scholarly journals High Throughput Phenotypic Screening of The Human Spermatozoon

Reproduction ◽  
2021 ◽  
Author(s):  
Zoe Claire Johnston ◽  
Franz S Gruber ◽  
Sean Brown ◽  
Neil R Norcross ◽  
Jason R Swedlow ◽  
...  

Despite recent advances in male reproductive health research, there remain many elements of male (in)fertility where our understanding is incomplete. Consequently, diagnostic tools and treatments for men with sperm dysfunction, other than medically assisted reproduction, are limited. On the other hand, the gaps in our knowledge of the mechanisms which underpin sperm function have hampered the development of male non-hormonal contraceptives. The study of mature spermatozoa is inherently difficult. They are a unique and highly specialised cell type which does not actively transcribe or translate proteins and cannot be cultured for long periods of time or matured in vitro. One, large scale, approach to both increasing understanding of sperm function, and the discovery and development of compounds that can modulate sperm function, is to directly observe responses to compounds with phenotypic screening techniques. These target agnostic approaches can be developed into high-throughput screening platforms with the potential to drastically increase advances in the field. Here we discuss the rationale and development of high-throughput phenotypic screening platforms for mature human spermatozoa, and the multiple potential applications these present, as well as the current limitations and leaps in our understanding and capabilities needed to overcome them. Further development and use of these technologies could lead to the identification of compounds which positively or negatively affect sperm cell motility or function, or novel platforms for toxicology or environmental chemical testing among other applications. Ultimately, each of these potential applications is also likely to increase understanding within the field of sperm biology.

2021 ◽  
Author(s):  
Franz S. Gruber ◽  
Zoe C. Johnston ◽  
Neil R. Norcross ◽  
Irene Georgiou ◽  
Caroline Wilson ◽  
...  

AbstractStudy questionCan a high-throughput screening platform facilitate male fertility drug discovery?Summary answerA high-throughput screening platform identified a large number of compounds that enhanced sperm motility.What is known alreadySeveral efforts to find small molecules modulating sperm function have been performed but not using high-throughput technology.Study design, size, durationHealthy donor semen samples were used and samples were pooled (3-5 donors per pool). Primary screening was performed in singlicate; dose-response screening was performed in duplicate (independent donor pools).Participants/materials, setting, methodsSpermatozoa isolated from healthy donors were prepared by density gradient centrifugation and incubated in 384-well plates with compounds (6.25 uM) to identify those compounds with enhancing effects on motility. A total of ∼17,000 compounds from the following libraries: ReFRAME, Prestwick, Tocris, LOPAC, CLOUD and MMV Pathogen Box were screened. Dose response experiments of screening hits were performed to confirm the enhancing effect on sperm motility. Experiments were performed in a University setting.Main results and the role of chanceFrom our primary single concentration screening, 105 compounds elicited an enhancing effect on sperm motility compared to DMSO treated wells. Confirmed enhancing compounds were grouped based on their annotated targets/target classes. A major target class, phosphodiesterase inhibitors, were identified in particular PDE10A inhibitors as well as number of compounds not previously identified/known to enhance human sperm motility such as those related to GABA signaling.Limitations, reasons for cautionCompounds have been tested with prepared donor spermatozoa and only incubated for a short period of time. Therefore, the effect of compounds on whole semen or with longer incubation time may be different. All experiments were performed in vitro.Wider implications of the findingsThis phenotypic screening assay identified a large number of compounds that increased sperm motility. In addition to furthering our understanding of human sperm function, for example identifying new avenues for discovery, we highlight potential inhibitors as promising start-point for a medicinal chemistry programme for potential enhancement of male infertility. Moreover, with disclosure of the results of screening we present a substantial resource to inform further work in the fieldStudy funding/competing interest(s)This study was supported by the Bill and Melinda Gates Foundation and Scottish Funding Council and Scottish Universities Life Science Alliance.


2020 ◽  
Vol 12 (8) ◽  
pp. 630-643 ◽  
Author(s):  
Yuhong Du ◽  
Xingnan Li ◽  
Qiankun Niu ◽  
Xiulei Mo ◽  
Min Qui ◽  
...  

