Fluorinated tranylcypromine analogues as inhibitors of lysine-specific demethylase 1 (LSD1, KDM1A)

We report a series of tranylcypromine analogues containing a fluorine in the cyclopropyl ring. A number of compounds with additional m- or p-substitution of the aryl ring were micromolar inhibitors of the LSD1 enzyme. In cellular assays, the compounds inhibited the proliferation of acute myeloid leukemia cell lines. Increased levels of the biomarkers H3K4me2 and CD86 were consistent with LSD1 target engagement.     

Generation and functional characterization of anti-human and anti-mouse IL-36R antagonist monoclonal antibodies

Deficiency of interleukin (IL)-36 receptor antagonist (DITRA) syndrome is a rare autosomal recessive disease caused by mutations in IL36RN. IL-36R is a cell surface receptor and a member of the IL1R family that is involved in inflammatory responses triggered in skin and other epithelial tissues. Accumulating evidence suggests that IL-36R signaling may play a role in the pathogenesis of psoriasis. Therapeutic intervention of IL-36R signaling offers an innovative treatment paradigm for targeting epithelial cell-mediated inflammatory diseases such as the life-threatening psoriasis variant called generalized pustular psoriasis (GPP). We report the discovery and characterization of MAB92, a potent, high affinity anti-human IL-36 receptor antagonistic antibody that blocks human IL-36 ligand (α, β and γ)-mediated signaling. In vitro treatment with MAB92 directly inhibits human IL-36R-mediated signaling and inflammatory cytokine production in primary human keratinocytes and dermal fibroblasts. MAB92 shows exquisite species specificity toward human IL-36R and does not cross react to murine IL-36R. To enable in vivo pharmacology studies, we developed a mouse cross-reactive antibody, MAB04, which exhibits overlapping binding and pharmacological activity as MAB92. Epitope mapping indicates that MAB92 and MAB04 bind primarily to domain-2 of the human and mouse IL-36R proteins, respectively. Treatment with MAB04 abrogates imiquimod and IL-36-mediated skin inflammation in the mouse, further supporting an important role for IL-36R signaling in epithelial cell-mediated inflammation.     

The impact of natural products upon modern drug discovery

In the period 1970-2006, a total of 24 unique natural products were discovered that led to an approved drug. We analyze these successful leads in terms of drug-like properties, and show that they can be divided into two equal subsets. The first falls in the 'Lipinski universe' and complies with the Rule of Five. The second is a 'parallel universe' that violates the rules. Nevertheless, the latter compounds remain largely compliant in terms of logP and H-bond donors, highlighting the importance of these two metrics in predicting bioavailability. Natural products are often cited as an exception to Lipinski's rules. We believe this is because nature has learned to maintain low hydrophobicity and intermolecular H-bond donating potential when it needs to make biologically active compounds with high molecular weight and large numbers of rotatable bonds. In addition, natural products are more likely than purely synthetic compounds to resemble biosynthetic intermediates or endogenous metabolites, and hence take advantage of active transport mechanisms. Interestingly, the natural product leads in the Lipinski and parallel universe had an identical success rate (50%) in delivering an oral drug.     

Protective Effect of Betaine on Changes in the Levels of Membrane-bound ATPase activity and Mineral Status in Experimentally Induced Myocardial Infarction in Wistar Rats

Cardiovascular diseases are emerging as a major public health problem in most parts of the world even in developing countries still afflicted by infectious diseases, undernutrition, and other illnesses related to poverty. In the present study, we investigated the protective effect of betaine, a potent lipotropic molecule, on changes in the levels of membrane-bound ATPase activities, lipid peroxidation, sulfhydryl activities, and mineral status in isoprenaline-induced myocardial infarction in Wistar rats, an animal model of myocardial infarction in man. Oral administration of betaine (250 mg/kg body weight/day for a period of 30 days) significantly (p < 0.05) reduced the isoprenaline-induced abnormalities noted in the levels of sodium, potassium, and calcium in plasma and heart tissue. Pretreatment with betaine significantly attenuated isoprenaline-induced membrane-bound ATPase depletion in the heart tissue and preserved the myocardial membrane-bound ATPase activities at levels comparable to that of control rats. Oral administration of betaine significantly attenuated the isoprenaline-altered sulfhydryl groups in the heart tissue and preserved the myocardial sulfhydryl activities at levels comparable to that of control rats. It also significantly counteracted the isoprenaline-mediated lipid peroxidation and maintained the level at near normal. In the results of the present study, betaine administration significantly prevented the isoprenaline-induced alterations in the activities of membrane-bound ATPases, lipid peroxides, myocardial sulfhydryl levels, and maintained the mineral status at near normal.     

