Cell Survival Molecules Research Articles

UCF101 Rescues against Diabetes-Evoked Cardiac Remodeling and Contractile Anomalies through AMPK-Mediated Induction of Mitophagy.

Diabetes mellitus is known to provoke devastating anomalies in myocardial structure and function while effective therapeutic regimen is still lacking. The selective protease inhibitor UCF101 (5-[5-(2-nitrophenyl) furfuryliodine]-1,3-diphenyl-2-thiobarbituric acid) has been shown to fend off ischemic heart injury although its impact on diabetic cardiomyopathy remains elusive. Our present work was conducted to examine the effect of UCF101 on experimental diabetes-evoked cardiac geometric and functional abnormalities as well as mechanism involved. Adult mice were made diabetic using streptozotocin (STZ) while receiving UCF101 (7.15 mg/kg, i.p.) for 6 consecutive days. STZ evidently evoked cardiac hypertrophy, interstitial fibrosis, mitochondrial ultrastructural damage, oxidative stress, dampened autophagy (LC3B, Beclin1, elevated p62), mitophagy (FUNDC1 and Parkin with elevated TOM20), increased left ventricular (LV) end systolic diameter, dampened fractional shortening, ejection fraction, cardiomyocyte shortening capacity, velocities of shortening/relengthening, and rise in intracellular Ca2+ in conjunction with elongated diastole and intracellular Ca2+ removal, the responses were overtly reconciled by UCF101 with little effect from UCF101 itself. Levels of cell injury markers Omi/HtrA2, TNFα, and stress signaling (JNK, ERK, p38) were overtly enhanced along with compromised phosphorylation of cellular fuel AMPK (Thr172) and cell survival molecule GSK3β, as well as downregulated SERCA2a and elevated phospholamban, the effect was reversed by UCF101 (except for SERCA2a). AMPK knockout, pharmacological inhibition, mitophagy inhibitor liensinine and parkin knockout nullified UCF101-offered cardioprotection in diabetes. UCF101 reversed STZ-induced upregulation in the AMPK degrading enzymes PP2A and PP2C. These findings denote that UCF101 rescues diabetes-instigated alterations in cardiac structure and contraction, likely through AMPK-mediated regulation of mitophagy.

Perspective: Can early embryonic losses be reduced in lactating dairy cows?

Perspective: Can early embryonic losses be reduced in lactating dairy cows?

Regularized Mixture Cure Models Identify a Gene Signature That Improves Risk Stratification within the Favorable-Risk Group in 2017 European Leukemianet (ELN) Classification of Acute Myeloid Leukemia (Alliance 152010)

