scholarly journals Challenges in Drug Discovery for Intracellular Bacteria

Pathogens ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1172
Author(s):  
Allison N. Tucker ◽  
Travis J. Carlson ◽  
Aurijit Sarkar
Keyword(s):  
Drug Discovery ◽  
Virulence Factors ◽  
Mammalian Cells ◽  
Drug Targets ◽  
Bacterial Pathogens ◽  
Intracellular Bacteria ◽  
Current State ◽  
Novel Drugs ◽  
Bacterial Cytoplasm ◽  
Available Information

Novel drugs are needed to treat a variety of persistent diseases caused by intracellular bacterial pathogens. Virulence pathways enable many functions required for the survival of these pathogens, including invasion, nutrient acquisition, and immune evasion. Inhibition of virulence pathways is an established route for drug discovery; however, many challenges remain. Here, we propose the biggest problems that must be solved to advance the field meaningfully. While it is established that we do not yet understand the nature of chemicals capable of permeating into the bacterial cell, this problem is compounded when targeting intracellular bacteria because we are limited to only those chemicals that can permeate through both human and bacterial outer envelopes. Unfortunately, many chemicals that permeate through the outer layers of mammalian cells fail to penetrate the bacterial cytoplasm. Another challenge is the lack of publicly available information on virulence factors. It is virtually impossible to know which virulence factors are clinically relevant and have broad cross-species and cross-strain distribution. In other words, we have yet to identify the best drug targets. Yes, standard genomics databases have much of the information necessary for short-term studies, but the connections with patient outcomes are yet to be established. Without comprehensive data on matters such as these, it is difficult to devise broad-spectrum, effective anti-virulence agents. Furthermore, anti-virulence drug discovery is hindered by the current state of technologies available for experimental investigation. Antimicrobial drug discovery was greatly advanced by the establishment and standardization of broth microdilution assays to measure the effectiveness of antimicrobials. However, the currently available models used for anti-virulence drug discovery are too broad, as they must address varied phenotypes, and too expensive to be generally adopted by many research groups. Therefore, we believe drug discovery against intracellular bacterial pathogens can be advanced significantly by overcoming the above hurdles.

scholarly journals Opportunities and Challenges of Bacterial Glycosylation for the Development of Novel Antibacterial Strategies

2021 ◽  
Vol 12 ◽  
Author(s):  
Liubov Yakovlieva ◽  
Julius A. Fülleborn ◽  
Marthe T. C. Walvoort
Keyword(s):  
Virulence Factors ◽  
Drug Targets ◽  
Bacterial Population ◽  
Molecular Mimicry ◽  
Bacterial Pathogens ◽  
Current Status ◽  
Novel Drug ◽  
Bacterial Glycosylation ◽  
Novel Drug Targets ◽  
Selection Of

Glycosylation is a ubiquitous process that is universally conserved in nature. The various products of glycosylation, such as polysaccharides, glycoproteins, and glycolipids, perform a myriad of intra- and extracellular functions. The multitude of roles performed by these molecules is reflected in the significant diversity of glycan structures and linkages found in eukaryotes and prokaryotes. Importantly, glycosylation is highly relevant for the virulence of many bacterial pathogens. Various surface-associated glycoconjugates have been identified in bacteria that promote infectious behavior and survival in the host through motility, adhesion, molecular mimicry, and immune system manipulation. Interestingly, bacterial glycosylation systems that produce these virulence factors frequently feature rare monosaccharides and unusual glycosylation mechanisms. Owing to their marked difference from human glycosylation, bacterial glycosylation systems constitute promising antibacterial targets. With the rise of antibiotic resistance and depletion of the antibiotic pipeline, novel drug targets are urgently needed. Bacteria-specific glycosylation systems are especially promising for antivirulence therapies that do not eliminate a bacterial population, but rather alleviate its pathogenesis. In this review, we describe a selection of unique glycosylation systems in bacterial pathogens and their role in bacterial homeostasis and infection, with a focus on virulence factors. In addition, recent advances to inhibit the enzymes involved in these glycosylation systems and target the bacterial glycan structures directly will be highlighted. Together, this review provides an overview of the current status and promise for the future of using bacterial glycosylation to develop novel antibacterial strategies.

