Inhibitor of CBP Histone Acetyltransferase Downregulates p53 Activation and Facilitates Methylation at Lysine 27 on Histone H3.

Tumor suppressor p53-directed apoptosis triggers loss of normal cells, which contributes to the side-effects from anticancer therapies. Thus, small molecules with potential to downregulate the activation of p53 could minimize pathology emerging from anticancer therapies. Acetylation of p53 by the histone acetyltransferase (HAT) domain is the hallmark of coactivator CREB-binding protein (CBP) epigenetic function. During genotoxic stress, CBP HAT-mediated acetylation is essential for the activation of p53 to transcriptionally govern target genes, which control cellular responses. Here, we present a small molecule, NiCur, which blocks CBP HAT activity and downregulates p53 activation upon genotoxic stress. Computational modeling reveals that NiCur docks into the active site of CBP HAT. On CDKN1A promoter, the recruitment of p53 as well as RNA Polymerase II and levels of acetylation on histone H3 were diminished by NiCur. Specifically, NiCur reduces the levels of acetylation at lysine 27 on histone H3, which concomitantly increases the levels of trimethylation at lysine 27. Finally, NiCur attenuates p53-directed apoptosis by inhibiting the Caspase 3 activity and cleavage of Poly (ADP-ribose) polymerase (PARP) in normal gastrointestinal epithelial cells. Collectively, NiCur demonstrates the potential to reprogram the chromatin landscape and modulate biological outcomes of CBP-mediated acetylation under normal and disease conditions.

Anthrax SET protein: a potential virulence determinant that epigenetically represses NF-κB activation in infected macrophages.

Toxins play a major role in the pathogenesis of Bacillus anthracis by subverting the host defenses. However, besides toxins, B. anthracis expresses effector proteins, whose role in pathogenesis are yet to be investigated. Here we present that suppressor-of-variegation, enhancer-of-zeste, trithorax protein from B. anthracis (BaSET) methylates human histone H1, resulting in repression of NF-κB functions. Notably, BaSET is secreted and undergoes nuclear translocation to enhance H1 methylation in B. anthracis-infected macrophages. Compared with wild type Sterne, delayed growth kinetics and altered septum formation were observed in the BaSET knock-out (BaΔSET) bacilli. Uncontrolled BaSET expression during complementation of the BaSET gene in BaΔSET partially restored growth during stationary phase but resulted in substantially shorter bacilli throughout the growth cycle. Importantly, in contrast to Sterne, the BaΔSET B. anthracis is avirulent in a lethal murine bacteremia model of infection. Collectively, BaSET is required for repression of host transcription as well as proper B. anthracis growth, making it a potentially unique virulence determinant.

Neuroprotective effects of linagliptin in a rotenone-induced rat model of Parkinson's disease.

The present study investigates the antiParkinsonian activity of dipeptidyl peptidase-4 (DPP-IV) inhibitor, linagliptin. The experimental Parkinson's disease (PD) was induced by administration of rotenone at a dose of 1.5 mg/kg at alternate day subcutaneously for 21 days. Standard drug (levodopa-200 mg/kg and carbidopa-50 mg/kg) and treatment drug (linagliptin-5 mg/kg, 10 mg/kg, and 20mg/kg) were administered orally daily 1 h before rotenone administration. In a rat rotenone model, linagliptin improved muscle coordination, motor performance, and corrected akinesia. Pretreatment with linagliptin showed significant higher levels of superoxide dismutase, catalase, and glutathione in brain homogenate of animals. Linagliptin significantly elevated the levels of striatal DA and active glucagon-like peptide 1 in brain homogenate of animals. Furthermore, linagliptin amended alterations induced by rotenone in the thiobarbituric acid reactive substances and inflammatory marker such as tumor necrosis factor-α level. The results of the present study indicate the neuroprotective potential of linagliptin for the management of PD might be due to remarkable improvement in motor functions, antioxidant, anti-inflammatory, anti-apoptotic, and neuroprotective mechanisms.

