Effect of Src Kinase inhibition on Cytochrome c, Smac/DIABLO and Apoptosis Inducing Factor (AIF) Following Cerebral Hypoxia-Ischemia in Newborn Piglets

We have previously shown that cerebral Hypoxia-ischemia (HI) results in activation of Src kinase in the newborn piglet brain. We investigated the regulatory mechanism by which the pre-apoptotic proteins translocate from mitochondria to the cytosol during HI through the Src kinase. Newborn piglets were divided into 3 groups (n = 5/group): normoxic (Nx), HI and HI pre-treated with Src kinase inhibitor PP2 (PP2 + HI). Brain tissue HI was verified by neuropathological analysis and by Adenosine Triphosphate (ATP) and Phosphocreatine (PCr) levels. We used western blots, immunohistochemistry, H&E and biochemical enzyme assays to determine the role of Src kinase on mitochondrial membrane apoptotic protein trafficking. HI resulted in decreased ATP and PCr levels, neuropathological changes and increased levels of cytochrome c, Smac/DIABLO and AIF in the cytosol while their levels were decreased in mitochondria compared to Nx. PP2 decreased the cytosolic levels of pre-apoptotic proteins, attenuated the neuropathological changes and apoptosis and decreased the HI-induced increased activity of caspase-3. Our data suggest that Src kinase may represent a potential target that could interrupt the enzymatic activation of the caspase dependent cell death pathway.

Macrophages: Their role, activation and polarization in pulmonary diseases

Macrophages, circulating in the blood or concatenated into different organs and tissues constitute the first barrier against any disease. They are foremost controllers of both innate and acquired immunity, healthy tissue homeostasis, vasculogenesis and congenital metabolism. Two hallmarks of macrophages are diversity and plasticity due to which they acquire a wobbling array of phenotypes. These phenotypes are appropriately synchronized responses to a variety of different stimuli from either the tissue microenvironment or - microbes or their products. Based on the phenotype, macrophages are classified into classically activated/(M1) and alternatively activated/(M2) which are further sub-categorized into M2a, M2b, M2c and M2d based upon gene expression profiles. Macrophage phenotype metamorphosis is the regulating factor in initiation, progression, and termination of numerous inflammatory diseases. Several transcriptional factors and other factors controlling gene expression such as miRNAs contribute to the transformation of macrophages at different points in different diseases. Understanding the mechanisms of macrophage polarization and modulation of their phenotypes to adjust to the micro environmental conditions might provide us a great prospective for designing novel therapeutic strategy. In view of the above, this review summarises the activation of macrophages, the factors intricated in activation along with benefaction of macrophage polarization in response to microbial infections, pulmonary toxicity, lung injury and other inflammatory diseases such as chronic obstructive pulmonary dysplasia (COPD), bronchopulmonary dysplasia (BPD), asthma and sepsis, along with the existing efforts to develop therapies targeting this facet of macrophage biology.

GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral

On August 17, 2017 at 12∶41:04 UTC the Advanced LIGO and Advanced Virgo gravitational-wave detectors made their first observation of a binary neutron star inspiral. The signal, GW170817, was detected with a combined signal-to-noise ratio of 32.4 and a false-alarm-rate estimate of less than one per 8.0×10^{4}  years. We infer the component masses of the binary to be between 0.86 and 2.26  M_{⊙}, in agreement with masses of known neutron stars. Restricting the component spins to the range inferred in binary neutron stars, we find the component masses to be in the range 1.17-1.60  M_{⊙}, with the total mass of the system 2.74_{-0.01}^{+0.04}M_{⊙}. The source was localized within a sky region of 28  deg^{2} (90% probability) and had a luminosity distance of 40_{-14}^{+8}  Mpc, the closest and most precisely localized gravitational-wave signal yet. The association with the γ-ray burst GRB 170817A, detected by Fermi-GBM 1.7 s after the coalescence, corroborates the hypothesis of a neutron star merger and provides the first direct evidence of a link between these mergers and short γ-ray bursts. Subsequent identification of transient counterparts across the electromagnetic spectrum in the same location further supports the interpretation of this event as a neutron star merger. This unprecedented joint gravitational and electromagnetic observation provides insight into astrophysics, dense matter, gravitation, and cosmology.