Introduction: The 2017 ELN Favorable-risk group comprises specific recurrent cytogenetic and molecular alterations. Assignment to this group has important clinical implications, as allogeneic stem cell transplantation in first complete remission (CR) is not advised due to a relatively good outcome of patients (pts) receiving chemotherapy and transplant-associated mortality. However, not all Favorable-risk pts experience long-term survival and their outcomes are affected by co-occurring genetic features making recognition of pts who would most likely be cured of high importance. Thus, we used our regularized mixture cure model (MCM) that embeds false discovery rate control to identify prognostically relevant transcripts that can distinguish pts cured from pts susceptible to lower- or higher-risk of relapse. Methods: We analyzed 312 pts <60 years with de novo AML classified in the 2017 ELN Favorable-risk group excluding APL who achieved a CR, had RNA-seq data available, and treated on one of 8 CALGB/Alliance frontline protocols with intensive 7+3-based induction chemotherapy. No pt received an allogeneic stem cell transplant in first CR. MCMs assume the population consists of 2 subgroups, cured and susceptible, thus there are 2 regression components, which permit identification of features associated with cure and/or latency of susceptible pts. 'Cured' is synonymous with attaining long-term relapse-free survival and thus pts have a survival probability of 1. We fit univariable MCMs to identify baseline demographic, clinical features, or selected gene mutations related to the probability of being cured and/or to the latency distribution (time to relapse). RNA-seq expression values were candidate covariates in a regularized MCM to identify a parsimonious list of transcripts associated with cure or latency. We then used 2017 ELN Favorable pts in an independent dataset (GSE37642) for validation. Results: The estimated proportion cured (39.5%) was significant (P < 0.001) indicating that a MCM should be fit. Other than % of bone marrow blasts (P = 0.009) and % of blood blasts (P = 0.048), no other pretreatment features were significant in univariable MCMs. CEBPAdouble and TET2 mutations were the only ones significantly associated with latency (P = 0.008 and P = 0.013, respectively), but neither was associated with cure (P = 0.881 and P = 0.507, respectively). Our regularized MCM identified 101 transcripts associated with cure and 71 transcripts associated with latency. Kaplan-Meier curves of cured vs susceptible pts as well as of those susceptible with lower vs higher risk of relapse or death were well separated. We mapped the 168 unique transcripts to GSE37642 Affymetrix HG-U133Plus2 GeneChip for validation and found that 65 cure-related probe sets and 57 latency probe sets mapped to 34 and 32 unique genes, respectively. The validation data yielded AUC=0.788 and C-statistic=0.887, indicating good predictive ability of the selected genes. As desired, the predicted cured group had a survival probability of 1 throughout the observation period (Fig 1), with good separation between predicted susceptibles in the lower- versus higher-risk groups (Fig 2). Cell death and survival was the top molecular/cellular function for both the cure and latency portions of the model with 22 and 20 transcripts involved, respectively, with only BRD2, HLA-A, HLA-B, NAIP, and TXNIP in common. Cell death and survival molecules unique to the latency portion of the model included CD300A, CRNDE, DDX39B, FAS, GPI, HLA-DRA, KLF13, LAT, let-7, LMO2, LSP1, NOTCH1, PLCG2, PSMB8, and U2AF1; those unique to the cure portion included ARID5B, BAG6, BMI1, CCL5, CDK7, DPPA4, ELOVL5, HLA-DRB1, IL18, INTS6, MAP4K4, mir-25, mir-491, NOMO1, NR1H3, RPS16, and TUBB. Conclusion: Our regularized MCM identified important subsets of genes associated with cure and latency in the 2017 ELN Favorable-risk pts. Our results suggest that the Favorable-risk group includes distinct transcriptionally defined subgroups with different biological properties, which may be useful for refining this risk category by identification of pts who might be cured with chemotherapy alone. Given similar treatment with 7+3-based cytotoxic chemotherapy, the identified subgroups (cured, susceptible lower risk, susceptible higher risk) seem to have different sensitivities to 7+3-based therapy. Support: R01LM013879, U10CA180821, U10CA180882, U24CA196171 Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Protective Role of Corticosterone against Hydrogen Peroxide-Induced Neuronal Cell Death in SH-SY5Y Cells.

Stress breaks body balance, which can cause diverse physiological disorders and worsen preexisting diseases. However, recent studies have reported that controllable stress and overcoming from stress reinforce resilience to resist against more intense stress afterwards. In this study, we investigated the protective effect of corticosterone (CORT), a representative stress hormone against hydrogen peroxide (H2O2)-induced neuronal cell death and its underlying molecular mechanism in SH-SY5Y cells, a human neuroblastoma cell line. The decreased cell viability by H2O2 was effectively restored by the pretreatment with low concentration of CORT (0.03 μM for 72 h) in the cells. H2O2-increased expression of apoptotic markers such as PUMA and Bim was decreased by CORT pretreatment. Furthermore, pretreatment of CORT attenuated H2O2-mediated oxidative damages by upregulation of antioxidant enzymes via activation of nuclear factor erythroid 2-related factor 2 (Nrf2). These findings suggest that low concentration of CORT with eustressed condition enhances intracellular self-defense against H2O2-mediated oxidative cell death, suggesting a role of low concentration of CORT as one of key molecules for resilience and neuronal cell survival.