Acute Severe Seronegative Autoimmune Hepatitis With Undiagnosed Graves' Disease.

Autoimmune hepatitis (AIH) is a progressive inflammatory condition hypothesized to be a T-lymphocyte (T-cell)-mediated immune response that commonly affects females more than males. Given its proposed mechanism associated with immune response, it is more likely to present with other autoimmune conditions, particularly autoimmune disorders associated with the thyroid. AIH can be difficult to diagnose as it is a diagnosis of exclusion. AIH lacks validated algorithms for proper diagnosis and can seldom present with negative antibodies. If not fully worked up, AIH may progress to cirrhosis and even increase the risk of malignancy. Therefore, a liver biopsy is a crucial step in the workup for AIH. We report a rare case of acute severe AIH associated with negative antibodies and undiagnosed Graves' disease.

Rational design of cyclic peptide modulators of the transcriptional coactivator CBP: a new class of p53 inhibitors.

The CREB binding protein (CBP) is a human transcriptional coactivator consisting of several conserved functional modules, which interacts with distinct transcription factors including nuclear receptors, CREB, and STAT proteins. Despite the importance of CBP in transcriptional regulation, many questions regarding the role of its particular domains in CBP functions remain unanswered. Therefore, developing small molecules capable of selectively modulating a single domain of CBP is of invaluable aid at unraveling its prominent activities. Here we report the design, synthesis, and biological evaluation of conformationally restricted peptides as novel modulators for the acetyl-lysine binding bromodomain (BRD) of CBP. Utilizing a target structure-guided and computer-aided rational design approach, we developed a series of cyclic peptides with affinity for CBP BRD significantly greater than those of its biological ligands, including lysine-acetylated histones and tumor suppressor p53. The best cyclopeptide of the series exhibited a K(d) of 8.0 µM, representing a 24-fold improvement in affinity over that of the linear lysine 382-acetylated p53 peptide. This lead peptide is highly selective for CBP BRD over BRDs from other transcriptional proteins. Cell-based functional assays carried out in colorectal carcinoma HCT116 cells further demonstrated the efficacy of this compound to modulate p53 stability and function in response to DNA damage. Our results strongly argue that these CBP modulators can effectively inhibit p53 transcriptional activity by blocking p53K382ac binding to CBP BRD and promoting p53 instability by changes of its post-translational modification states, a different mechanism than that of the p53 inhibitors reported to date.

Diagnosis and management of Crohn's disease.

Crohn's disease is a chronic inflammatory condition affecting the gastrointestinal tract at any point from the mouth to the rectum. Patients may experience diarrhea, abdominal pain, fever, weight loss, abdominal masses, and anemia. Extraintestinal manifestations of Crohn's disease include osteoporosis, inflammatory arthropathies, scleritis, nephrolithiasis, cholelithiasis, and erythema nodosum. Acute phase reactants, such as C-reactive protein level and erythrocyte sedimentation rate, are often increased with inflammation and may correlate with disease activity. Levels of vitamin B12, folate, albumin, prealbumin, and vitamin D can help assess nutritional status. Colonoscopy with ileoscopy, capsule endoscopy, computed tomography enterography, and small bowel follow-through are often used to diagnose Crohn's disease. Ultrasonography, computed axial tomography, scintigraphy, and magnetic resonance imaging can assess for extraintestinal manifestations or complications (e.g., abscess, perforation). Mesalamine products are often used for the medical management of mild to moderate colonic Crohn's disease. Antibiotics (e.g., metronidazole, fluoroquinolones) are often used for treatment. Patients with moderate to severe Crohn's disease are treated with corticosteroids, azathioprine, 6-mercaptopurine, or anti-tumor necrosis factor agents (e.g., infliximab, adalimumab). Severe disease may require emergent hospitalization and a multidisciplinary approach with a family physician, gastroenterologist, and surgeon.

A Case of Immune Thrombocytopenia After COVID-19 Infection.