Drug Discovery and Target Identification against Schistosomiasis: a Reality Check on Progress and Future Prospects

2021 ◽  
Vol 21 ◽  
Author(s):  
Peter Mubanga Cheuka
Keyword(s):  
Drug Discovery ◽  
Drug Targets ◽  
Target Identification ◽  
Repeated Administration ◽  
Clinical Use ◽  
Future Prospects ◽  
Reality Check ◽  
Novel Drugs ◽  
Preclinical Species ◽  
Chemotherapeutic Treatment

: Schistosomiasis ranks among the most important infectious diseases, with over 200 million people currently being infected and > 280,000 deaths reported annually. Chemotherapeutic treatment has relied on one drug, praziquantel, for four decades, while other drugs, such as oxamniquine and metrifonate, are no longer preferred for clinical use due to their narrow spectrum of activity - these are only active against S. mansoni and S. haematobium, respectively. Despite being cheap, safe, and effective against all schistosome species, praziquantel is ineffective against immature worms, which may lead to reinfections and treatment failure in endemic areas; a situation that necessitates repeated administration besides other limitations. Therefore, novel drugs are urgently needed to overcome this situation. In this paper, an up to date review of drug targets identified and validated against schistosomiasis while also encompassing promising clinical and preclinical candidate drugs is presented. While there are considerable efforts aimed at identifying and validating drug targets, the pipeline for new antischistosomals is dry. Moreover, the majority of compounds evaluated preclinically are not really advanced because most of them were evaluated in very small preclinical species such as mice alone. Overall, it appears that although a lot of research is going on at discovery phases, unfortunately, it does not translate to advanced preclinical and clinical evaluation.

Ultrastructural Alterations in Hela Cells Induced by Spider Venom

1967 ◽  
Vol 25 ◽  
pp. 20-21
Author(s):  
Dale E. McClendon ◽  
Paul N. Morgan ◽  
Bernard L. Soloff
Keyword(s):  
Growth Medium ◽  
Mammalian Cells ◽  
Carcinoma Cells ◽  
Venom Protein ◽  
Sterile Saline ◽  
Carbon Coated ◽  
Available Information ◽  
Loxosceles Reclusa ◽  
Essential Growth ◽  
Solution Cultures

It has been observed that minute amounts of venom from the brown recluse spider, Loxosceles reclusa, are capable of producing cytotoxic changes in cultures of certain mammalian cells (Morgan and Felton, 1965). Since there is little available information concerning the effect of venoms on susceptible cells, we have attempted to characterize, at the electron microscope level, the cytotoxic changes produced by the venom of this spider.Cultures of human epithelial carcinoma cells, strain HeLa, were initiated on sterile, carbon coated coverslips contained in Leighton tubes. Each culture was seeded with approximately 1x105 cells contained in 1.5 ml of a modified Eagle's minimum essential growth medium prepared in Hank's balanced salt solution. Cultures were incubated at 36° C. for three days prior to the addition of venom. The venom was collected from female brown recluse spiders and diluted in sterile saline. Protein determinations on the venom-were made according to the spectrophotometric method of Waddell (1956). Approximately 10 μg venom protein per ml of fresh medium was added to each culture after discarding the old growth medium. Control cultures were treated similarly, except that no venom was added. All cultures were reincubated at 36° C.

Phytochemicals for drug discovery in Alzheimer’s disease: In silico Advances

2020 ◽  
Vol 26 ◽  
Author(s):  
Smriti Sharma ◽  
Vinayak Bhatia
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Drug Design ◽  
In Silico ◽  
Drug Targets ◽  
Development Process ◽  
Phytochemical Analysis ◽  
Computational Drug Design ◽  
Novel Drugs ◽  
Game Changer

: The search for novel drugs that can prevent or control Alzheimer’s disease has attracted lot of attention from researchers across the globe. Phytochemicals are increasingly being used to provide scaffolds to design drugs for AD. In silico techniques, have proven to be a game-changer in this drug design and development process. In this review, the authors have focussed on current advances in the field of in silico medicine, applied to phytochemicals, to discover novel drugs to prevent or cure AD. After giving a brief context of the etiology and available drug targets for AD, authors have discussed the latest advances and techniques in computational drug design of AD from phytochemicals. Some of the prototypical studies in this area are discussed in detail. In silico phytochemical analysis is a tool of choice for researchers all across the globe and helps integrate chemical biology with drug design.