Relative refractoriness of breast cancer cells to tumour necrosis factor-α induced necroptosis.

Necroptosis, a recently identified programmed cell death pathway, has attracted attention as an alternative route to target apoptosis-resistant cancer cells. The status of the necroptosis pathway in different subtypes of breast cancer has not been well explored. Stimulating the cells by TNF-α can trigger cell survival or death depending on the combination of downstream players involved. In this work, we attempted to induce necroptosis in them using a combination of TNF-α and Z-VAD-FMK with and without chemotherapy. Cell viability, apoptosis, and necroptosis were assessed using MTT and Annexin-V/PI assays, respectively. Gene and protein expression was analysed by qPCR and immunophenotyping. Both the cell lines were resistant to induction of cell death by necroptosis. There was no enhancement in cell death when chemotherapeutic drugs were combined with necroptosis induction. Expression studies showed reduced translational expression of key necroptosis molecules like RIP kinases and MLKL in breast cancer cells compared to positive control cell line L929. Also, cell survival molecules were expressed more in MDA-MB-231 in contrast to death pathway molecules which were expressed more in T47D cells. In this work, the two breast cancer cell lines were observed to be resistant to TNF-α induced necroptosis with or without chemotherapy. Expression of key necroptosis players revealed relative insufficiency of the molecular machinery involved in the above pathway. In our opinion this may be the cause for resistance to necroptosis and novel strategies to upregulate these molecules need to be developed to sensitize the breast cancer cells towards cell death by necroptosis.

RHEB is a potential therapeutic target in T cell acute lymphoblastic leukemia

T cell acute lymphoblastic leukemia (T-ALL) is an aggressive malignancy of immature T lymphocytes. Although various therapeutic approaches have been developed, refractoriness of chemotherapy and relapse cause a poor prognosis of the disease and further therapeutic strategies are required. Here, we report that Ras homolog enriched in brain (RHEB), a critical regulator of mTOR complex 1 activity, is a potential target for T-ALL therapy. In this study, we established an sgRNA library that comprehensively targeted mTOR upstream and downstream pathways, including autophagy. CRISPR/Cas9 dropout screening revealed critical roles of mTOR-related molecules in T-ALL cell survival. Among the regulators, we focused on RHEB because we previously found that it is dispensable for normal hematopoiesis in mice. Transcriptome and metabolic analyses revealed that RHEB deficiency suppressed de novo nucleotide biosynthesis, leading to human T-ALL cell death. Importantly, RHEB deficiency suppressed tumor growth in both mouse and xenograft models. Our data provide a potential strategy for efficient therapy of T-ALL by RHEB-specific inhibition.

Natural Biopolymers as Additional Tools for Cell Microencapsulation Applied to Cellular Therapy.

One of the limitations in organ, tissue or cellular transplantations is graft rejection. To minimize or prevent this, recipients must make use of immunosuppressive drugs (IS) throughout their entire lives. However, its continuous use generally causes several side effects. Although some IS dose reductions and withdrawal strategies have been employed, many patients do not adapt to these protocols and must return to conventional IS use. Therefore, many studies have been carried out to offer treatments that may avoid IS administration in the long term. A promising strategy is cellular microencapsulation. The possibility of microencapsulating cells originates from the opportunity to use biomaterials that mimic the extracellular matrix. This matrix acts as a support for cell adhesion and the syntheses of new extracellular matrix self-components followed by cell growth and survival. Furthermore, by involving the cells in a polymeric matrix, the matrix acts as an immunoprotective barrier, protecting cells against the recipient’s immune system while still allowing essential cell survival molecules to diffuse bilaterally through the polymer matrix pores. In addition, this matrix can be associated with IS, thus diminishing systemic side effects. In this context, this review will address the natural biomaterials currently in use and their importance in cell therapy.

