Orlistat response to missense mutations in lipoprotein lipase

Facilitating the drug repurposing with iC/E strategy: A practice on novel nNOS inhibitor discovery

Over the past decades, many existing drugs and clinical/preclinical compounds have been repositioned as new therapeutic indication from which they were originally intended and to treat off-target diseases by targeting their noncognate protein receptors, such as Sildenafil and Paxlovid, termed drug repurposing (DRP). Despite its significant attraction in the current medicinal community, the DRP is usually considered as a matter of accidents that cannot be fulfilled reliably by traditional drug discovery protocol. In this study, we proposed an integrated computational/experimental (iC/E) strategy to facilitate the DRP within a framework of rational drug design, which was practiced on the identification of new neuronal nitric oxide synthase (nNOS) inhibitors from a structurally diverse, functionally distinct drug pool. We demonstrated that the iC/E strategy is very efficient and readily feasible, which confirmed that the phosphodiesterase inhibitor DB06237 showed a high inhibitory potency against nNOS synthase domain, while other two general drugs, i.e. DB02302 and DB08258, can also inhibit the synthase at nanomolar level. Structural bioinformatics analysis revealed diverse noncovalent interactions such as hydrogen bonds, hydrophobic forces and van der Waals contacts across the complex interface of nNOS active site with these identified drugs, conferring both stability and specificity for the complex recognition and association.

Protective effect of grape seed extract and orlistat co-treatment against stroke: Effect on oxidative stress and energy failure

Ischemic stroke is a major health concern and a leading cause of mortality worldwide. Oxidative stress is an early event in the course of stroke inducing neuro-inflammation and cell death. Grape seed extract (GSE) is a natural phytochemical mixture exhibiting antioxidant, anti-inflammatory and neuroprotective properties. Orlistat (ORL) is an anti-obesity agent and a gastro-intestinal lipase inhibitor which showed recently beneficial effects on brain lipotoxicity. Recent studies reported the increase of lipase activity upon stroke which led us to investigate the neuroprotective effect of ORL on rat brain I/R injury as well as the putative synergism with GSE. I/R insult infarcted the brain parenchyma as assessed by TTC staining, induced an oxidative stress as revealed by increased lipoperoxidation along with alteration of antioxidant enzymes activities which was corrected using the cotreatment of ORL + GSE. I/R also disturbed the main metabolic pathways involved in brain fueling as glycolysis, neoglucogenesis, glycogenolysis, TCA cycle and electron transfer chain (ETC) complexes. These disturbances were also corrected with the cotreatment ORL + GSE which maintained energetic activities near to the control level. I/R also disrupted transition metals distribution, along with associated enzymes as tyrosinase, LDH or glutamine synthetase activities and induced hippocampal inflammation as revealed by glycogen depletion from dentate gyrus area along with depressed anti-inflammatory IL1β cytokine and increased pro-inflammatory CD68 antigen. Interestingly almost all I/R-induced disturbances were corrected either partially upon ORL and GSE on their own and the best neuroprotection was obtained in the presence of both drugs (ORL + GSE) enabling robust neuroprotection of the sub granular zone within hippocampal dentate gyrus area.

Engineering bioscaffolds for enzyme assembly

With the demand for green, safe, and continuous biocatalysis, bioscaffolds, compared with synthetic scaffolds, have become a desirable candidate for constructing enzyme assemblages because of their biocompatibility and regenerability. Biocompatibility makes bioscaffolds more suitable for safe and green production, especially in food processing, production of bioactive agents, and diagnosis. The regenerability can enable the engineered biocatalysts regenerate through simple self-proliferation without complex re-modification, which is attractive for continuous biocatalytic processes. In view of the unique biocompatibility and regenerability of bioscaffolds, they can be classified into non-living (polysaccharide, nucleic acid, and protein) and living (virus, bacteria, fungi, spore, and biofilm) bioscaffolds, which can fully satisfy these two unique properties, respectively. Enzymes assembled onto non-living bioscaffolds are based on single or complex components, while enzymes assembled onto living bioscaffolds are based on living bodies. In terms of their unique biocompatibility and regenerability, this review mainly covers the current advances in the research and application of non-living and living bioscaffolds with focus on engineering strategies for enzyme assembly. Finally, the future development of bioscaffolds for enzyme assembly is also discussed. Hopefully, this review will attract the interest of researchers in various fields and empower the development of biocatalysis, biomedicine, environmental remediation, therapy, and diagnosis.

Protective effect of (Xenical+GSF) against I/R-induced blood brain barrier disruption, ionic edema, lipid deregulation and neuroinflammation

Ischemic stroke is a leading cause of mortality worldwide that occurs following the reduction or interruption of blood brain supply, characterized by a cascade of early events as oxidative stress and ensuing neuro-inflammation, energy failure and the burst of intracellular Ca++ resulting in activation of phospholipases and large increase in FFA including arachidonic acid, ultimately leading to nervous cell death. Grape Seed Flour (GSF) is a complex polyphenolic mixture harboring antioxidant, anti-inflammatory and neuroprotective properties. Orlistat (Xenical ™,Xe) is a gastro-intestinal lipase inhibitor and an anti-obesity agent. In an earlier study we reported the higher efficiency in neuroprotection against HFD-induced brain lipotoxicity when combining the two drugs (GSF + Xe). As a result repurposing Xe as an adjunct to GSF therapy against stroke appeared relevant and worthy of investigation. I/R insult disrupted the blood brain barrier (BBB) as assessed by EB dye extravasation, increased water and Na⁺ within the brain. Ultrastructurally I/R altered the brain blood capillaries at the vicinity of hippocampus dentate gyrus area as assessed by transmission and scanning electron microscopy. I/R altered lipid metabolism as revealed by LDL/HDL ratio, lipase activity, and FFA profiles. Moreover, I/R induced neuro-inflammation as assessed by down-regulation of anti-inflammatory CD 56 and up-regulation of pro-inflammatory CD 68 antigen. Importantly almost all I/R-induced disturbances were retrieved partially upon Xe or GSF on their own, and optimally when combining the two drugs. Xe per se is protective against I/R injury and the best neuroprotection was obtained when associating low dosage Xe with high dosage GSF, enabling neuroprevention and cell survival within hippocampus dentate gyrus area as revealed by increased staining of Ki 67 proliferation biomarker.

