to assess expression of pro-apoptotic genes (Bax, cytochrome c, caspase 3 and Fas) and anti-apoptotic genes (Bcl-2). Apoptosis was confirmed by histopathology and terminal deoxynucleotide-transferase-mediated dUTP nick end labelling. RESULTS: Group II had significant RV dysfunction compared to group I (P=0.05) while caspase 3 (P=0.01) and cytochrome c (P=0.03) were expressed excessively in group I. When group I was compared to group III (control), though there was no difference in RV function, a highly significant expression of pro-apoptotic genes was observed in group I (Bax, P=0.02, cytochrome c=0.001 and caspase 3=0.01). There was a positive correlation between pro-apoptotic genes. Nuclear degeneration was present conforming to apoptosis in valve disease patients (groups I and II) while it was absent in patients with ASD. INTERPRETATION & CONCLUSION: Our findings showed evidence of apoptosis in RV of patients with valvular heart disease. Apoptosis was set early in the course of rheumatic valve disease even with lower RVSP, followed by RV dysfunction; however, expression of pro-apoptotic genes regressed.

Histone deacetylase inhibition reduces hypothyroidism-induced neurodevelopmental defects in rats.

Thyroid hormone (TH) through its receptor (TRα/ß) influences spatio-temporal regulation of its target gene repertoire during brain development. Though hypothyroidism in WT rodent models of perinatal hypothyroidism severely impairs neurodevelopment, its effect on TRα/ß knockout mice is less severe. An explanation to this paradox is attributed to a possible repressive action of unliganded TRs during development. Since unliganded TRs suppress gene expression through the recruitment of histone deacetylase (HDACs) via co-repressor complexes, we tested whether pharmacological inhibition of HDACs may prevent the effects of hypothyroidism on brain development. Using valproate, an HDAC inhibitor, we show that HDAC inhibition significantly blocks the deleterious effects of hypothyroidism on rat cerebellum, evident by recovery of TH target genes like Bdnf, Pcp2 and Mbp as well as improved dendritic structure of cerebellar Purkinje neurons. Together with this, HDAC inhibition also rescues hypothyroidism-induced motor and cognitive defects. This study therefore provides an insight into the role of HDACs in TH insufficiency during neurodevelopment and their inhibition as a possible therapeutics for treatment.

Phytochemicals for breast cancer therapy: current status and future implications.

Breast cancer is one of the most common malignancies among women, representing nearly 30% of newly diagnosed cancers every year. Till date, various therapeutic interventions, including surgery, chemotherapy, hormonal therapy, and radiotherapy are available and are known to cause a significant decline in the overall mortality rate. However, therapeutic resistance, recurrence and lack of treatment in metastasis are the major challenges that need to be addressed. Increasing evidence suggests the presence of cancer stem cells (CSCs) in heterogeneous population of breast tumors capable of selfrenewal and differentiation and is considered to be responsible for drug resistance and recurrence. Therefore, compound that can target both differentiated cancer cells, as well as CSCs, may provide a better treatment strategy. Due to safe nature of dietary agents and health products, investigators are introducing them into clinical trials in place of chemotherapeutic agents.This current review focuses on phytochemicals, mainly flavonoids that are in use for breast cancer therapy in preclinical phase. As phytochemicals have several advantages in breast cancer and cancer stem cells, new synthetic series for breast cancer therapy from analogues of most potent natural molecule can be developed via rational drug design approach.

Antiviral signaling protein MITA acts as a tumor suppressor in breast cancer by regulating NF-κB induced cell death.

Emerging evidences suggest that chronic inflammation is one of the major causes of tumorigenesis. The role of inflammation in regulation of breast cancer progression is not well established. Recently Mediator of IRF3 Activation (MITA) protein has been identified that regulates NF-κB and IFN pathways. Role of MITA in the context of inflammation and cancer progression has not been investigated. In the current report, we studied the role of MITA in the regulation of cross talk between cell death and inflammation in breast cancer cells. The expression of MITA was significantly lower on in estrogen receptor (ER) positive breast cancer cells than ER negative cells. Similarly, it was significantly down regulated in tumor tissue as compared to the normal tissue. The overexpression of MITA in MCF-7 and T47D decreases the cell proliferation and increases the cell death by activation of caspases. MITA positively regulates NF-κB transcription factor, which is essential for MITA induced cell death. The activation of NF-κB induces TNF-α production which further sensitizes MITA induced cell death by activation of death receptor pathway through capsase-8. MITA expression decreases the colony forming units and migration ability of MCF-7 cells. Thus, our finding suggests that MITA acts as a tumor suppressor which is down regulated during tumorigenesis providing survival advantage to tumor cell.