Novel Therapeutic Approaches and Targets for Treatment of Chronic Urticaria: New Insights and Promising Targets for a Challenging Disease

2020 ◽  
Vol 22 (1) ◽  
pp. 32-45
Author(s):  
Emanuela Martina ◽  
Federico Diotallevi ◽  
Tommaso Bianchelli ◽  
Matteo Paolinelli ◽  
Annamaria Offidani
Keyword(s):  
English Language ◽  
Life Experience ◽  
Case Reports ◽  
Immunosuppressive Agents ◽  
Real Life ◽  
Chronic Spontaneous Urticaria ◽  
New Targets ◽  
Current State ◽  
Pubmed Database ◽  
Novel Drugs

Background: Chronic Spontaneous Urticaria (CSU) is a disease characterized by the onset of wheals and/or angioedema over 6 weeks. The pathophysiology for CSU is very complex, involving mast cells and basophils with a multitude of inflammatory mediators. For many years the treatment of CSU has been based on the use of antihistamines, steroids and immunosuppressive agents with inconstant and frustrating results. The introduction of omalizumab, the only licensed biologic for antihistamine- refractory CSU, has changed the management of the disease. Objective: The aim of this article is to review the current state of the art of CSU, the real-life experience with omalizumab and the promising drugs that are under development. Methods:: An electronic search was performed to identify studies, case reports, guidelines and reviews focused on the new targets for the treatment of chronic spontaneous urticaria, both approved or under investigation. The search was limited to articles published in peer-reviewed journals in the English Language in the PubMed database and trials registered in Clinicaltrials.gov. Results:: Since the advent of omalizumab, the search for new therapies for chronic spontaneous urticaria has had a new impulse. Anti-IgE drugs will probably still be the cornerstone of therapy, but new targets may prove effective in syndromic urticaria or refractory cases. Conclusion:: Although omalizumab has been a breakthrough in the treatment of CSU, many patients do not completely get benefit and even require more effective treatments. Novel drugs are under investigation with promising results.

Role of Cytochrome P450 in Prostate Cancer and its Therapy

2020 ◽  
Vol 16 (1) ◽  
pp. 63-73 ◽  
Author(s):  
Rishabh Kaushik ◽  
Sheeza Khan ◽  
Meesha Sharma ◽  
Srinivasan Hemalatha ◽  
Zeba Mueed ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cytochrome P450 ◽  
Drug Discovery ◽  
Cholesterol Metabolism ◽  
Molecular Targets ◽  
Health Concern ◽  
Metabolic Functions ◽  
Novel Drugs ◽  
Genes Encoding ◽  
Causes Of Mortality

Prostate cancer has become a global health concern as it is one of the leading causes of mortality in males. With the emerging drug resistance to conventional therapies, it is imperative to unravel new molecular targets for disease prevention. Cytochrome P450 (P450s or CYPs) represents a unique class of mixed-function oxidases which catalyses a wide array of biosynthetic and metabolic functions including steroidogenesis and cholesterol metabolism. Several studies have reported the overexpression of the genes encoding CYPs in prostate cancer cells and how they can be used as molecular targets for drug discovery. But due to functional redundancy and overlapping expression of CYPs in several other metabolic pathways there are several impediments in the clinical efficacy of the novel drugs reported till now. Here we review the most crucial P450 enzymes which are involved in prostate cancer and how they can be used as molecular targets for drug discovery along with the clinical limitations of the currently existing CYP inhibitors.

scholarly journals Baicalin Represses Type Three Secretion System of Pseudomonas aeruginosa through PQS System

