pyrazolopyridine and Disease-Models--Animal

To identify phosphodiesterase-9 (PDE9) as a novel target for the treatment of vascular dementia (VaD), a series of pyrazolopyrimidinone analogues were discovered based on a hit 1. Hit-to-lead optimization resulted in a potent inhibitor 2 with excellent selectivity and physicochemical properties to enable in vivo studies. Oral administration of 2 (5.0 mg/kg) caused notable therapeutic effects in the VaD mouse model, providing a promising lead or chemical probe for investigating the biological functions of PDE9 inhibition.

Topics: 3',5'-Cyclic-AMP Phosphodiesterases; Administration, Oral; Animals; Binding Sites; Catalytic Domain; Dementia, Vascular; Disease Models, Animal; Drug Design; Drug Evaluation, Preclinical; Half-Life; Humans; Maze Learning; Mice; Molecular Docking Simulation; Phosphodiesterase Inhibitors; Protein Isoforms; Pyrazoles; Pyridines; Rats; Rats, Sprague-Dawley; Structure-Activity Relationship

In order to discover novel anti-inflammatory agents for treatment of arthritis and based on preliminary structure-activity relationships, four series (A-D) of total 90 new pyrazolo[4,3- d]pyrimidine compounds were designed and synthesized. All the compounds have been tested for their anti-inflammatory activities by inhibiting of LPS-induced NO production. A clear structure-activity relationship has been concluded step by step, and finally 3,4,5-trimethoxystyryl-1 H-pyrazolo[4,3- d]pyrimidine was found to be the most active scaffold. Among them, compound D27 was discovered as the most potent anti-inflammatory agent (IC

Topics: Animals; Anti-Inflammatory Agents; Arthritis, Experimental; Crystallography, X-Ray; Dimerization; Disease Models, Animal; Drug Design; Enzyme Inhibitors; Interleukin-1beta; Lipopolysaccharides; Macrophages; Mice; Molecular Conformation; Nitric Oxide; Nitric Oxide Synthase Type II; Pyrazoles; Pyridines; Rats; RAW 264.7 Cells; Structure-Activity Relationship

Diarrhoeal disease is responsible for 8.6% of global child mortality. Recent epidemiological studies found the protozoan parasite Cryptosporidium to be a leading cause of paediatric diarrhoea, with particularly grave impact on infants and immunocompromised individuals. There is neither a vaccine nor an effective treatment. Here we establish a drug discovery process built on scalable phenotypic assays and mouse models that take advantage of transgenic parasites. Screening a library of compounds with anti-parasitic activity, we identify pyrazolopyridines as inhibitors of Cryptosporidium parvum and Cryptosporidium hominis. Oral treatment with the pyrazolopyridine KDU731 results in a potent reduction in intestinal infection of immunocompromised mice. Treatment also leads to rapid resolution of diarrhoea and dehydration in neonatal calves, a clinical model of cryptosporidiosis that closely resembles human infection. Our results suggest that the Cryptosporidium lipid kinase PI(4)K (phosphatidylinositol-4-OH kinase) is a target for pyrazolopyridines and that KDU731 warrants further preclinical evaluation as a drug candidate for the treatment of cryptosporidiosis.

Topics: 1-Phosphatidylinositol 4-Kinase; Animals; Animals, Newborn; Cattle; Cell Line, Tumor; Cryptosporidiosis; Cryptosporidium; Disease Models, Animal; Female; Humans; Immunocompromised Host; Interferon-gamma; Male; Mice; Mice, Knockout; Pyrazoles; Pyridines; Rats; Rats, Wistar

Nitric oxide (NO) is a widespread, potent, biological mediator that has many physiological and pathophysiological roles. Research in the field of NO appears to have followed a straightforward path, and the findings have been progressive: NO and cyclic GMP are involved in vasodilatation; glycerol trinitrate relaxes vascular smooth muscles by bioconversion to NO; mammalian cells synthesize NO; and last, NO mediates vasodilatation by stimulating the soluble guanylate cyclase (sGC), a heterodimeric (alpha/beta) haem protein that converts GTP to cGMP2-4. Here we report the discovery of a regulatory site on sGC. Using photoaffinity labelling, we have identified the cysteine 238 and cysteine 243 region in the alpha1-subunit of sGC as the target for a new type of sGC stimulator. Moreover, we present a pyrazolopyridine, BAY 41-2272, that potently stimulates sGC through this site by a mechanism that is independent of NO. This results in antiplatelet activity, a strong decrease in blood pressure and an increase in survival in a low-NO rat model of hypertension, and as such may offer an approach for treating cardiovascular diseases.

Topics: Amino Acid Sequence; Animals; Antihypertensive Agents; Binding Sites; Blood Pressure; Cyclic N-Oxides; Cysteine; Disease Models, Animal; Enzyme Activation; Female; Guanylate Cyclase; Heme; Humans; Imidazoles; In Vitro Techniques; Indazoles; Molecular Sequence Data; Nitric Oxide; Photoaffinity Labels; Platelet Aggregation Inhibitors; Pyrazoles; Pyridines; Rats; Solubility