GW170814: A Three-Detector Observation of Gravitational Waves from a Binary Black Hole Coalescence

On August 14, 2017 at 10∶30:43 UTC, the Advanced Virgo detector and the two Advanced LIGO detectors coherently observed a transient gravitational-wave signal produced by the coalescence of two stellar mass black holes, with a false-alarm rate of ≲1 in 27 000 years. The signal was observed with a three-detector network matched-filter signal-to-noise ratio of 18. The inferred masses of the initial black holes are 30.5_{-3.0}^{+5.7}M_{⊙} and 25.3_{-4.2}^{+2.8}M_{⊙} (at the 90% credible level). The luminosity distance of the source is 540_{-210}^{+130}  Mpc, corresponding to a redshift of z=0.11_{-0.04}^{+0.03}. A network of three detectors improves the sky localization of the source, reducing the area of the 90% credible region from 1160   deg^{2} using only the two LIGO detectors to 60  deg^{2} using all three detectors. For the first time, we can test the nature of gravitational-wave polarizations from the antenna response of the LIGO-Virgo network, thus enabling a new class of phenomenological tests of gravity.

GW170104: Observation of a 50-Solar-Mass Binary Black Hole Coalescence at Redshift 0.2

We describe the observation of GW170104, a gravitational-wave signal produced by the coalescence of a pair of stellar-mass black holes. The signal was measured on January 4, 2017 at 10∶11:58.6 UTC by the twin advanced detectors of the Laser Interferometer Gravitational-Wave Observatory during their second observing run, with a network signal-to-noise ratio of 13 and a false alarm rate less than 1 in 70 000 years. The inferred component black hole masses are 31.2_{-6.0}^{+8.4}M_{⊙} and 19.4_{-5.9}^{+5.3}M_{⊙} (at the 90% credible level). The black hole spins are best constrained through measurement of the effective inspiral spin parameter, a mass-weighted combination of the spin components perpendicular to the orbital plane, χ_{eff}=-0.12_{-0.30}^{+0.21}. This result implies that spin configurations with both component spins positively aligned with the orbital angular momentum are disfavored. The source luminosity distance is 880_{-390}^{+450}  Mpc corresponding to a redshift of z=0.18_{-0.07}^{+0.08}. We constrain the magnitude of modifications to the gravitational-wave dispersion relation and perform null tests of general relativity. Assuming that gravitons are dispersed in vacuum like massive particles, we bound the graviton mass to m_{g}≤7.7×10^{-23}  eV/c^{2}. In all cases, we find that GW170104 is consistent with general relativity.

Nicotinamide adenine dinucleotide biosynthesis promotes liver regeneration

The regenerative capacity of the liver is essential for recovery from surgical resection or injuries induced by trauma or toxins. During liver regeneration, the concentration of nicotinamide adenine dinucleotide (NAD) falls, at least in part due to metabolic competition for precursors. To test whether NAD availability restricts the rate of liver regeneration, we supplied nicotinamide riboside (NR), an NAD precursor, in the drinking water of mice subjected to partial hepatectomy. NR increased DNA synthesis, mitotic index, and mass restoration in the regenerating livers. Intriguingly, NR also ameliorated the steatosis that normally accompanies liver regeneration. To distinguish the role of hepatocyte NAD levels from any systemic effects of NR, we generated mice overexpressing nicotinamide phosphoribosyltransferase, a rate-limiting enzyme for NAD synthesis, specifically in the liver. Nicotinamide phosphoribosyltransferase overexpressing mice were mildly hyperglycemic at baseline and, similar to mice treated with NR, exhibited enhanced liver regeneration and reduced steatosis following partial hepatectomy. Conversely, mice lacking nicotinamide phosphoribosyltransferase in hepatocytes exhibited impaired regenerative capacity that was completely rescued by administering NR.

CONCLUSION

NAD availability is limiting during liver regeneration, and supplementation with precursors such as NR may be therapeutic in settings of acute liver injury. (Hepatology 2017;65:616-630).

Notch pathway activation is essential for maintenance of stem-like cells in early tongue cancer

BACKGROUND

Notch pathway plays a complex role depending on cellular contexts: promotes stem cell maintenance or induces terminal differentiation in potential cancer-initiating cells; acts as an oncogene in lymphocytes and mammary tissue or plays a growth-suppressive role in leukemia, liver, skin, and head and neck cancer. Here, we present a novel clinical and functional significance of NOTCH1 alterations in early stage tongue squamous cell carcinoma (TSCC).

