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Open Access Publications from the University of California

Other Recent Work

Cover page of Identifying Allosteric Small-Molecule Binding Sites of Inactive NS2B-NS3 Proteases of Pathogenic Flaviviridae

Identifying Allosteric Small-Molecule Binding Sites of Inactive NS2B-NS3 Proteases of Pathogenic Flaviviridae

(2024)

Dengue, West Nile, Zika, Yellow fever, and Japanese encephalitis viruses persist as significant global health threats. The development of new therapeutic strategies based on inhibiting essential viral enzymes or viral–host protein interactions is problematic due to the fast mutation rate and rapid emergence of drug resistance. This study focuses on the NS2B-NS3 protease as a promising target for antiviral drug development. Promising allosteric binding sites were identified in two conformationally distinct inactive states and characterized for five flaviviruses and four Dengue virus subtypes. Their shapes, druggability, inter-viral similarity, sequence variation, and susceptibility to drug-resistant mutations have been studied. Two identified allosteric inactive state pockets appear to be feasible alternatives to a larger closed pocket near the active site, and they can be targeted with specific drug-like small-molecule inhibitors. Virus-specific sequence and structure implications and the feasibility of multi-viral inhibitors are discussed.

Cover page of Exploration and characterization of the antimalarial activity of cyclopropyl carboxamides that target the mitochondrial protein, cytochrome b.

Exploration and characterization of the antimalarial activity of cyclopropyl carboxamides that target the mitochondrial protein, cytochrome b.

(2024)

Drug resistance against antimalarials is rendering them increasingly ineffective and so there is a need for the development of new antimalarials. To discover new antimalarial chemotypes a phenotypic screen of the Janssen Jumpstarter library against the P. falciparum asexual stage was undertaken, uncovering the cyclopropyl carboxamide structural hit class. Structure-activity analysis revealed that each structural moiety was largely resistant to change, although small changes led to the frontrunner compound, WJM280, which has potent asexual stage activity (EC50 40 nM) and no human cell cytotoxicity. Forward genetics uncovered that cyclopropyl carboxamide resistant parasites have mutations and an amplification in the cytochrome b gene. Cytochrome b was then verified as the target with profiling against cytochrome b drug-resistant parasites and a mitochondrial oxygen consumption assay. Accordingly, the cyclopropyl carboxamide class was shown to have slow-acting asexual stage activity and activity against male gametes and exoerythrocytic forms. Enhancing metabolic stability to attain efficacy in malaria mouse models remains a challenge in the future development of this antimalarial chemotype.

Cover page of Tambjamines as Fast-Acting Multistage Antimalarials.

Tambjamines as Fast-Acting Multistage Antimalarials.

(2024)

Well-tolerated and novel antimalarials that can combat multiple stages of the parasite life cycle are desirable but challenging to discover and develop. Herein, we report results for natural product-inspired novel tambjamine antimalarials. We show that they are potent against liver, asexual erythrocytic, and sexual erythrocytic parasite life cycle stages. Notably, our lead candidate 1 (KAR425) displays excellent oral efficacy with complete clearance of parasites within 72 h of treatment in the humanized Plasmodium falciparum (NOD-scid) mouse model at 50 mg/kg × 4 days. Profiling of compound 1 demonstrated a fast in vitro killing profile. In addition, several other tambjamine analogues cured erythrocytic Plasmodium yoelii infections after oral doses of 30 and 50 mg/kg × 4 days in a murine model while exhibiting good safety and metabolic profiles. This study presents the first account of multiple-stage antiplasmodial activities with rapid killing profile in the tambjamine family.

Cover page of Open architecture of archaea MCM and dsDNA complexes resolved using monodispersed streptavidin affinity CryoEM.

Open architecture of archaea MCM and dsDNA complexes resolved using monodispersed streptavidin affinity CryoEM.

(2024)

The cryo-electron microscopy (cryoEM) method has enabled high-resolution structure determination of numerous biomolecules and complexes. Nevertheless, cryoEM sample preparation of challenging proteins and complexes, especially those with low abundance or with preferential orientation, remains a major hurdle. We developed an affinity-grid method employing monodispersed single particle streptavidin on a lipid monolayer to enhance particle absorption on the grid surface and alleviate sample exposure to the air-water interface. Using this approach, we successfully enriched the Thermococcus kodakarensis mini-chromosome maintenance complex 3 (MCM3) on cryoEM grids through biotinylation and resolved its structure. We further utilized this affinity method to tether the biotin-tagged dsDNA to selectively enrich a stable MCM3-ATP-dsDNA complex for cryoEM structure determination. Intriguingly, both MCM3 apo and dsDNA bound structures exhibit left-handed open spiral conformations, distinct from other reported MCM structures. The large open gate is sufficient to accommodate a dsDNA which could potentially be melted. The value of mspSA affinity method was further demonstrated by mitigating the issue of preferential angular distribution of HIV-1 capsid protein hexamer and RNA polymerase II elongation complex from Saccharomyces cerevisiae.

