Discovery of small-molecule natural products that target cellular bioenergetics

Molecular-targeted antitumor therapy has found favor in antitumor drug discovery programs. Hypoxia (\u3c 5% oxygen) is a comfeature of solid tumors and hypoxia-inducible factor-1 (HIF-1) represents an important antitumor target. Bioenergetic homeostasis is typically altered in tumor cells and HIF-1 plays an important role to produce a glycolytic phenotype. Glycolysis inhibitors are an emerging class of potential tumor-selective adjuvant therapeutic agents. Natural product aerobic glycolysis inhibitors may enhance the effectiveness of current therapies. Mitochondrial oxidative phosphorylation inhibitors in botanical dietary supplements (BDS) possess a potential health hazard which should be identified and appropriately regulated. Chapter one briefly reviews the molecular-targeted natural product antitumor drug discovery process. Descriptions of tumor hypoxia, HIF-1, HIF-1 regulatory pathways and the effect of HIF-1 on tumor cell bioenergetics are presented. Cellular bioenergetic pathways and natural products that inhibit HIF-1 by interfering with cellular bioenergetics are discussed. Mitochondriotoxic small-molecule natural products reported previously are further reviewed. Chapter two discusses the effect of chromatographic media on molecular-targeted antitumor drug discovery. A panel of crude extracts was eluted through columns of various chromatographic media using a step gradient method. Total recoveries from the various columns and various elution protocols were compared and statistically analyzed. The crude extracts and column eluates were evaluated for HIF-1 inhibitory activity. Chapter three discusses the development of a bioenergetics-based screening method to screen crude extracts for glycolysis inhibitors. Crude extracts (10,648) were screened and seven hits (hit rate 0.72%) were identified. Bioassay-guided isolation of Moronobea coccinea crude extract resulted in isolation of a protonophoric compound moronone (1) (false positive). The structure of 1 was determined by a combination of spectroscopic and spectrometric means. The protonophoric compounds must be rapidly dereplicated for successful discovery of glycolysis inhibitors. Chapter four discusses the screening of BDS products and pure compounds for mitochondrial uncouplers or electron transport chain inhibitors. The blue cohosh (Caulophyllum thalictroides) extract and three saponins cauloside A (3), saponin PE (4) and cauloside C (5) permeabilize the mitochondrial membrane. Sesamin (6) and guggulsterol III (7) and guggul (Commiphora wightii) extract inhibit mitochondrial complex I. These extracts and compounds are cytotoxic in nature

Incidence and outcome of no flow after primary percutaneous coronary intervention in acute myocardial infarction

  Background: Mechanical revascularization of the infarct-related artery (IRA) is the most effective treatment modality in ST-segment elevation myocardial infarction (STEMI).No flow occurs in ∼8.8-10% of cases of primary percutaneous coronary intervention(PCI) in STEMI patients. Our aim was to study     actual incidence and outcome of no flow patients. Methods: Five hundred and eighty primary PCI patients were studied over a period of two years i.e. January 2016 to December 2017. Drug eluting stents were used in all cases. Majority of our patients(>90%) came  6 hours  after onset of chest pain. There were many patients where there was  no flow even after mechanical thrombus aspiration and pharmacological vasodilator therapy. We have studied primary outcome(mortality) of no flow in those patients.                                                                                                                 Results: There were 44 cases of  no flow in our series(7.75%). Left anterior descending artery(LAD )was involved in eighteen patients. Right coronary artery(RCA) was culprit in twenty four cases. Only two cases were seen in LCX territory. One month mortality rate in no flow group was 50% and 6.25% in successful recanalization group. One year mortality was 12.5% in successful recanalization group and 66% in no flow group. Conclusion: Refractory no flow during primary PCI in STEMI is associated with high mortality and morbidity. There is no established strategy to solve this phenomenon.   &nbsp

PPARα-targeted mitochondrial bioenergetics mediate repair of intestinal barriers at the host-microbe intersection during SIV infection.

Chronic gut inflammatory diseases are associated with disruption of intestinal epithelial barriers and impaired mucosal immunity. HIV-1 (HIV) causes depletion of mucosal CD4+ T cells early in infection and disruption of gut epithelium, resulting in chronic inflammation and immunodeficiency. Although antiretroviral therapy (ART) is effective in suppressing viral replication, it is incapable of restoring the "leaky gut," which poses an impediment for HIV cure efforts. Strategies are needed for rapid repair of the epithelium to protect intestinal microenvironments and immunity in inflamed gut. Using an in vivo nonhuman primate intestinal loop model of HIV/AIDS, we identified the pathogenic mechanism underlying sustained disruption of gut epithelium and explored rapid repair of gut epithelium at the intersection of microbial metabolism. Molecular, immunological, and metabolomic analyses revealed marked loss of peroxisomal proliferator-activated receptor-α (PPARα) signaling, predominant impairment of mitochondrial function, and epithelial disruption both in vivo and in vitro. To elucidate pathways regulating intestinal epithelial integrity, we introduced probiotic Lactobacillus plantarum into Simian immunodeficiency virus (SIV)-inflamed intestinal lumen. Rapid recovery of the epithelium occurred within 5 h of L. plantarum administration, independent of mucosal CD4+ T cell recovery, and in the absence of ART. This intestinal barrier repair was driven by L. plantarum-induced PPARα activation and restoration of mitochondrial structure and fatty acid β-oxidation. Our data highlight the critical role of PPARα at the intersection between microbial metabolism and epithelial repair in virally inflamed gut and as a potential mitochondrial target for restoring gut barriers in other infectious or gut inflammatory diseases

Fabrication of 108^{108}Cd target for the astrophysical p-process studies

The detailed process of preparing enriched $^{108}$Cd targets on mylar and copper backing using the vacuum evaporation technique is described. These targets were employed in an experiment to measure the proton capture cross-section at energies significantly below the Coulomb barrier, for the astrophysical p-process studies. Due to the low melting point and high vapor pressure of cadmium, some adjustments were implemented in the Telemark multipocket e-beam setup. The target thickness was determined through the measurement of alpha particle energy loss from a triple alpha source and also by RBS measurements. The thickness of the $^{108}$Cd films varies between 290 to 660 $\mu$g/cm$^2$, with a non-uniformity of approximately 10$\%$. X-ray Photoelectron Spectroscopy (XPS) and X-ray Fluorescence (XRF) analyses were conducted to examine the presence of impurities and to assess surface morphology, phase, and chemical composition

A Rank-Sum Test for Clustered Data When the Number of Subjects in a Group within a Cluster is Informative

PLENARY LECTURE

Temporal prediction of future state occupation in a multistate model from high-dimensional baseline covariates via pseudo-value regression

<p>In many complex diseases such as cancer, a patient undergoes various disease stages before reaching a terminal state (say disease free or death). This fits a multistate model framework where a prognosis may be equivalent to predicting the state occupation at a future time <i>t</i>. With the advent of high-throughput genomic and proteomic assays, a clinician may intent to use such high-dimensional covariates in making better prediction of state occupation. In this article, we offer a practical solution to this problem by combining a useful technique, called pseudo-value (PV) regression, with a latent factor or a penalized regression method such as the partial least squares (PLS) or the least absolute shrinkage and selection operator (LASSO), or their variants. We explore the predictive performances of these combinations in various high-dimensional settings via extensive simulation studies. Overall, this strategy works fairly well provided the models are tuned properly. Overall, the PLS turns out to be slightly better than LASSO in most settings investigated by us, for the purpose of temporal prediction of future state occupation. We illustrate the utility of these PV-based high-dimensional regression methods using a lung cancer data set where we use the patients’ baseline gene expression values.</p