Stimulating the expression of sphingosine kinase 1 (SphK1) is beneficial to reduce acrylamide-induced nerve cell damage

Sphingosine kinase 1 (SphK1) is an important signaling molecule for cell proliferation and survival. However, the role of SphK1 in acrylamide (ACR)-induced nerve injury remains unclear. The purpose of this study was to investigate the role and potential mechanism of SphK1 in ACR-induced nerve injury. Liquid chromatography triple quadrupole tandem mass spectrometry (LC-MS/MS) and reverse transcription-quantitative PCR (RT-qPCR) were used to detect sphingosine 1-phosphate (S1P) content in serum and SphK1 content in whole blood from an occupational work group exposed to ACR compared to a non-exposed group. For in vitro experiments, SphK1 in human SH-SY5Y neuroblastoma cells was activated using SphK1-specific activator phorbol 12-myristate 13-acetate (PMA). Our research also utilized cell viability assays, flow cytometry, western blots, RT-qPCR and related protein detection to assess activity of the mitogen activated protein kinase (MAPK) signaling pathway. The results of the population study showed that the contents of SphK1 and S1P in the ACR-exposed occupational contact group were lower than in the non-exposed group. The results of in vitro experiments showed that expression of SphK1 decreased with the increase in ACR concentration. Activating SphK1 improved the survival rate of SH-SY5Y cells and decreased the apoptosis rate. Activating SphK1 in SH-SY5Y cells also regulated MAPK signaling, including enhancing the phosphorylation of extracellular signal-regulated protein kinases (ERK) and inhibiting the phosphorylation of c-Jun N-terminal kinase (JNK) and p38. These results suggest that activating SphK1 can protect against nerve cell damage caused by ACR.

Reductive TCA cycle catalyzed by wild-type IDH2 promotes acute myeloid leukemia and is a metabolic vulnerability for potential targeted therapy

BackgroundIsocitrate dehydrogenase-2 (IDH2) is a mitochondrial enzyme that catalyzes the metabolic conversion between isocitrate and alpha-ketoglutarate (α-KG) in the TCA cycle. IDH2 mutation is an oncogenic event in acute myeloid leukemia (AML) due to the generation of 2-hydroxyglutarate. However, the role of wild-type IDH2 in AML remains unknown, despite patients with it suffer worse clinical outcome than those harboring mutant type.MethodsIDH2 expression in AML cell lines and patient samples was evaluated by RT-qPCR, western blotting and database analyses. The role of wild-type IDH2 in AML cell survival and proliferation was tested using genetic knockdown and pharmacological inhibition in AML cells and animal models. LC–MS, GC–MS, isotope metabolic tracing, and molecular analyses were performed to reveal the underlying mechanisms.ResultsWe found that wild-type IDH2 was overexpressed in AML and played a major role in promoting leukemia cell survival and proliferation in vitro and in vivo. Metabolomic analyses revealed an active IDH2-mediated reductive TCA cycle that promoted the conversion of α-KG to isocitrate/citrate to facilitate glutamine utilization for lipid synthesis in AML cells. Suppression of wild-type IDH2 by shRNA resulted in elevated α-KG and decreased isocitrate/citrate, leading to reduced lipid synthesis, a significant decrease in c-Myc downregulated by α-KG, and an inhibition of AML viability and proliferation. Importantly, pharmacological inhibition of IDH2 showed significant therapeutic effect in mice inoculated with AML cells with wt-IDH2 and induced a downregulation of C-MYC in vivo.ConclusionsWt-IDH2 is an essential molecule for AML cell survival and proliferation by promoting conversion of α-KG to isocitrate for lipid synthesis and by upregulating c-Myc expression and could be a potential therapeutic target in AML.

Delayed Therapeutic Administration of Melatonin Enhances Neuronal Survival Through AKT and MAPK Signaling Pathways Following Focal Brain Ischemia in Mice.