Cover page of Evaluating Antimalarial Proteasome Inhibitors for Efficacy in Babesia Blood Stage Cultures.

Evaluating Antimalarial Proteasome Inhibitors for Efficacy in Babesia Blood Stage Cultures.

(2024)

Tick-transmitted Babesia are a major global veterinary threat and an emerging risk to humans. Unlike their Plasmodium relatives, these erythrocyte-infecting Apicomplexa have been largely overlooked and lack specific treatment. Selective targeting of the Babesia proteasome holds promise for drug development. In this study, we screened a library of peptide epoxyketone inhibitors derived from the marine natural product carmaphycin B for their activity against Babesia. Several of these compounds showed activity against both the asexual and sexual blood stages of Plasmodium falciparum. These compounds inactivate β5 proteasome subunit activity in the lysates of Babesia divergens and Babesia microti in the low nanomolar range. Several compounds were tested with the purified B. divergens proteasome and showed IC50 values comparable to carfilzomib, an approved anticancer proteasome inhibitor. They also inhibited B. divergens growth in bovine erythrocyte cultures with solid EC50 values, but importantly, they appeared less toxic to human cells than carfilzomib. These compounds therefore offer a wider therapeutic window and provide new insights into the development of small proteasome inhibitors as selective drugs for babesiosis.

Cover page of Acute inflammation upregulates FAHFAs in adipose tissue and in differentiated adipocytes.

Acute inflammation upregulates FAHFAs in adipose tissue and in differentiated adipocytes.

(2024)

Since the discovery of fatty acid hydroxy fatty acids (FAHFAs), significant progress has been made in understanding their regulation, biochemistry, and physiological activities. Here, we contribute to this understanding by revealing that inflammation induces the production of fatty acid hydroxy stearic acids and fatty acid hydroxyoctadecadienoic acids in white adipose tissue depots and in adipocytes cocultured with macrophages. In lipopolysaccharide (LPS)-induced coculture systems, we confirm that adipose triglyceride lipase is required for inflammation-induced FAHFA generation and demonstrate that inflammation is necessary for producing hydroxy fatty acids. Chemically synthesized fatty acid hydroxyoctadecadienoic acids show anti-inflammatory activities in vivo, but only at supraphysiological concentrations. While endogenous FAHFAs are unlikely to be anti-inflammatory due to their low concentrations, conversion of proinflammatory hydroxy fatty acids into FAHFAs may dampen inflammation. Indeed, we demonstrate that proinflammatory lipids, such as hydroxyeicosatetraenoic acids (HETEs) and leukotriene B4 (LTB4), can be converted by cells in culture to weakly anti-inflammatory FAHFAs.

Cover page of Reduction of APOE accounts for neurobehavioral deficits in fetal alcohol spectrum disorders.

Reduction of APOE accounts for neurobehavioral deficits in fetal alcohol spectrum disorders.

(2024)

A hallmark of fetal alcohol spectrum disorders (FASD) is neurobehavioral deficits that still do not have effective treatment. Here, we present that reduction of Apolipoprotein E (APOE) is critically involved in neurobehavioral deficits in FASD. We show that prenatal alcohol exposure (PAE) changes chromatin accessibility of Apoe locus, and causes reduction of APOE levels in both the brain and peripheral blood in postnatal mice. Of note, postnatal administration of an APOE receptor agonist (APOE-RA) mitigates motor learning deficits and anxiety in those mice. Several molecular and electrophysiological properties essential for learning, which are altered by PAE, are restored by APOE-RA. Our human genome-wide association study further reveals that the interaction of PAE and a single nucleotide polymorphism in the APOE enhancer which chromatin is closed by PAE in mice is associated with lower scores in the delayed matching-to-sample task in children. APOE in the plasma is also reduced in PAE children, and the reduced level is associated with their lower cognitive performance. These findings suggest that controlling the APOE level can serve as an effective treatment for neurobehavioral deficits in FASD.

Cover page of Clearing the plate: a strategic approach to mitigate well-to-well contamination in large-scale microbiome studies.

Clearing the plate: a strategic approach to mitigate well-to-well contamination in large-scale microbiome studies.

(2024)