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1497
Author(s):  
Pansong Zhang ◽  
Qiao Guo ◽  
Zhihua Wei ◽  
Qin Yang ◽  
Zisheng Guo ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Virulence Factors ◽  
Mammalian Cells ◽  
Secretion System ◽  
Chinese Herbs ◽  
Infection Model ◽  
Lung Pathology ◽  
Promising Alternative ◽  
The Impact

Therapeutics that target the virulence of pathogens rather than their viability offer a promising alternative for treating infectious diseases and circumventing antibiotic resistance. In this study, we searched for anti-virulence compounds against Pseudomonas aeruginosa from Chinese herbs and investigated baicalin from Scutellariae radix as such an active anti-virulence compound. The effect of baicalin on a range of important virulence factors in P. aeruginosa was assessed using luxCDABE-based reporters and by phenotypical assays. The molecular mechanism of the virulence inhibition by baicalin was investigated using genetic approaches. The impact of baicalin on P. aeruginosa pathogenicity was evaluated by both in vitro assays and in vivo animal models. The results show that baicalin diminished a plenty of important virulence factors in P. aeruginosa, including the Type III secretion system (T3SS). Baicalin treatment reduced the cellular toxicity of P. aeruginosa on the mammalian cells and attenuated in vivo pathogenicity in a Drosophila melanogaster infection model. In a rat pulmonary infection model, baicalin significantly reduced the severity of lung pathology and accelerated lung bacterial clearance. The PqsR of the Pseudomonas quinolone signal (PQS) system was found to be required for baicalin’s impact on T3SS. These findings indicate that baicalin is a promising therapeutic candidate for treating P. aeruginosa infections.

scholarly journals Helicobacter pylori Virulence Factors—Mechanisms of Bacterial Pathogenicity in the Gastric Microenvironment

Cells ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 27
Author(s):  
Jacek Baj ◽  
Alicja Forma ◽  
Monika Sitarz ◽  
Piero Portincasa ◽  
Gabriella Garruti ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Helicobacter Pylori ◽  
Gastric Mucosa ◽  
Virulence Factors ◽  
Premalignant Lesions ◽  
Bacterial Pathogenicity ◽  
Current State ◽  
Genetic And Environmental Factors ◽  
H Pylori ◽  
Stimulation Of

Gastric cancer constitutes one of the most prevalent malignancies in both sexes; it is currently the fourth major cause of cancer-related deaths worldwide. The pathogenesis of gastric cancer is associated with the interaction between genetic and environmental factors, among which infection by Helicobacter pylori (H. pylori) is of major importance. The invasion, survival, colonization, and stimulation of further inflammation within the gastric mucosa are possible due to several evasive mechanisms induced by the virulence factors that are expressed by the bacterium. The knowledge concerning the mechanisms of H. pylori pathogenicity is crucial to ameliorate eradication strategies preventing the possible induction of carcinogenesis. This review highlights the current state of knowledge and the most recent findings regarding H. pylori virulence factors and their relationship with gastric premalignant lesions and further carcinogenesis.

scholarly journals Genomics-driven drug discovery based on disease-susceptibility genes

2021 ◽  
Vol 41 (1) ◽  
Author(s):  
Kyuto Sonehara ◽  
Yukinori Okada
Keyword(s):  
Drug Discovery ◽  
Drug Targets ◽  
Disease Susceptibility ◽  
Mendelian Randomization ◽  
Association Studies ◽  
Drug Repurposing ◽  
Susceptibility Genes ◽  
Genome Wide Association Studies ◽  
Genome Wide ◽  
Disease Associations

AbstractGenome-wide association studies have identified numerous disease-susceptibility genes. As knowledge of gene–disease associations accumulates, it is becoming increasingly important to translate this knowledge into clinical practice. This challenge involves finding effective drug targets and estimating their potential side effects, which often results in failure of promising clinical trials. Here, we review recent advances and future perspectives in genetics-led drug discovery, with a focus on drug repurposing, Mendelian randomization, and the use of multifaceted omics data.

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