Immune thrombocytopenia (ITP) is a hematological condition that is characterized by a low platelet count. ITP can be primary or secondary. Secondary causes are diverse and include viral infections. The novel coronavirus has rarely been recognized as cause of ITP. This is a case of an 82-year-old Caucasian male who was infected by the novel coronavirus four weeks prior. His platelet count on admission was 1,000/mm3. He was diagnosed with ITP caused by the novel coronavirus as there were no other causes for his thrombocytopenia. The patient was treated with platelet infusions, high-dose corticosteroids, and intravenous immunoglobulin infusions.

The Reemergence of Specialty Pharmacy.

Twenty years ago, the Journal of Managed Care & Specialty Pharmacy published an article titled "The Emergence of Specialty Pharmacy." While the industry was in its relative infancy at the time, the specialty pharmacy model has since grown, expanded, and matured, largely following some of the trends outlined at the time. Now, with changes in legislation, a progressive approach within the FDA, a second coming of novel therapies and supplemental indications, along with an involvement in cell and gene therapy, a reemergence of the specialty model is taking place, and the market must adapt to the new challenges associated with this era of modern medicine. DISCLOSURES: No funding contributed to the writing of this article. Ogurchak reports speaker fees from MJH Live Events and WellSky, unrelated to this work. The other authors have nothing to disclose with respect to research, authorship, and/or publication of this article.

Hydrogen peroxide improves the visibility of ulcer bases in acute non-variceal upper gastrointestinal bleeding: a single-center prospective study.

BACKGROUND: Acute non-variceal upper gastrointestinal bleeding (ANVB) or hemorrhage (used interchangeably) is an emergency. Endoscopically applied hydrogen peroxide (H2O2) has been shown to improve visualization of the ulcer base. AIMS: To test the hypothesis that ulcer base clot clearance with 3% H2O2 improves the visualization of ANVB lesions compared to water alone. METHODS: In this single-center prospective study, 320 patients with ANVB were examined, of which 81 met the entry criteria for evaluation. All patients with ANVB underwent urgent endoscopy. Those with adherent clots on the ulcer base were sprayed with 250 ml of water, followed by up to 100 ml of 3% H2O2. The main outcome measurement was Kalloo"s Visual Scores of the ulcer base before and after water and H2O2. RESULTS: Eighty-one patients with gastric ulcers (GU; 34) and duodenal ulcers (DU; 47) met the entry criteria. The mean improvement in grade from water to H2O2 was 2.04 (95% confidence interval [CI] (1.86, 2.23)). The mean volume of H2O2 used to clear clots was higher (70 ml) in patients who were negative for both Helicobacter pylori and non-steroidal anti-inflammatory drug (NSAID) use than in those who were positive for both (31 ml) (P = 0.00). More DU patients (72%) had visible vessels than GU patients (44%) (P = 0.01). CONCLUSIONS: H2O2 improved the visualization of ulcer bases in ANVB. A smaller volume of H2O2 was required to clear clots in patients who used NSAIDs and had H. pylori infection. H2O2 identified more DU vessels. The use of H2O2 should be considered as a standard therapy in the management of clots in ANVB.

Protective effects of the carotenoid zeaxanthin in experimental nonalcoholic steatohepatitis.

Fat infiltration and inflammation cause liver injury and fibrosis and may progress to nonalcoholic steatohepatitis (NASH) and end-stage liver disease. Currently, there are no effective treatments for NASH. Zeaxanthin is a carotenoid which has been shown to be preferentially accumulated in the adipose tissue and liver. We hypothesized that treatment with zeaxanthin may decrease oxidative stress in the liver and, possibly, halt the inflammation and fibrosis associated with NASH. Here we tested zeaxanthin effects in preventing progression of liver injury in a model of NASH. Mongolian gerbils, fed a methionine-choline-deficient diet, were treated with different doses of zeaxanthin. We assessed histopathological changes by hematoxylin-eosin and Masson trichrome staining and determined oxidative stress by measuring lipid peroxidation. The obtained results show that zeaxanthin significantly prevented NASH progression by decreasing oxidative stress and liver fibrosis, thus suggesting a potential therapeutic application for this carotenoid in the management of NASH.