Abstract The recent advent of robust methods to grow human tissues as 3D organoids allows us to recapitulate the 3D architecture of tumors in an in vitro setting and offers a new orthogonal approach for drug discovery. However, organoid culturing with extracellular matrix to support 3D architecture has been challenging for high-throughput screening (HTS)-based drug discovery due to technical difficulties. Using genetically engineered human colon organoids as a model system, here we report our effort to miniaturize such 3D organoid culture with extracellular matrix support in high-density plates to enable HTS. We first established organoid culturing in a 384-well plate format and validated its application in a cell viability HTS assay by screening a 2036-compound library. We further miniaturized the 3D organoid culturing in a 1536-well ultra-HTS format and demonstrated its robust performance for large-scale primary compound screening. Our miniaturized organoid culturing method may be adapted to other types of organoids. By leveraging the power of 3D organoid culture in a high-density plate format, we provide a physiologically relevant screening platform to model tumors to accelerate organoid-based research and drug discovery.


2020 ◽  
Vol 26 (1) ◽  
pp. 113-121
Author(s):  
Yuka Otsuka ◽  
Michael V. Airola ◽  
Yong-Mi Choi ◽  
Nicolas Coant ◽  
Justin Snider ◽  
...  

There is interest in developing inhibitors of human neutral ceramidase (nCDase) because this enzyme plays a critical role in colon cancer. There are currently no potent or clinically effective inhibitors for nCDase reported to date, so we adapted a fluorescence-based enzyme activity method to a high-throughput screening format. We opted to use an assay whereby nCDase hydrolyzes the substrate RBM 14-16, and the addition of NaIO4 acts as an oxidant that releases umbelliferone, resulting in a fluorescent signal. As designed, test compounds that act as ceramidase inhibitors will prevent the hydrolysis of RBM 14-16, thereby decreasing fluorescence. This assay uses a 1536-well plate format with excitation in the blue spectrum of light energy, which could be a liability, so we incorporated a counterscreen that allows for rapid selection against fluorescence artifacts to minimize false-positive hits. The high-throughput screen of >650,000 small molecules found several lead series of hits. Multiple rounds of chemical optimization ensued with improved potency in terms of IC50 and selectivity over counterscreen assays. This study describes the first large-scale high-throughput optical screening assay for nCDase inhibitors that has resulted in leads that are now being pursued in crystal docking studies and in vitro drug metabolism and pharmacokinetics (DMPK).


Author(s):  
Shang-Chih Lai ◽  
Ren-In You ◽  
Tz-Ting Chen ◽  
Yu Chang ◽  
Chao-Zong Liu ◽  
...  

Background: Frankincense is a resin secreted by the Boswellia tree. It is used in perfumery, aromatherapy, skincare, and traditional Chinese medicine. However, all Boswellia species are under threat owing to habitat loss and overexploitation. As a result, the market is getting flooded with counterfeit frankincense products. Objective: This study aims to establish a high-throughput method to screen and identify the authenticity of commercial frankincense products. We report, for the first time, a matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS)-based method for rapid and high-throughput screening of frankincense samples. Methods: MALDI-TOF MS, HPLC, thin-layer chromatography (TLC), and in vitro anti-inflammatory activity assay were used to examine the frankincense samples. Results: Well-resolved peaks of frankincense triterpenoids in the spectra were observed in the crude extract of commercial samples, including α-boswellic acids (αBAs), β-boswellic acids (βBAs), 11-keto-β-boswellic acids (KBAs), acetyl-11-keto-β-boswellic acids (AKBAs), and their esters. These compounds can be used as indicators for determining the authenticity of frankincense. Conclusion: Unlike LC–MS, which is a time-consuming and expensive method, and TLC, which requires a reference sample, our inexpensive, rapid high-throughput identification method based on MALDI-TOF MS is ideal for large-scale screening of frankincense samples sold in the market.


2021 ◽  
Author(s):  
Conall Sauvey ◽  
Gretchen Ehrenkaufer ◽  
Jonathan Blevitt ◽  
Paul Jackson ◽  
Ruben Abagyan