PATIENTS AND METHODS

We analyzed the Notch signaling pathway in 68 early stage TSCC primary tumor samples by whole exome and transcriptome sequencing, real-time PCR based copy number, expression, immuno-histochemical, followed by cell based biochemical and functional assays.

RESULTS

We show, unlike TCGA HNSCC data set, NOTCH1 harbors significantly lower frequency of inactivating mutations (4%); is somatically amplified; and, overexpressed in 31% and 37% of early stage TSCC patients, respectively. HNSCC cell lines over expressing NOTCH1, when plated in the absence of attachment, are enriched in stem cell markers and form spheroids. Furthermore, we show that inhibition of NOTCH activation by gamma secretase inhibitor or shRNA mediated knockdown of NOTCH1 inhibits spheroid forming capacity, transformation, survival and migration of the HNSCC cells suggesting an oncogenic role of NOTCH1 in TSCC. Clinically, Notch pathway activation is higher in tumors of non-smokers compared to smokers (50% Vs 18%, respectively, P=0.026) and is also associated with greater nodal positivity compared to its non-activation (93% Vs 64%, respectively, P=0.029).

CONCLUSION

We anticipate that these results could form the basis for therapeutic targeting of NOTCH1 in tongue cancer.

Early invasive fungal infections and colonization in patients with cirrhosis admitted to the intensive care unit

Bacterial infections in cirrhosis are common and associated with increased mortality, but little is known about fungal infections. The aim of this study, a sub-analysis of the Fungal Infection Risk Evaluation study, was to assess the incidence and implications of early invasive fungal disease (IFD) in patients with cirrhosis admitted to intensive care units (ICU). Clinical and laboratory parameters collected in the first 3 days of ICU stay for 782 patients with cirrhosis and/or portal hypertension were analysed and compared with those of 273 patients with very severe cardiovascular disease (CVD). The CVD patients had more co-morbidities and higher APACHE II scores. The overall incidence of IFD was similar in the two groups, but the incidence of IFD in ICU was higher in liver patients (1% versus 0.4%; p 0.025) as was fungal colonization (23.8% versus 13.9%; p 0.001). The ICU and in-hospital mortality, and length of stay were similar in the two groups. A higher proportion of liver patients received antifungal therapy (19.2% versus 7%; p <0.0005). There was no difference in mortality between colonized patients who received antifungal therapy and colonized patients who did not. The incidence of IFD in patients with cirrhosis in ICU is higher compared with another high-risk group, although it is still very low. This risk might be higher in patients with advanced liver disease admitted with acute-on-chronic liver failure, and this should be investigated further. Our data do not support prophylactic use of antifungal therapy in cirrhosis.

Abstract 4811: Pro-oncogenic role of NOTCH1 in early tongue squamous cell carcinoma

Notch pathway play a context-dependent tumor-suppressive or pro-oncogenic role in solid tumors and hematological malignancies. In head and neck cancer, inactivating mutations in NOTCH1 are associated with poor prognosis. Here we perform meta-analysis of DNA copy number and gene expression profiling of NOTCH signaling pathway genes in 35 paired primary T1 and T2 stage tongue tumors, comprising of Notch ligands, receptors and target genes. We find 32% of primary tongue squamous cell carcinoma (TSCC) tumors amplify NOTCH signaling pathway components; and over express activated NOTCH1based on immuno-histochemical staining in an additional series of 50 surgically resected paired TSCC tumors. Interestingly, these alterations: amplification at Notch ligand DLL3 (χ2 = 7.575, P = 0.023); over expression of Notch pathway target gene HEY2 transcript (χ2 = 9.885, P = 0.007); and expression of activated NOTCH1 (χ2 = 7.575, P = 0.023) positively correlate with N+ve and non- smoking status of patients. In a parallel effort, we characterized four HNSCC cell lines– NT8E, OT9, AW13516, and AW8507– established from Indian patients using whole exome, whole transcriptome sequencing and SNP array assays. Significant amplification and over expression of NOTCH signaling pathway components were observed in AW13516 and NT8E cells. Inhibition of NOTCH activation by gamma secretase inhibitor or shRNA mediated knockdown of NOTCH1 could inhibit transformation, survival, migration and invasion of NT8E cells. Taken together, we present that activation of Notch signaling pathway in a subset of TSCC patients is associated with nodal positivity and non-smoking status among early tongue cancer patients.