UNLABELLED: Large-scale studies are essential to answer questions about complex microbial communities that can be extremely dynamic across hosts, environments, and time points. However, managing acquisition, processing, and analysis of large numbers of samples poses many challenges, with cross-contamination being the biggest obstacle. Contamination complicates analysis and results in sample loss, leading to higher costs and constraints on mixed sample type study designs. While many researchers opt for 96-well plates for their workflows, these plates present a significant issue: the shared seal and weak separation between wells leads to well-to-well contamination. To address this concern, we propose an innovative high-throughput approach, termed as the Matrix method, which employs barcoded Matrix Tubes for sample acquisition. This method is complemented by a paired nucleic acid and metabolite extraction, utilizing 95% (vol/vol) ethanol to stabilize microbial communities and as a solvent for extracting metabolites. Comparative analysis between conventional 96-well plate extractions and the Matrix method, measuring 16S rRNA gene levels via quantitative polymerase chain reaction, demonstrates a notable decrease in well-to-well contamination with the Matrix method. Metagenomics, 16S rRNA gene amplicon sequencing (16S), and untargeted metabolomics analysis via liquid chromatography-tandem mass spectrometry (LC-MS/MS) confirmed that the Matrix method recovers reproducible microbial and metabolite compositions that can distinguish between subjects. This advancement is critical for large-scale study design as it minimizes well-to-well contamination and technical variation, shortens processing times, and integrates with automated infrastructure for enhancing sample randomization and metadata generation. IMPORTANCE: Understanding dynamic microbial communities typically requires large-scale studies. However, handling large numbers of samples introduces many challenges, with cross-contamination being a major issue. It not only complicates analysis but also leads to sample loss and increased costs and restricts diverse study designs. The prevalent use of 96-well plates for nucleic acid and metabolite extractions exacerbates this problem due to their wells having little separation and being connected by a single plate seal. To address this, we propose a new strategy using barcoded Matrix Tubes, showing a significant reduction in cross-contamination compared to conventional plate-based approaches. Additionally, this method facilitates the extraction of both nucleic acids and metabolites from a single tubed sample, eliminating the need to collect separate aliquots for each extraction. This innovation improves large-scale study design by shortening processing times, simplifying analysis, facilitating metadata curation, and producing more reliable results.

Cover page of A Review of Survey Instruments and Pharmacy Student Outcomes for Stress, Burnout, Depression and Anxiety.

A Review of Survey Instruments and Pharmacy Student Outcomes for Stress, Burnout, Depression and Anxiety.

(2024)

While the need to measure burnout, stress and mental health among pharmacy students has been emphasized in the literature, there is limited information on which validated scales should be used. The objective of this scoping review was to identify published studies that used validated scales for burnout, stress and mental health among pharmacy students to provide recommendations for implementation at schools/colleges of pharmacy. Thirty-two out of 153 articles published in the United States from 1 January 2000 to 30 September 2022 were included and categorized into studies measuring stress (20), burnout (4) and depression/anxiety (8). The most common validated scales used to assess stress and burnout among pharmacy students were the Perceived Stress Scale (PSS) and the Maslach Burnout Inventory and the Oldenburg Burnout Inventory, respectively. For mental health, anxiety was most commonly investigated using a variety of scales such as the Generalized Anxiety Disorder-7; the Patient Health Questionnaire, 9-item was used to measure depression in two studies. Validity, ease of use, cost and generalizability are important considerations for selecting a scale. The PSS has been studied extensively in pharmacy students and has been correlated with other well-being domains. Studies that measured burnout and mental health (specifically, depression and anxiety) have less published evidence among pharmacy students.

Cover page of Pregnancy Outcomes in Patients Treated with Upadacitinib: Analysis of Data from Clinical Trials and Postmarketing Reports.

Pregnancy Outcomes in Patients Treated with Upadacitinib: Analysis of Data from Clinical Trials and Postmarketing Reports.

(2024)

BACKGROUND AND OBJECTIVE: Upadacitinib is indicated for diseases affecting persons of childbearing potential including rheumatoid arthritis, psoriatic arthritis, axial spondyloarthritis, atopic dermatitis, Crohns disease, and ulcerative colitis; however, teratogenicity was observed in animal studies. Given the potential for human fetal risk, pregnancy avoidance measures were required during clinical trials. This analysis describes pregnancy outcomes in patients exposed to upadacitinib during pregnancy. METHODS: Clinical trial and postmarketing cases of in utero exposure to upadacitinib were identified in AbbVies safety database through 25 April, 2023. Analysis of clinical trial cases and postmarketing reports are presented separately; prospective and retrospectively reported pregnancy outcomes are integrated for each. Descriptive rates are presented to summarize outcomes. RESULTS: There were 128 maternal upadacitinib-exposed pregnancies with known outcomes identified; 80 and 48 pregnancies were reported in clinical trials and the postmarketing setting, respectively. In clinical trials (mean in utero exposure of 5 weeks, 3 days), live births (54%), spontaneous abortions (24%), elective terminations (21%), and ectopic pregnancy (1%) were reported. There was one report of a congenital malformation: a 35-week infant with an atrial septal defect. In postmarketing cases, live births (46%), spontaneous abortions (38%), elective terminations (15%), and ectopic pregnancy (2%) were reported. CONCLUSIONS: As the data are limited for in utero exposure to upadacitinib, definitive conclusions cannot be drawn regarding the effect of upadacitinib on pregnancy outcomes. Rates of adverse pregnancy outcomes with upadacitinib exposure were comparable to rates observed in the general population or patients with autoimmune inflammatory diseases. To date, no apparent evidence of teratogenicity exists in the analyses of human pregnancies exposed to upadacitinib during the first trimester.