AbstractEntamoeba histolytica is a disease-causing parasitic amoeba which affects an estimated 50 million people worldwide, particularly in socioeconomically vulnerable populations experiencing water sanitation issues. Infection with E. histolytica is referred to as amoebiasis, and can cause symptoms such as colitis, dysentery, and even death in extreme cases. Drugs exist that are capable of killing this parasite, but they are hampered by downsides such as significant adverse effects at therapeutic concentrations, issues with patient compliance, the need for additional drugs to kill the transmissible cyst stage, and potential development of resistance. Past screens of small and medium sized chemical libraries have yielded anti-amoebic candidates, thus rendering high-throughput screening a promising direction for new drug discovery in this area. In this study, we screened a curated 80,000-compound library from Janssen pharmaceuticals against E. histolytica trophozoites in vitro, and from it identified a highly potent new inhibitor compound. Further experimentation confirmed the activity of this compound, as well as that of several structurally related compounds, originating from both the Janssen Jump-stARter library, and from chemical vendors, thus highlighting a new structure-activity relationship (SAR). In addition, we confirmed that the compound inhibited E. histolytica survival as rapidly as the current standard of care and inhibited transmissible cysts of the related model organism Entamoeba invadens. Together these results constitute the discovery of a novel class of chemicals with favorable in vitro pharmacological properties which may lead to an improved therapy against this parasite and in all of its life stages.Author summaryThe parasite Entamoeba histolytica represents a significant challenge in the field of global health. It currently infects and causes disease among millions of people worldwide, particularly those lacking access to clean water. Drugs exist to treat this disease, but nevertheless it persists as a problem, likely at least partly due to problems and downsides inherent to these drugs. Hence the search for new and better ones is needed. We report here our contribution to this search, consisting of testing a large, carefully-curated collection of tens of thousands of chemicals for their ability to kill E. histolytica. This large-scale test resulted in the identification of one of the compounds as potently anti-amoebic, capable of killing the parasite cells at extremely low concentrations. Further experimentation found several chemically-related compounds to also possess this property, and additionally found the first compound capable of killing the infective life stage of another Entamoeba parasite. These results have revealed an entire new family of chemicals with good potential for development as better drugs against this disease.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Zi-Xu Liu ◽  
Si-Ling Huang ◽  
Jin Hou ◽  
Xue-Ping Guo ◽  
Feng-Shan Wang ◽  
...  

AbstractValuable polysaccharides are usually produced using wild-type or metabolically-engineered host microbial strains through fermentation. These hosts act as cell factories that convert carbohydrates, such as monosaccharides or starch, into bioactive polysaccharides. It is desirable to develop effective in vivo high-throughput approaches to screen cells that display high-level synthesis of the desired polysaccharides. Uses of single or dual fluorophore labeling, fluorescence quenching, or biosensors are effective strategies for cell sorting of a library that can be applied during the domestication of industrial engineered strains and metabolic pathway optimization of polysaccharide synthesis in engineered cells. Meanwhile, high-throughput screening strategies using each individual whole cell as a sorting section are playing growing roles in the discovery and directed evolution of enzymes involved in polysaccharide biosynthesis, such as glycosyltransferases. These enzymes and their mutants are in high demand as tool catalysts for synthesis of saccharides in vitro and in vivo. This review provides an introduction to the methodologies of using cell-based high-throughput screening for desired polysaccharide-biosynthesizing cells, followed by a brief discussion of potential applications of these approaches in glycoengineering.


2019 ◽  
Author(s):  
Mohammad Atif Faiz Afzal ◽  
Mojtaba Haghighatlari ◽  
Sai Prasad Ganesh ◽  
Chong Cheng ◽  
Johannes Hachmann

<div>We present a high-throughput computational study to identify novel polyimides (PIs) with exceptional refractive index (RI) values for use as optic or optoelectronic materials. Our study utilizes an RI prediction protocol based on a combination of first-principles and data modeling developed in previous work, which we employ on a large-scale PI candidate library generated with the ChemLG code. We deploy the virtual screening software ChemHTPS to automate the assessment of this extensive pool of PI structures in order to determine the performance potential of each candidate. This rapid and efficient approach yields a number of highly promising leads compounds. Using the data mining and machine learning program package ChemML, we analyze the top candidates with respect to prevalent structural features and feature combinations that distinguish them from less promising ones. In particular, we explore the utility of various strategies that introduce highly polarizable moieties into the PI backbone to increase its RI yield. The derived insights provide a foundation for rational and targeted design that goes beyond traditional trial-and-error searches.</div>


2020 ◽  
Vol 17 (5) ◽  
pp. 716-724
Author(s):  
Yan A. Ivanenkov ◽  
Renat S. Yamidanov ◽  
Ilya A. Osterman ◽  
Petr V. Sergiev ◽  
Vladimir A. Aladinskiy ◽  
...  