Safety, tolerability, pharmacokinetics, and pharmacodynamics of compound SFDAC by intranasal administration of multiple escalating dose in healthy male subjects.

A novel corticosteroid compound (short form of IUPAC name: SFDAC) has been discovered by Sun Pharma Advanced Research Company (SPARC) Ltd. A randomized, observer-blind, active-controlled, parallel-groups, intranasal multiple escalating dose study was conducted in healthy male subjects to assess safety, tolerability, pharmacokinetics, and pharmacodynamics of compound SFDAC formulated as an aqueous suspension for intranasal administration. Intranasal sprays of SFDAC, active control fluticasone propionate (FP) and placebo were administered once in a day for 14 days as per randomization. Various clinical evaluations including 24-hour serum cortisol and urinary free cortisol (UFC) profiles were carried out. Blood samples were collected at pre-defined time-points and analyzed using a validated chromatographic method for estimation of SFDAC and its metabolite. The results of the study indicate that multiple dose of SFDAC intranasal spray upto 3,200 µg is safe and tolerated. Clinically significant suppression of hypothalamic pituitary adrenal (HPA) axis was not observed. The plasma concentration of SFDAC was found to be below the lower limit of quantification (LLQ) at most time-points for all subjects. SFDAC M1 metabolite was detected only at picogram level in plasma. The safety and pharmacokinetic characteristics of SFDAC observed in this study support further clinical development of the SFDAC nasal spray.

Science of the science, drug discovery and artificial neural networks.

Drug discovery process many times encounters complex problems, which may be difficult to solve by human intelligence. Artificial Neural Networks (ANNs) are one of the Artificial Intelligence (AI) technologies used for solving such complex problems. ANNs are widely used for primary virtual screening of compounds, quantitative structure activity relationship studies, receptor modeling, formulation development, pharmacokinetics and in all other processes involving complex mathematical modeling. Despite having such advanced technologies and enough understanding of biological systems, drug discovery is still a lengthy, expensive, difficult and inefficient process with low rate of new successful therapeutic discovery. In this paper, author has discussed the drug discovery science and ANN from very basic angle, which may be helpful to understand the application of ANN for drug discovery to improve efficiency.

Protein kinase C inhibitors: a patent review (2010 - present).

INTRODUCTION: Protein kinase C (PKC) comprises at least 10 isoforms, pivotal in various cellular differentiation processes and in other specific cellular functions. Catalytic subunits of all PKCs are highly conserved which play a central role in the development of kinase-specific inhibitors for the treatment of a number of diseases and also in the drug resistance and immunological disorders. The authors' previous work of reviewing patents of PKC inhibitors is continued in this report. AREA COVERED: Thorough survey on the physiological roles of PKC isoforms and patents filed for PKC inhibitors from 2010 to present representing new and potential strategy for the cure and prevention of disorders due to elevation in various PKC levels is reported. EXPERT OPINION: The PKC isoforms are unique in terms of tissue distribution and an elevation in any isoform level results in different diseased conditions. Different PKC isoforms have high sequence identity but they are involved in different diseases. Crystal structure of few PKC isoforms viz. C1 domain of PKCδ, the C2 domains of PKCα and ß, kinase domain and full structure of PKCßII are known. Identification of more crystal structures and thorough analysis of available structures and information on the PKC ligands will be helpful in the drug designing and development processes.

Protein kinase C inhibitors: a patent review (2008 - 2009).

INTRODUCTION: The protein kinase C (PKC) is a family of multifunctional isoenzymes involved in apoptosis, migration, adhesion, tumorgenesis, cardiac hypertrophy, angiogenesis, platelet function and inflammation. It also plays a vital role in the regulation of signal transduction, cell proliferation and differentiation through positive and negative regulation of the cell cycle. In this work, we reviewed the existing PKC inhibitors and several patents linked to PKC inhibitors. AREAS COVERED: Thorough survey on the PKC inhibitors having clinical importance and patents filed for these inhibitors from 2008 - 2009 is reported. EXPERT OPINION: PKCs are highly potential therapeutic targets for treating diabetic complications, oncological, inflammatory, immunological and dermatological disorders. The clinical trial candidates of PKCs mainly target the catalytic domain, which is highly conserved throughout the PKC family making it difficult to target a particular isoform selectively. Relatively less chemical space and fewer bisubstrate inhibitors targeting both ATP and regulatory domain are explored for PKCs, more research in these areas will be helpful in overcoming existing problems.