Melatonin has a role in the cell survival signaling pathways as a candidate for secondary stroke prevention. Therefore, in the present study, the coordination of ipsilateral and contralateral hemispheres to evaluate delayed post-acute effect of melatonin was examined on recovery of the cell survival and apoptosis after stroke. Melatonin was administered (4mg/kg/day) intraperitoneally for 45days, starting 3days after 30min of middle cerebral artery occlusion. The genes and proteins related to the cell survival and apoptosis were investigated by immunofluorescence, western blotting, and RT-PCR techniques after behavioral experiments. Melatonin produced delayed neurological recovery by improving motor coordination on grip strength and rotarod tests. This neurological recovery was also reflected by high level of NeuN positive cells and low level of TUNEL-positive cells suggesting enhanced neuronal survival and reduced apoptosis at the fifty-fifth day of stroke. The increase of NGF, Nrp1, c-jun; activation of AKT; and dephosphorylation of ERK and JNK at the fifty-fifth day showed that cell survival and apoptosis signaling molecules compete to contribute to the remodeling of brain. Furthermore, an increase in the CREB and Atf-1 expressions suggested the melatonin's strong reformative effect on neuronal regeneration. The contralateral hemisphere was more active at the latter stages of the molecular and functional regeneration which provides a further proof of principle about melatonin's action on the promotion of brain plasticity and recovery after stroke.

Methyl Jasmonate Cytotoxicity and Chemosensitization of T Cell Lymphoma In Vitro Is Facilitated by HK 2, HIF-1α, and Hsp70: Implication of Altered Regulation of Cell Survival, pH Homeostasis, Mitochondrial Functions.

Methyl jasmonate (MJ) displays antineoplastic potential against numerous neoplastic cells. However, several mechanistic aspects of its antineoplastic action against malignancies of T cell origin remain elusive. The present investigation reports the novel targets of MJ and mechanistic pathways of MJ-mediated antineoplastic and chemosensitizing action against tumor cells derived from murine T-cell lymphoma, designated as Dalton’s lymphoma (DL). The present study demonstrates that MJ directly docks to HIF-1α, hexokinase 2, and Hsp70 at prominent binding sites. MJ exhibits tumoricidal action against tumor cells via induction of apoptosis and necrosis through multiple pathways, including declined mitochondrial membrane potential, enhanced expression of ROS, altered pH homeostasis, an elevated level of cytosolic cytochrome c, and modulated expression of crucial cell survival and metabolism regulatory molecules. Additionally, this study also reports the chemosensitizing ability of MJ against T cell lymphoma accompanied by a declined expression of MDR1. This study sheds new light by demonstrating the implication of novel molecular mechanisms underlying the antitumor action of MJ against T-cell lymphoma and hence has immense translational significance.

Geometrically Controlled Liquefied Capsules for Modular Tissue Engineering Strategies.

A plethora of bioinspired cell-laden hydrogels are being explored as building blocks that once assembled are able to create complex and highly hierarchical structures recapitulating the heterogeneity of living tissues. Yet, the resulting 3D bioengineered systems still present key limitations, mainly related with limited diffusion of essential molecules for cell survival, which dictates the failure of most strategies upon implantation. To maximize the hierarchical complexity of bioengineered systems, while simultaneously fully addressing the exchange efficiency of biomolecules, the high-throughput fabrication of liquefied capsules is proposed using superhydrophobic-superhydrophilic microarrays as platforms to produce the initial structures with high fidelity of geometry and size. The liquefied capsules are composed by i) a permselective multilayered membrane; ii) surface-functionalized poly(ε-caprolactone) microparticles loaded into the liquefied core acting as cell adhesion sites; and iii) cells. It is demonstrated that besides the typical spherical liquefied capsules, it is also possible to obtain multi-shaped blocks with high geometrical precision and efficiency. Importantly, the internal gelation approach used to produce such blocks does not jeopardize cell viability, evidencing the mild conditions of the proposed cell encapsulation technique. The proposed system is intended to be used as hybrid devices implantable using minimally invasive procedures for multiple tissue engineering applications.

Protective Effects of Simvastatin on Endotoxin-Induced Acute Kidney Injury through Activation of Tubular Epithelial Cells' Survival and Hindering Cytochrome C-Mediated Apoptosis.