Citation Format: Pawan Upadhyay, Jyotirmoi Aich, Vidyalakshmi Sethunath, Prachi Dani, Sadhana Kannan, Pratik Chandrani, Kavitha Sonawane, Beamon Agarwal, Shubhada Kane, Sudhir Nair, Amit Dutt. Pro-oncogenic role of NOTCH1 in early tongue squamous cell carcinoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4811. doi:10.1158/1538-7445.AM2015-4811

Increasing NAD synthesis in muscle via nicotinamide phosphoribosyltransferase is not sufficient to promote oxidative metabolism

The NAD biosynthetic precursors nicotinamide mononucleotide and nicotinamide riboside are reported to confer resistance to metabolic defects induced by high fat feeding in part by promoting oxidative metabolism in skeletal muscle. Similar effects are obtained by germ line deletion of major NAD-consuming enzymes, suggesting that the bioavailability of NAD is limiting for maximal oxidative capacity. However, because of their systemic nature, the degree to which these interventions exert cell- or tissue-autonomous effects is unclear. Here, we report a tissue-specific approach to increase NAD biosynthesis only in muscle by overexpressing nicotinamide phosphoribosyltransferase, the rate-limiting enzyme in the salvage pathway that converts nicotinamide to NAD (mNAMPT mice). These mice display a ∼50% increase in skeletal muscle NAD levels, comparable with the effects of dietary NAD precursors, exercise regimens, or loss of poly(ADP-ribose) polymerases yet surprisingly do not exhibit changes in muscle mitochondrial biogenesis or mitochondrial function and are equally susceptible to the metabolic consequences of high fat feeding. We further report that chronic elevation of muscle NAD in vivo does not perturb the NAD/NADH redox ratio. These studies reveal for the first time the metabolic effects of tissue-specific increases in NAD synthesis and suggest that critical sites of action for supplemental NAD precursors reside outside of the heart and skeletal muscle.

Aging and sleep deprivation induce the unfolded protein response in the pancreas: implications for metabolism

Sleep disruption has detrimental effects on glucose metabolism through pathways that remain poorly defined. Although numerous studies have examined the consequences of sleep deprivation (SD) in the brain, few have directly tested its effects on peripheral organs. We examined several tissues in mice for induction of the unfolded protein response (UPR) following acute SD. In young animals, we found a robust induction of BiP in the pancreas, indicating an active UPR. At baseline, pancreata from aged animals exhibited a marked increase in a pro-apoptotic transcription factor, CHOP, that was amplified by SD, whereas BiP induction was not observed, suggesting a maladaptive response to cellular stress with age. Acute SD increased plasma glucose levels in both young and old animals. However, this change was not overtly related to stress in the pancreatic beta cells, as plasma insulin levels were not lower following acute SD. Accordingly, animals subjected to acute SD remained tolerant to a glucose challenge. In a chronic SD experiment, young mice were found to be sensitized to insulin and have improved glycemic control, whereas aged animals became hyperglycemic and failed to maintain appropriate plasma insulin concentrations. Our results show that both age and SD cooperate to induce the UPR in pancreatic tissue. While changes in insulin secretion are unlikely to play a major role in the acute effects of SD, CHOP induction in pancreatic tissues suggests that chronic SD may contribute to the loss or dysfunction of endocrine cells and that these effects may be exacerbated by normal aging.

Temporal effects of ethanol consumption on energy homeostasis, hepatic steatosis, and insulin sensitivity in mice

BACKGROUND

Alcoholic liver disease (ALD) progresses from steatosis to inflammation, fibrosis, and cirrhosis. Although ALD has been associated with insulin resistance, it is unclear whether insulin resistance coincides with the development of steatosis.

METHODS

We studied the temporal relationship of steatosis and glucose homeostasis in mice fed a Lieber-DeCarli liquid control or ethanol (EtOH) diet for 2, 4, or 8 weeks. We studied the effects of alcohol consumption on energy balance, body composition, and hepatic lipids. Glucose tolerance test was performed, and insulin sensitivity was evaluated with hyperinsulinemic-euglycemic clamp.

RESULTS

EtOH-fed mice developed hepatic steatosis over time as compared with control-fed mice despite similar energy intake and expenditure, and gain in body weight and fat. EtOH-fed mice developed glucose intolerance as early as 2 weeks, while insulin resistance developed at 4 weeks. A hyperinsulinemic clamp study at 8 weeks revealed both hepatic and peripheral insulin resistance in EtOH-fed mice. Insulin resistance was associated with hepatic steatosis, increased ceramide levels, and Perilipin 2 expression.

