Pyrocinchonimides Conjugate to Amine Groups on Proteins via Imide Transfer.

Advances in bioconjugation, the ability to link biomolecules to each other, small molecules, surfaces, and more, can spur the development of advanced materials and therapeutics. We have discovered that pyrocinchonimide, the dimethylated analogue of maleimide, undergoes a surprising transformation with biomolecules. The reaction targets amines and involves an imide transfer, which has not been previously reported for bioconjugation purposes. Despite their similarity to maleimides, pyrocinchonimides do not react with free thiols. Though both lysine residues and the N-termini of proteins can receive the transferred imide, the reaction also exhibits a marked preference for certain amines that cannot solely be ascribed to solvent accessibility. This property is peculiar among amine-targeting reactions and can reduce combinatorial diversity when many available reactive amines are available, such as in the formation of antibody-drug conjugates. Unlike amides, the modification undergoes very slow reversion under high pH conditions. The reaction offers a thermodynamically controlled route to single or multiple modifications of proteins for a wide range of applications.

Phase 1, randomized, parallel-group, double-blind, placebo-controlled trial to evaluate the effects of erenumab (AMG 334) and concomitant sumatriptan on blood pressure in healthy volunteers.

OBJECTIVES: The aim of this study was to assess the effects of concomitant administration of erenumab and sumatriptan on resting blood pressure, pharmacokinetics, safety, and tolerability in healthy subjects. METHODS: In this phase 1, parallel-group, one-way crossover, double-blind, placebo-controlled study, healthy adult subjects were randomized (1:2) to receive either intravenous placebo and subcutaneous sumatriptan 12 mg (i.e. two 6-mg injections separated by 1 hour) or intravenous erenumab 140 mg and subcutaneous sumatriptan 12 mg. Blood pressure was measured pre-dose and at prespecified times post-dose. The primary endpoint was individual time-weighted averages of mean arterial pressure, measured from 0 hours to 2.5 hours after the first dose of sumatriptan. Pharmacokinetic parameters for sumatriptan were evaluated by calculating geometric mean ratios (erenumab and sumatriptan/placebo and sumatriptan). Adverse events and anti-erenumab antibodies were also evaluated. RESULTS: A total of 34 subjects were randomized and included in the analysis. Least squares mean (standard error) time-weighted averages of mean arterial pressure were 87.4 (1.0) mmHg for the placebo and sumatriptan group and 87.4 (1.2) mmHg for the erenumab and sumatriptan group. Mean difference in mean arterial pressure between groups was -0.04 mmHg (90% confidence interval: -2.2, 2.1). Geometric mean ratio estimates for maximum plasma concentration of sumatriptan was 0.95 (90% confidence interval: 0.82, 1.09), area under the plasma concentration-time curve (AUC) from time 0 to 6 hours was 0.98 (90% confidence interval: 0.93, 1.03), and AUC from time 0 to infinity was 1.00 (90% confidence interval: 0.96, 1.05). No clinically relevant safety findings for co-administration of sumatriptan and erenumab were identified. CONCLUSION: Co-administration of erenumab and sumatriptan had no additional effect on resting blood pressure or on pharmacokinetics of sumatriptan. Trial registration: ClinicalTrials.gov, NCT02741310.

First-in-human development of a pharmacodynamic biomarker for PAC1 receptor antagonists using intradermal injections of maxadilan.