Increasing evidence suggests that apoptosis of tubular cells and renal inflammation mainly determine the outcome of sepsis-associated acute kidney injury (AKI). The study aim was to investigate the molecular mechanism involved in the renoprotective effects of simvastatin in endotoxin (lipopolysaccharide, LSP)-induced AKI. A sepsis model was established by intraperitoneal injection of a single non-lethal LPS dose after short-term simvastatin pretreatment. The severity of the inflammatory injury was expressed as renal damage scores (RDS). Apoptosis of tubular cells was detected by Terminal deoxynucleotidyl transferase-mediated dUTP Nick End Labeling (TUNEL assay) (apoptotic DNA fragmentation, expressed as an apoptotic index, AI) and immunohistochemical staining for cleaved caspase-3, cytochrome C, and anti-apoptotic Bcl-xL and survivin. We found that endotoxin induced severe renal inflammatory injury (RDS = 3.58 ± 0.50), whereas simvastatin dose-dependently prevented structural changes induced by LPS. Furthermore, simvastatin 40 mg/kg most profoundly attenuated tubular apoptosis, determined as a decrease of cytochrome C, caspase-3 expression, and AIs (p < 0.01 vs. LPS). Conversely, simvastatin induced a significant increase of Bcl-XL and survivin, both in the strong inverse correlations with cleaved caspase-3 and cytochrome C. Our study indicates that simvastatin has cytoprotective effects against LPS-induced tubular apoptosis, seemingly mediated by upregulation of cell-survival molecules, such as Bcl-XL and survivin, and inhibition of the mitochondrial cytochrome C and downstream caspase-3 activation.

DMD – THERAPY: P.284 ATL1102 treatment improves PUL2.0 in non-ambulant boys with Duchenne muscular dystrophy compared to a natural history control

ATL1102, an antisense drug which targets CD49d, an immune cell adhesion, survival and activation molecule, is being evaluated in an open label study in nine adolescent non-ambulant patients with Duchenne muscular dystrophy (DMD) ACTRN12618000970246. The nine patients, 12 to 18 years old (mean 14.9 (SD 2.1) years), were dosed with ATL1102 once weekly at 25mg s.c. for 24 weeks and were assessed using the Performance of the Upper Limb Module (PUL2.0). The data of the ATL1102-treated patients (8 of 9 on corticosteroid) was compared with the 24-week PUL2.0 data of 20 patients (mean age 15.61 (SD 2.02) years; 19 on corticosteroid) from a natural history database of patients in Rome, Italy.

Leachable-Free Fabrication of Hydrogel Foams Enabling Homogeneous Viability of Encapsulated Cells in Large-Volume Constructs.

The popularity of cell-laden injectable hydrogels has steeply increased due to their compatibility with minimally invasive surgical procedures. However, the diffusion of indispensable molecules for cell survival through bulk hydrogel structures, particularly oxygen, is often limited to micrometric distances, often hampering cell viability or uniform tissue formation in constructs with clinically relevant sizes. The introduction of micropores in hydrogels or the use of oxygen-generating materials has enabled combining advantages of porous 3D scaffolds with the injectability properties of in situ-solidifying hydrogels. Here, cell-laden injectable gelatin methacryloyl (GelMA) foams are fabricated using a single polymer formulation. Air bubbles are introduced into GelMA solutions using a simple-to-implement method based on pulling/pushing the solution through a syringe. Human mesenchymal stem cells derived from the adipose tissue (hASCs) cultured in bulk hydrogels (diameter c.a. 5 mm) show low permanence in the core of the materials and stain for factors associated to hypoxia (hypoxia-inducible factor-1 alpha (HIF-1α)) after 7 days of culture. In opposition, cells cultured in optimized foams do not stain for HIF-1α, show high permanence, homogeneous viability, and consistent phenotype in the whole depth of the biomaterials, while secreting increased amounts of regenerative growth factors to the surrounding medium.