CONCLUSIONS

Chronic EtOH consumption leads to the development of hepatic steatosis, impaired glucose tolerance, and insulin resistance. These changes are independent of energy intake or expenditure, weight, whole body fat content, and inflammation. A better understanding of the processes linking EtOH-induced steatosis and abnormal glucose homeostasis may lead to novel therapies targeting the progression of ALD.

SIRT1 is required for AMPK activation and the beneficial effects of resveratrol on mitochondrial function

Resveratrol induces mitochondrial biogenesis and protects against metabolic decline, but whether SIRT1 mediates these benefits is the subject of debate. To circumvent the developmental defects of germline SIRT1 knockouts, we have developed an inducible system that permits whole-body deletion of SIRT1 in adult mice. Mice treated with a moderate dose of resveratrol showed increased mitochondrial biogenesis and function, AMPK activation, and increased NAD(+) levels in skeletal muscle, whereas SIRT1 knockouts displayed none of these benefits. A mouse overexpressing SIRT1 mimicked these effects. A high dose of resveratrol activated AMPK in a SIRT1-independent manner, demonstrating that resveratrol dosage is a critical factor. Importantly, at both doses of resveratrol no improvements in mitochondrial function were observed in animals lacking SIRT1. Together these data indicate that SIRT1 plays an essential role in the ability of moderate doses of resveratrol to stimulate AMPK and improve mitochondrial function both in vitro and in vivo.

Detection of isocyanates and polychlorinated biphenyls using proton transfer reaction mass spectrometry

RATIONALE

Isocyanates are highly reactive species widely used in industry. They can cause irritation of the eyes, trigger asthma, etc. Polychlorinated biphenyls (PCBs) were widely used in electrical equipments like capacitors and transformers in the last century and are still present in the environment today. PCBs are known to cause cancer and to affect the immune, reproductive, nervous and endocrine systems. Therefore, there is a need for a simple, rapid and reliable analytical method for the detection of traces of isocyanates and of PCBs.

METHODS

The data presented in this paper were obtained using a proton transfer reaction (PTR) time-of-flight mass spectrometer and a high sensitivity PTR quadrupole mass spectrometer. We also utilized a recently developed direct aqueous injection (DAI) inlet system for proton transfer reaction mass spectrometry (PTR-MS) instruments that allows the analysis of trace compounds in liquids.

RESULTS

We detected four isocyanates in the headspace above small sample quantities and investigated their fragmentation pathways to obtain a fundamental understanding of the processes involved in proton transfer reactions and also to determine the best operating conditions of the PTR-MS instruments. In addition, nine PCBs were unambiguously identified via their exact mass and isotopic distribution and detected in different concentration levels via direct injection of the liquid.

CONCLUSIONS

Utilizing recent developments and improvements in PTR-MS, we can rapidly detect two important environmental pollutant compound classes (isocyanates and PCBs) at high accuracy and without any sample preparation. In this paper, we provide proof of the detection of traces of isocyanates and PCBs in air and also of PCBs in liquids. These results could be used for the development of a real-time monitoring device for industrial waste, polluted air or water quality surveillance.

Use of proton transfer reaction time-of-flight mass spectrometry for the analytical detection of illicit and controlled prescription drugs at room temperature via direct headspace sampling

The first reported use of proton transfer reaction time-of-flight mass spectrometry (PTR-TOF-MS) for the detection of a range of illicit and prescribed drugs is presented here. We describe the capabilities of PTR-TOF-MS to detect the following commonly used narcotics-ecstasy (N-methyl-3,4-methylenedioxyamphetamine), morphine, codeine, cocaine and heroin-by the direct sampling of the headspace above small solid quantities (approximately 50 mg) of the drugs placed in glass vials at room temperature, i.e. with no heating of the sample and no pre-concentration. We demonstrate in this paper the ability to identify the drugs, both illicit and prescribed, using PTR-TOF-MS through the accurate m/z assignment of the protonated parent molecule to the second decimal place. We have also included in this study measurements with an impure sample of heroin, containing typical substances found in "street" heroin, to illustrate the use of the technology for more "real-world" samples. Therefore, in a real-world complex chemical environment, a high level of confidence can be placed on the detection of drugs. Although the protonated parent is observed for all drugs, the reactant channel leading to this species is not the only one observed and neither is it necessarily the most dominant. Details on the observed fragmentation behaviour are discussed and compared to electrospray ionisation MS(n) studies available in the literature.