Background: The key issue in the development of novel antimicrobials is a rapid expansion of new bacterial strains resistant to current antibiotics. Indeed, World Health Organization has reported that bacteria commonly causing infections in hospitals and in the community, e.g. E. Coli, K. pneumoniae and S. aureus, have high resistance vs the last generations of cephalosporins, carbapenems and fluoroquinolones. During the past decades, only few successful efforts to develop and launch new antibacterial medications have been performed. This study aims to identify new class of antibacterial agents using novel high-throughput screening technique. Methods: We have designed library containing 125K compounds not similar in structure (Tanimoto coeff.< 0.7) to that published previously as antibiotics. The HTS platform based on double reporter system pDualrep2 was used to distinguish between molecules able to block translational machinery or induce SOS-response in a model E. coli system. MICs for most active chemicals in LB and M9 medium were determined using broth microdilution assay. Results: In an attempt to discover novel classes of antibacterials, we performed HTS of a large-scale small molecule library using our unique screening platform. This approach permitted us to quickly and robustly evaluate a lot of compounds as well as to determine the mechanism of action in the case of compounds being either translational machinery inhibitors or DNA-damaging agents/replication blockers. HTS has resulted in several new structural classes of molecules exhibiting an attractive antibacterial activity. Herein, we report as promising antibacterials. Two most active compounds from this series showed MIC value of 1.2 (5) and 1.8 μg/mL (6) and good selectivity index. Compound 6 caused RFP induction and low SOS response. In vitro luciferase assay has revealed that it is able to slightly inhibit protein biosynthesis. Compound 5 was tested on several archival strains and exhibited slight activity against gram-negative bacteria and outstanding activity against S. aureus. The key structural requirements for antibacterial potency were also explored. We found, that the unsubstituted carboxylic group is crucial for antibacterial activity as well as the presence of bulky hydrophobic substituents at phenyl fragment. Conclusion: The obtained results provide a solid background for further characterization of the 5'- (carbonylamino)-2,3'-bithiophene-4'-carboxylate derivatives discussed herein as new class of antibacterials and their optimization campaign.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Takumi Kayukawa ◽  
Kenjiro Furuta ◽  
Keisuke Nagamine ◽  
Tetsuro Shinoda ◽  
Kiyoaki Yonesu ◽  
...  

Abstract Insecticide resistance has recently become a serious problem in the agricultural field. Development of insecticides with new mechanisms of action is essential to overcome this limitation. Juvenile hormone (JH) is an insect-specific hormone that plays key roles in maintaining the larval stage of insects. Hence, JH signaling pathway is considered a suitable target in the development of novel insecticides; however, only a few JH signaling inhibitors (JHSIs) have been reported, and no practical JHSIs have been developed. Here, we established a high-throughput screening (HTS) system for exploration of novel JHSIs using a Bombyx mori cell line (BmN_JF&AR cells) and carried out a large-scale screening in this cell line using a chemical library. The four-step HTS yielded 69 compounds as candidate JHSIs. Topical application of JHSI48 to B. mori larvae caused precocious metamorphosis. In ex vivo culture of the epidermis, JHSI48 suppressed the expression of the Krüppel homolog 1 gene, which is directly activated by JH-liganded receptor. Moreover, JHSI48 caused a parallel rightward shift in the JH response curve, suggesting that JHSI48 possesses a competitive antagonist-like activity. Thus, large-scale HTS using chemical libraries may have applications in development of future insecticides targeting the JH signaling pathway.


2020 ◽  
Author(s):  
Yuru Wang ◽  
Christopher D Katanski ◽  
Christopher Watkins ◽  
Jessica N Pan ◽  
Qing Dai ◽  
...  

Abstract AlkB is a DNA/RNA repair enzyme that removes base alkylations such as N1-methyladenosine (m1A) or N3-methylcytosine (m3C) from DNA and RNA. The AlkB enzyme has been used as a critical tool to facilitate tRNA sequencing and identification of mRNA modifications. As a tool, AlkB mutants with better reactivity and new functionalities are highly desired; however, previous identification of such AlkB mutants was based on the classical approach of targeted mutagenesis. Here, we introduce a high-throughput screening method to evaluate libraries of AlkB variants for demethylation activity on RNA and DNA substrates. This method is based on a fluorogenic RNA aptamer with an internal modified RNA/DNA residue which can block reverse transcription or introduce mutations leading to loss of fluorescence inherent in the cDNA product. Demethylation by an AlkB variant eliminates the blockage or mutation thereby restores the fluorescence signals. We applied our screening method to sites D135 and R210 in the Escherichia coli AlkB protein and identified a variant with improved activity beyond a previously known hyperactive mutant toward N1-methylguanosine (m1G) in RNA. We also applied our method to O6-methylguanosine (O6mG) modified DNA substrates and identified candidate AlkB variants with demethylating activity. Our study provides a high-throughput screening method for in vitro evolution of any demethylase enzyme.


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