Macrophage migration inhibitory factor inhibition as a novel therapeutic approach against triple-negative breast cancer

Triple-negative breast cancer (TNBC), defined as loss of estrogen, progesterone, and Her2 receptors, is a subtype of highly aggressive breast cancer with worse prognosis and poor survival rate. Macrophage migration inhibitory factor (MIF) is a pleiotropic pro-inflammatory cytokine aberrantly expressed in many solid tumors and known to promote tumor progression and metastasis. However, its role in TNBC progression and metastasis is unexplored. Here we have shown that in TNBC patients, MIF expression was significantly enriched in the tumor compared to adjacent normal tissue. Using publically available patient datasets, we showed that MIF overexpression correlates with worse survival in TNBC compared to other hormonal status. Orthotopic implantation of TNBC cells into MIF knockout mice showed reduced tumor growth compared to wild-type mice. In addition, we have shown that MIF downregulation inhibits TNBC growth and progression in a syngeneic mouse model. We further showed that CPSI-1306, a small-molecule MIF inhibitor, inhibits the growth of TNBC cells in vitro. Mechanistic studies revealed that CPSI-1306 induces intrinsic apoptosis by alteration in mitochondrial membrane potential, cytochrome c (Cyt c) release, and activation of different caspases. In addition, CPSI-1306 inhibits the activation of cell survival and proliferation-related molecules. CPSI-1306 treatment also reduced the tumor growth and metastasis in orthotopic mouse models of mammary carcinoma. CPSI-1306 treatment of tumor-bearing mice significantly inhibited TNBC growth and pulmonary metastasis in a dose-dependent manner. Histological analysis of xenograft tumors revealed a higher number of apoptotic cells in CPSI-1306-treated tumors compared to vehicle controls. Our studies, for the first time, show that MIF overexpression in TNBC enhances growth and metastasis. Taken together, our results indicate that using small molecular weight MIF inhibitors could be a promising strategy to inhibit TNBC progression and metastasis.

Evidences of G Coupled-Protein Receptor (GPCR) Signaling in the human Malaria Parasite Plasmodium falciparum for Sensing its Microenvironment and the Role of Purinergic Signaling in Malaria Parasites.

The nucleotides were discovered in the early 19th century and a few years later, the role of such molecules in energy metabolism and cell survival was postulated. In 1972, a pioneer work by Burnstock and colleagues suggested that ATP could also work as a neurotransmitter, which was known as the "purinergic hypothesis". The idea of ATP working as a signaling molecule faced initial resistance until the discovery of the receptors for ATP and other nucleotides, called purinergic receptors. Among the purinergic receptors, the P2Y family is of great importance because it comprises of G proteincoupled receptors (GPCRs). GPCRs are widespread among different organisms. These receptors work in the cells' ability to sense the external environment, which involves: to sense a dangerous situation or detect a pheromone through smell; the taste of food that should not be eaten; response to hormones that alter metabolism according to the body's need; or even transform light into an electrical stimulus to generate vision. Advances in understanding the mechanism of action of GPCRs shed light on increasingly promising treatments for diseases that have hitherto remained incurable, or the possibility of abolishing side effects from therapies widely used today.

The novel HOCl fluorescent probe CAN induced A549 apoptosis by inhibiting chlorination activity of MPO

Hypochlorous acid (HOCl) is an important signaling molecule for cell survival. However, it has been reported that excessive HOCl contributes to a variety of diseases such as cancers. And in cancer cells, the level of HOCl is much higher than that in normal cells. Here a coumarin-based fluorescent probe 7-Diethylamino-3-(2,3-dihydro-1H-perimidin-2-yl)-chromen-2-one (CAN) was successfully developed for HOCl detection. The probe could be oxidized by HOCl to induce significant change in its fluorescence profile, which made it feasible for ratiometric detecting HOCl. CAN (below 1 µM) did not affect cell viability and had good capacity in ratiometric detection of HOCl in RAW 264.7 cells. CAN induced A549 apoptosis and inhibited tumor growth in vitro and in vivo. And CAN could decrease the chlorination activity of myeloperoxidase (MPO) in A549. These findings suggested that CAN (below 1 µM) would develop into a HOCl probe. High activity of MPO and level of HOCl might be helpful for A549 survival. A549 could be induced apoptosis by reducing the HOCl level by CAN. It implies a new anticancer strategy by targeting HOCl.