Removal of pattern-breaking sequences in microtubule binding repeats produces instantaneous tau aggregation and toxicity

Aggregated and highly phosphorylated tau protein is a pathological hallmark of Alzheimer's disease (AD) and other tauopathies. We identified motifs of alternating polar and apolar amino acids within the microtubule-binding repeats of tau which were interrupted by small breaking stretches. Minimal mutation of these breaking sequences yielded a unique instantly aggregating tau mutant containing longer stretches of polar/apolar amino acids without losing its microtubule-binding capacity. These modifications produced rapid aggregation and cytotoxicity with accompanying occurrence of pathologic tau phosphoepitopes (AT8, AT180, AT270, AT100, Ser(422), and PHF-1) and conformational epitopes (MC-1 and Alz50) in cells. Similar to pathological tau in the pretangle state, toxicity appeared to occur early without the requirement for extensive fibril formation. Thus, our mutant protein provides a novel platform for the investigation of the molecular mechanisms for toxicity and cellular behavior of pathologically aggregated tau proteins and the identification of its interaction partners.     

The tumor suppressor RASSF1A is a novel effector of small G protein Rap1A

Rap1A is a small G protein implicated in a spectrum of biological processes such as cell proliferation, adhesion, differentiation, and embryogenesis. The downstream effectors through which Rap1A mediates its diverse effects are largely unknown. Here we show that Rap1A, but not the related small G proteins Rap2 or Ras, binds the tumor suppressor Ras association domain family 1A (RASSF1A) in a manner that is regulated by phosphorylation of RASSF1A. Interaction with Rap1A is shown to influence the effect of RASSF1A on microtubule behavior.     

Phylogenetic diversity of rhizobia associated with horsegram [Macrotyloma uniflorum (Lam.) Verdc.] grown in South India based on glnII, recA and 16S-23S intergenic sequence analyses

Horsegram [Macrotyloma uniflorum (Lam.) Verdc.) is an important grain legume and fodder crop in India. Information on root nodule endosymbionts of this legume in India is limited. In the present study, 69 isolates from naturally occurring root nodules of horsegram collected from two agro-eco-climatic regions of South India was analyzed by generation rate, acid/alkali reaction on YMA medium, restriction fragment length polymorphism analysis of 16S-23S rDNA intergenic spacer region (IGS), and sequence analyses of IGS and housekeeping genes glnII and recA. Based on the rDNA IGS RFLP by means of three restriction enzymes rhizobia were grouped in five clusters (I–V). By sequence analysis of 16S-23S rDNA IGS identified genotypes of horsegram rhizobia were distributed into five divergent lineages of Bradyrhizobium genus which comprised (I) the IGS type IV rhizobia and valid species B. yuanmingense, (II) the strains of IGS type I and Bradyrhizobium sp. ORS 3257 isolated from Vigna sp., (III) the strains of the IGS type II and Bradyrhizobium sp. CIRADAc12 from Acacia sp., (IV) the IGS type V strains and Bradyrhizobium sp. genospecies IV, and (V) comprising genetically distinct IGS type III strains which probably represent an uncharacterized new genomic species. Nearly, 87% of indigenous horsegram isolates (IGS types I, II, III, and V) could not be related to any other species within the genus Bradyrhizobium. Phylogeny based on housekeeping glnII and recA genes confirmed those results found by the analysis of the IGS sequence. All the isolated rhizobia nodulated Macrotyloma sp. and Vigna spp., and only some of them formed nodules on Arachis hypogeae. The isolates within each IGS type varied in their ability to fix nitrogen. Selection for high symbiotic effective strains could reward horsegram production in poor soils of South India where this legume is largely cultivated.     

Behavioral responses and bioefficacy of some aromatic amides against Aedes aegypti

A series of substituted aromatic amides by varying the chain length, substitution of methyl, methoxy, chloro, and fluoro groups at ortho-, meta-, and para-positions of the phenyl ring of N,N-diethyl-2-phenylacetamide were synthesized. Laboratory studies were carried out to observe the behavioral responses and repellent activity of these newly synthesized aromatic amides against Aedes aegypti (L.) mosquitoes. The deterrent activity of these synthetic amides against any vectors has not been reported previously. These aromatic amides were tested for their behavioral responses and compared with the well known insect repellents, namely, N,N-diethyl toluamide; N,N-diethyl phenylacetamide; and N,N-diethylbenzamide. Out of the 14 compounds synthesized, seven compounds were selected on the basis of those showing >75% of repellent response for the bioefficacy test on human volunteers. The potential use of lead compounds in personal protection management is discussed.