The biology of lysine acetylation integrates transcriptional programming and metabolism.

The biochemical landscape of lysine acetylation has expanded from a small number of proteins in the nucleus to a multitude of proteins in the cytoplasm. Since the first report confirming acetylation of the tumor suppressor protein p53 by a lysine acetyltransferase (KAT), there has been a surge in the identification of new, non-histone targets of KATs. Added to the known substrates of KATs are metabolic enzymes, cytoskeletal proteins, molecular chaperones, ribosomal proteins and nuclear import factors. Emerging studies demonstrate that no fewer than 2000 proteins in any particular cell type may undergo lysine acetylation. As described in this review, our analyses of cellular acetylated proteins using DAVID 6.7 bioinformatics resources have facilitated organization of acetylated proteins into functional clusters integral to cell signaling, the stress response, proteolysis, apoptosis, metabolism, and neuronal development. In addition, these clusters also depict association of acetylated proteins with human diseases. These findings not only support lysine acetylation as a widespread cellular phenomenon, but also impel questions to clarify the underlying molecular and cellular mechanisms governing target selectivity by KATs. Present challenges are to understand the molecular basis for the overlapping roles of KAT-containing co-activators, to differentiate between global versus dynamic acetylation marks, and to elucidate the physiological roles of acetylated proteins in biochemical pathways. In addition to discussing the cellular 'acetylome', a focus of this work is to present the widespread and dynamic nature of lysine acetylation and highlight the nexus that exists between epigenetic-directed transcriptional regulation and metabolism.

A small molecule binding to the coactivator CREB-binding protein blocks apoptosis in cardiomyocytes.

As a master transcription factor in cellular responses to external stress, tumor suppressor p53 is tightly regulated. Excessive p53 activity during myocardial ischemia causes irreversible cellular injury and cardiomyocyte death. p53 activation is dependent on lysine acetylation by the lysine acetyltransferase and transcriptional coactivator CREB-binding protein (CBP) and on acetylation-directed CBP recruitment for p53 target gene expression. Here, we report a small molecule ischemin, developed with a structure-guided approach to inhibit the acetyl-lysine binding activity of the bromodomain of CBP. We show that ischemin alters post-translational modifications on p53 and histones, inhibits p53 interaction with CBP and transcriptional activity in cells, and prevents apoptosis in ischemic cardiomyocytes. Our study suggests small molecule modulation of acetylation-mediated interactions in gene transcription as a new approach to therapeutic interventions of human disorders such as myocardial ischemia.

Applications of artificial neural networks in medical science.

Computer technology has been advanced tremendously and the interest has been increased for the potential use of 'Artificial Intelligence (AI)' in medicine and biological research. One of the most interesting and extensively studied branches of AI is the 'Artificial Neural Networks (ANNs)'. Basically, ANNs are the mathematical algorithms, generated by computers. ANNs learn from standard data and capture the knowledge contained in the data. Trained ANNs approach the functionality of small biological neural cluster in a very fundamental manner. They are the digitized model of biological brain and can detect complex nonlinear relationships between dependent as well as independent variables in a data where human brain may fail to detect. Nowadays, ANNs are widely used for medical applications in various disciplines of medicine especially in cardiology. ANNs have been extensively applied in diagnosis, electronic signal analysis, medical image analysis and radiology. ANNs have been used by many authors for modeling in medicine and clinical research. Applications of ANNs are increasing in pharmacoepidemiology and medical data mining. In this paper, authors have summarized various applications of ANNs in medical science.