Endonuclease VIII-like 1 deficiency impairs survival of newly generated hippocampal neurons and memory performance in young-adult male mice

AimsEfficient memory formation in rodents depends on adult neurogenesis in the subgranular zone of the hippocampus, and mounting evidence suggests that deficiencies in initiating repair of oxidatively induced DNA damage may impair neurogenesis. Hence, we aimed to determine whether loss of the DNA glycosylase, endonuclease VIII-like 1 (Neil1), affects hippocampal neurogenesis and memory performance in young-adult mice. Main methodsEight-week-old male wild-type and Neil1-deficient (Neil1−/−) mice were treated with bromodeoxyuridine to track neuronal proliferation and differentiation. A neurosphere formation assay was further used to measure neuroprogenitor proliferative capacity. Hippocampus-related memory functions were assessed with Y-maze spontaneous alternation and novel object recognition tests. Key findingsYoung-adult male Neil1−/− mice exhibited diminished adult hippocampal neurogenesis in the dentate gyrus, probably as a result of poor survival of newly proliferated neurons. Furthermore, the Y-maze spontaneous alternation and novel object recognition tests respectively revealed that Neil1 deficiency impairs spatial and non-spatial hippocampus-related memory functions. We also found that expression of p53, a central regulator of apoptosis, was upregulated in the dentate gyrus of Neil1−/− mice, while the level of β-catenin, a key cell survival molecule, was downregulated. SignificanceThe DNA glycosylase, Neil1, promotes successful hippocampal neurogenesis and learning and memory in young-adult mice.

Sevoflurane Pre-conditioning Ameliorates Diabetic Myocardial Ischemia/Reperfusion Injury Via Differential Regulation of p38 and ERK

Diabetes mellitus (DM) significantly increases myocardial ischemia/reperfusion (MI/R) injury. During DM, cardioprotection induced by conventional pre-conditioning (PreCon) is decreased due to impaired AMP-activated protein kinase (AMPK) signaling. The current study investigated whether PreCon with inhaled anesthetic sevoflurane (SF-PreCon) remains cardioprotective during DM, and identified the involved mechanisms. Normal diet (ND) and high-fat diet (HFD)-induced DM mice were randomized into control and SF-PreCon (3 cycles of 15-minute period exposures to 2% sevoflurane) groups before MI/R. SF-PreCon markedly reduced MI/R injury in DM mice, as evidenced by improved cardiac function (increased LVEF and ±Dp/dt), decreased infarct size, and decreased apoptosis. To determine the relevant role of AMPK, the effect of SF-PreCon was determined in cardiac-specific AMPKα2 dominant negative expressing mice (AMPK-DN). SF-PreCon decreased MI/R injury in AMPK-DN mice. To explore the molecular mechanisms responsible for SF-PreCon mediated cardioprotection in DM mice, cell survival molecules were screened. Interestingly, in ND mice, SF-PreCon significantly reduced MI/R-induced activation of p38, a pro-death MAPK, without altering ERK and JNK. In DM and AMPK-DN mice, the inhibitory effect of SF-PreCon upon p38 activation was significantly blunted. However, SF-PreCon significantly increased phosphorylation of ERK1/2, a pro-survival MAPK in DM and AMPK-DN mice. We demonstrate that SF-PreCon protects the heart via AMPK-dependent inhibition of pro-death MAPK in ND mice. However, SF-PreCon exerts cardioprotective action via AMPK-independent activation of a pro-survival MAPK member in DM mice. SF-PreCon may be beneficial compared to conventional PreCon in diabetes or clinical scenarios in which AMPK signaling is impaired.