Simple and rapid real-time monitoring of LPL activity in vitro

Since elevated plasma triglycerides are an independent risk factor for cardiovascular diseases, lipoprotein lipase (LPL) is an interesting target for drug development. However, investigation of LPL remains challenging, as most of the commercially available assays are limited to the determination of LPL activity. Thus, we focused on the evaluation of a simple in vitro real-time fluorescence assay for the measurement of LPL activity that can be combined with additional cell or molecular biological assays in the same cell sample. Our procedure allows for a more comprehensive characterization of potential regulatory compounds targeting the LPL system.

The presented assay procedure provides several advantages over currently available commercial in vitro LPL activity assays:1.

12-well cell culture plate design for the simultaneous investigation of up to three different compounds of interest (including all assay controls).

2.

24 h real-time acquisition of LPL activity for the identification of the optimal time point for further measurements.

3.

Measurement of LPL activity can be supplemented by additional cell or molecular biological assays in the same cell sample.

Transnasal Delivery of the Peptide Agonist Specific to Neuromedin-U Receptor 2 to the Brain for the Treatment of Obesity

Obesity and metabolic syndrome are threats to the health of large population worldwide as they are associated with high mortality, mainly linked to cardiovascular diseases. Recently, CPN-116 (CPN), which is an agonist peptide specific to neuromedin-U receptor 2 (NMUR2) that is expressed predominantly in the brain, has been developed as a new therapeutic candidate for the treatment of obesity and metabolic syndrome. However, treatment with CPN poses a challenge due to the limited delivery of CPN to the brain. Recent studies have clarified that the direct anatomical connection of the nasal cavity with brain allows delivery of several drugs to the brain. In this study, we confirm the nasal cavity as a promising CPN delivery route to the brain for the treatment of obesity and metabolic syndrome. According to the pharmacokinetic study, the clearance of CPN from the blood was very rapid with a half-life of 3 min. In vitro study on its stability in the serum and cerebrospinal fluid (CSF) indicates that CPN was more stable in the CSF than in the blood. The concentration of CPN in the brain was higher after nasal administration, despite its lower concentrations in the plasma than that after intravenous administration. The study on its pharmacological potency suggests the effective suppression of increased body weight in mice in a dose-dependent manner due to the direct activation of NMUR2 by CPN. This results from the higher concentration of corticosterone in blood after nasal administration of CPN as compared to nasal application of saline. In conclusion, the above findings indicate that the nasal cavity is a promising CPN delivery route to the brain to treat obesity and metabolic syndrome.

Orlistat increases arsenite tolerance in THP-1 derived macrophages through the up-regulation of ABCA1

Orlistat is an FDA-approved over-the-counter drug to treat obesity through the inhibition of lipase activity. Macrophages, which express high levels of lipoprotein lipase (LPL), are important phagocytes in the innate immune system. Our previous studies indicated that environmentally relevant concentrations of arsenite (As⁺³) could inhibit the major immune functions of macrophages. As the down-regulation of LPL is known to increase the expression of ABCA1, the cholesterol exporter demonstrated to be related to the resistance of arsenic toxicity. We examined if orlistat could reverse the inhibitive effects of As⁺³ on macrophage functions. The results showed that 50 μM orlistat reversed As⁺³-induced suppressions on phagocytosis, NO production and cytokine secretion in THP-1 derived macrophages. The expression of ABCA1 was significantly increased by orlistat in As⁺³ co-treated macrophages, which was associated with decreased intracellular As⁺³ levels. Collectively, these results indicated that orlistat could reverse the suppressive effects induced by As⁺³ in macrophages through the increased expression of ABCA1, which has the potential to be developed as a therapeutic agent for arsenic-induced immunosuppression.

Progress in Spore Surface Display Technology towards Environment, Vaccine Development, and Biocatalysis

Spore surface display is the most desirable with enhanced effects, low cost, less time consuming and the most promising technology for environmental, medical, and industrial development. Spores have various applications in industry due to their ability to survive in harsh industrial processes including heat resistance, alkaline tolerance, chemical tolerance, easy recovery, and reusability. Yeast and bacteria, including gram-positive and -negative, are the most frequently used organisms for the display of various proteins (eukaryotic and prokaryotic), but unlike spores, they can rupture easily due to nutritive properties, susceptibility to heat, pH, and chemicals. Hence, spores are the best choice to avoid these problems, and they have various applications over nonspore formers due to amenability for laboratory purposes. Various strains of <i>Clostridium</i> and <i>Bacillus</i> are spore formers, but the most suitable choice for display is <i>Bacillus subtilis</i> because, according to the WHO, it is safe to humans and considered as “GRAS” (generally recognized as safe). This review focuses on the application of spore surface display towards industries, vaccine development, the environment, and peptide library construction, with cell surface display for enhanced protein expression and high enzymatic activity. Different vectors, coat proteins, and statistical analyses can be used for linker selection to obtain greater expression and high activity of the displayed protein.