Maxadilan, a potent vasodilator peptide, selectively activates the PAC1 receptor, a promising target for migraine therapy. Therefore, maxadilan has been suggested as a tool to study the pharmacodynamics (PDs) of PAC1 receptor antagonists. The objectives of this first-in-human study were to: (1) determine the safety, tolerability, dose response, and time course of the dermal blood flow (DBF) changes after intradermal (i.d.) injections of maxadilan in the human forearm, and (2) assess the inter-arm and inter-period reproducibility of this response. This was a single-center, open-label study in healthy subjects, comprising three parts: (1) dose-response (n = 25), (2) response duration (n = 10), and (3) reproducibility (n = 15). DBF measurements were performed using laser Doppler imaging (LDI) up to 60 min postinjection, or up to 5 days for the response duration assessments. To assess reproducibility, the intraclass correlation coefficient (ICC) and sample sizes were calculated. The i.d. maxadilan (0.001, 0.01, 0.1, 0.9, 3, and 10 ng) produced a well-tolerated, dose-dependent increase in DBF, with a half-maximal effective concentration fitted at 0.0098 ng. The DBF response to 0.9 ng maxadilan was quantifiable with LDI up to 72 h postinjection. The inter-period reproducibility of the DBF response was better upon 0.9 ng (ICC > 0.6) compared to 0.01 ng (ICC < 0.4) maxadilan. However, irrespective of the study design or maxadilan dose, a sample size of 11 subjects is sufficient to detect a 30% difference in DBF response with 80% power. In conclusion, intradermal maxadilan provides a safe, well-tolerated, and reproducible PD biomarker for PAC1 receptor antagonists in vivo in humans.

Single-molecule Taq DNA polymerase dynamics.

Taq DNA polymerase functions at elevated temperatures with fast conformational dynamics-regimes previously inaccessible to mechanistic, single-molecule studies. Here, single-walled carbon nanotube transistors recorded the motions of Taq molecules processing matched or mismatched template-deoxynucleotide triphosphate pairs from 22° to 85°C. By using four enzyme orientations, the whole-enzyme closures of nucleotide incorporations were distinguished from more rapid, 20-µs closures of Taq's fingers domain testing complementarity and orientation. On average, one transient closure was observed for every nucleotide binding event; even complementary substrate pairs averaged five transient closures between each catalytic incorporation at 72°C. The rate and duration of the transient closures and the catalytic events had almost no temperature dependence, leaving all of Taq's temperature sensitivity to its rate-determining open state.

Predicting COVID-19 Severity with a Specific Nucleocapsid Antibody plus Disease Risk Factor Score.

Effective methods for predicting COVID-19 disease trajectories are urgently needed. Here, enzyme-linked immunosorbent assay (ELISA) and coronavirus antigen microarray (COVAM) analysis mapped antibody epitopes in the plasma of COVID-19 patients (n = 86) experiencing a wide range of disease states. The experiments identified antibodies to a 21-residue epitope from nucleocapsid (termed Ep9) associated with severe disease, including admission to the intensive care unit (ICU), requirement for ventilators, or death. Importantly, anti-Ep9 antibodies can be detected within 6 days post-symptom onset and sometimes within 1 day. Furthermore, anti-Ep9 antibodies correlate with various comorbidities and hallmarks of immune hyperactivity. We introduce a simple-to-calculate, disease risk factor score to quantitate each patient's comorbidities and age. For patients with anti-Ep9 antibodies, scores above 3.0 predict more severe disease outcomes with a 13.42 likelihood ratio (96.7% specificity). The results lay the groundwork for a new type of COVID-19 prognostic to allow early identification and triage of high-risk patients. Such information could guide more effective therapeutic intervention.IMPORTANCE The COVID-19 pandemic has resulted in over two million deaths worldwide. Despite efforts to fight the virus, the disease continues to overwhelm hospitals with severely ill patients. Diagnosis of COVID-19 is readily accomplished through a multitude of reliable testing platforms; however, prognostic prediction remains elusive. To this end, we identified a short epitope from the SARS-CoV-2 nucleocapsid protein and also a disease risk factor score based upon comorbidities and age. The presence of antibodies specifically binding to this epitope plus a score cutoff can predict severe COVID-19 outcomes with 96.7% specificity.

Predicting COVID-19 Severity with a Specific Nucleocapsid Antibody plus Disease Risk Factor Score.

Effective methods for predicting COVID-19 disease trajectories are urgently needed. Here, ELISA and coronavirus antigen microarray (COVAM) analysis mapped antibody epitopes in the plasma of COVID-19 patients (n = 86) experiencing a wide-range of disease states. The experiments identified antibodies to a 21-residue epitope from nucleocapsid (termed Ep9) associated with severe disease, including admission to the ICU, requirement for ventilators, or death. Importantly, anti-Ep9 antibodies can be detected within six days post-symptom onset and sometimes within one day. Furthermore, anti-Ep9 antibodies correlate with various comorbidities and hallmarks of immune hyperactivity. We introduce a simple-to-calculate, disease risk factor score to quantitate each patients comorbidities and age. For patients with anti-Ep9 antibodies, scores above 3.0 predict more severe disease outcomes with a 13.42 Likelihood Ratio (96.7% specificity). The results lay the groundwork for a new type of COVID-19 prognostic to allow early identification and triage of high-risk patients. Such information could guide more effective therapeutic intervention.

