Identification of potential drug targets in human pathogen Bacillus cereus and insight for finding inhibitor through subtractive proteome and molecular docking studies.
- 作者列表："Anis Ahamed N","Panneerselvam A","Arif IA","Syed Abuthakir MH","Jeyam M","Ambikapathy V","Mostafa AA
:Bacillus cereus is a gram-positive, anaerobic, spore-forming bacterium related to food poisoning in humans. Vomit and diarrhea are the symptoms of foodborne B. cereus infection caused by emetic toxins and three enterotoxins, respectively. This bacterium is broadly present in soil and foods such as vegetables, spices, milk, and meat. The antibiotics impenem, vancomycin, chloramphenicol, gentamicin, and ciprofloxacin are used for all susceptible strains of B. cereus. But these antibiotics cause side effects in the host due to the drug-host interaction; because the targeted proteins by the drugs are not pathogen specific proteins, they are similar to human proteins also. To overcome this problem, this study focused on identifying putative drug targets in the pathogen B. cereus and finding new drugs to inhibit the function of the pathogen. The identification of drug targets is a pipeline process, starting with the identification of targets non-homologous to human and gutmicrobiota proteins, finding essential proteins, finding other proteins that highly interact with these essential proteins that are also highly important for protein network stability, finding cytoplasmic proteins with a clear pathway and known molecular function, and finding non-druggable proteins. Through this process, two novel drug targets were identified in B. cereus. Among the various antibiotics, Gentamicin had showed good binding affinity with the identified novel targets through molecular modeling and docking studies using Prime and GLIDE module of Schrödinger. Hence, this study suggest that the identified novel drug targets may very useful in drug therapeutic field for finding inhibitors which are similar to Gentamicin and designing new formulation of drug molecules to control the function of the foodborne illness causing pathogen B. cereus.
: 蜡样芽孢杆菌是一种革兰氏阳性、厌氧、产芽孢的细菌，与人类食物中毒有关。呕吐和腹泻分别是由呕吐毒素和三种肠毒素引起的食源性蜡样芽孢杆菌感染的症状。这种细菌广泛存在于土壤和食物中，如蔬菜，香料，牛奶和肉类。抗生素impenem、万古霉素、氯霉素、庆大霉素和环丙沙星用于所有敏感的蜡样芽孢杆菌菌株。但这些抗生素由于药物-宿主相互作用而在宿主中引起副作用; 由于药物的靶向蛋白质不是病原体特异性蛋白质，它们也与人类蛋白质相似。为了克服这个问题，本研究集中在鉴定病原体蜡状芽孢杆菌中的推定药物靶标和寻找抑制病原体功能的新药。药物靶点的鉴定是一个流水线过程，从鉴定与人类和内脏微生物群蛋白非同源的靶点开始，寻找必需蛋白，寻找与这些必需蛋白高度相互作用的其他蛋白，这些蛋白对蛋白网络稳定性也非常重要，寻找具有明确途径和已知分子功能的细胞质蛋白，找到不可用药的蛋白质。通过该过程，在蜡状芽孢杆菌中鉴定了两个新的药物靶标。在各种抗生素中，通过使用薛定谔的Prime和GLIDE模块的分子建模和对接研究，庆大霉素与鉴定的新靶标表现出良好的结合亲和力。因此，本研究表明，所鉴定的新药物靶标可能在药物治疗领域非常有用，用于寻找与庆大霉素相似的抑制剂，并设计药物分子的新制剂以控制引起食源性疾病的病原体蜡状芽孢杆菌的功能。
METHODS::The ATP binding-cassette superfamily corresponds the mostly transmembrane transporters family found in humans. These proteins actively transport endogenous and exogenous substrates through biological membranes in body tissues, so they have an important role in the regulation of many physiological functions necessary for human homeostasis, as well as in response regulation to several pharmacological substrates. The development of multidrug resistance has become one of the main troubles in conventional chemotherapy in different illnesses including cancer, being the increased efflux of antineoplastic drugs the main reason for this multidrug resistance, with a key role of the ABC superfamily. Likely, the interindividual variability in the pharmacological response among patients is well known, and may be due to intrinsically factors of the disease, genetic and environmental ones. Thus, the understanding of this variability, especially the genetic variability associated with the efficacy and toxicity of drugs, can provide a safer and more effective pharmacological treatment, so ABC genes are considered as important regulators due to their relationship with the reduction in pharmacological response. In this review, updated information about transporters belonging to this superfamily was collected, the possible role of these transporters in cancer, the role of genetic variability in their genes, as well as some therapeutic tools that have been tried to raise against main transporters associated with chemoresistance in cancer.
METHODS:BACKGROUND:Cholinergic neurotransmission regulates neuroinflammation in Parkinson disease (PD). RESEARCH DESIGN AND METHODS:The authors conducted a delayed-start study of donepezil for cognitive decline in non-demented PD patients. The study consisted of a 96-week randomized placebo-controlled double-blind phase 1, followed by a 24-week donepezil extension phase 2. The primary outcome measure was a change in the Mini-Mental State Examination (MMSE) at week 120. RESULTS:A total of 98 patients were randomly allocated to the early-start (donepezil-to-donepezil) and delayed-start (placebo-to-donepezil) groups. Mean (SD) of the baseline MMSE was 27.6 (2.0) and 28.0 (2.1), respectively. MMSE change at week 120 was better in the early-start group than in the delayed-start group, but the difference was not significant. The MMSE declined in apolipoprotein ε4 carriers, but not in non-carriers, and the factor interaction (intervention × ε4 genotype) was highly significant (P < 0.001). Analyzed with the interaction, the difference was significant (group difference 1.95 [0.33 to 3.57], P = 0.018). The MMSE decline slope in phase 1 was significantly better in the early-start group than in the delayed-start group (P = 0.048). CONCLUSIONS:Cognitive function deteriorated in ε4 carriers, but not in non-carriers, and early-start donepezil may postpone cognitive decline in the former.
METHODS::Since the discovery of dental pulp stem cells, a lot of teams have expressed an interest in dental pulp regeneration. Many approaches, experimental models and biological explorations have been developed, each including the use of stem cells and scaffolds with the final goal being clinical application in humans. In this review, the authors' objective was to compare the experimental models and strategies used for the development of biomaterials for tissue engineering of dental pulp with stem cells. Electronic queries were conducted on PubMed using the following terms: pulp regeneration, scaffold, stem cells, tissue engineering and biomaterial. The extracted data included the following information: the strategy envisaged, the type of stem cells, the experimental models, the exploration or analysis methods, the cytotoxicity or viability or proliferation cellular tests, the tests of scaffold antibacterial properties and take into account the vascularization of the regenerated dental pulp. From the 71 selected articles, 59% focused on the "cell-transplantation" strategy, 82% used in vitro experimentation, 58% in vivo animal models and only one described an in vivo in situ human clinical study. 87% used dental pulp stem cells. A majority of the studies reported histology (75%) and immunohistochemistry explorations (66%). 73% mentioned the use of cytotoxicity, proliferation or viability tests. 48% took vascularization into account but only 6% studied the antibacterial properties of the scaffolds. This article gives an overview of the methods used to regenerate dental pulp from stem cells and should help researchers create the best development strategies for research in this field.