A Multi-Center, Open-Label, Pharmacokinetic Drug Interaction Study of Erenumab and a Combined Oral Contraceptive in Healthy Females.

BACKGROUND: Erenumab is a human anti-calcitonin gene-related peptide monoclonal antibody developed for migraine prevention. Migraine predominately affects women of childbearing age; thus, it is important to determine potential drug-drug interactions between a common oral contraceptive and drugs used to treat migraine. OBJECTIVES: We sought to evaluate potential drug-drug interactions between erenumab and a common oral contraceptive. METHODS: Healthy women received three cycles of a norgestimate/ethinyl estradiol-containing oral contraceptive with a single 140-mg subcutaneous dose of erenumab during cycle three. Norgestimate metabolites (norgestrel and norelgestromin) and ethinyl estradiol pharmacokinetics were evaluated in the absence and presence of erenumab. Primary endpoint was peak plasma concentration (Cmax) and area under concentration-time curve from time 0 to 24 h (AUCtau). Luteinizing hormone, follicle-stimulating hormone, and progesterone concentrations were evaluated as pharmacodynamic markers. RESULTS: Erenumab did not influence the pharmacokinetics of norelgestromin, norgestrel, or ethinyl estradiol. Least-squares mean estimates (90% confidence interval) for Cmax ratios were 1.05 (0.90-1.23), 1.06 (0.97-1.16), and 1.04 (0.88-1.22) for norelgestromin, norgestrel, and ethinyl estradiol, respectively. Respective AUCtau ratios were 1.02 (0.94-1.12), 1.03 (0.96-1.10), and 1.02 (0.91-1.14). Luteinizing hormone, follicle-stimulating hormone, and progesterone concentrations were similar after exposure to oral contraceptive alone and with erenumab. CONCLUSION: Erenumab did not alter the pharmacokinetics of the active components of an estrogen/progestin combination oral contraceptive. Thus, no change in contraceptive efficacy is expected with erenumab. TRIAL REGISTRATION: ClinicalTrials.gov NCT02792517.

Correction to: A Multi­Center, Open­Label, Pharmacokinetic Drug Interaction Study of Erenumab and a Combined Oral Contraceptive in Healthy Females.

The authors would like to correct the error in the publication of the original article. The correction detail is given below.

Reduced TRPM8 expression underpins reduced migraine risk and attenuated cold pain sensation in humans.

Multiple genome-wide association studies have identified non-coding single-nucleotide variants (SNVs) near (e.g., rs10166942[C]) or within (rs17862920[T]) the TRPM8 gene that encodes a cold thermosensor is associated with reduced migraine risk. Furthermore, rs10166942[C]) and rs10166942[T]) are more prevalent in populations that reside in hotter and colder climates, respectively. Here we assessed whether these alleles affect TRPM8 expression in humans and human physiologic responses to cold challenge. Here we show that TRPM8 expression is decreased from the chromosome harboring the rs10166942[C] allele in the human dorsal root ganglia. Moreover, carriers of rs10166942[C] required significantly lower temperatures and longer duration of exposure to reach a cold pain threshold (CPTh), which correlated with decreased TRPM8 expression expected in the carriers. This study provides evidence for a genotype-dependent influence on cold pain sensation suggesting that carriers of the reduced migraine risk allele have reduced sensitivity to cold stimuli and that TRPM8 acts as a cold thermosensor and cold pain transducer in humans. Reduced TRPM8 expression and function underpins the migraine protection in carriers of rs10166942[C]; thus, the evaluation of TRPM8 antagonists as migraine therapeutics is warranted. Furthermore, these results provide mechanistic insights for evolutionary positive selection of rs10166942[T] allele in adaptation along latitudinal cline to colder climates.

Mutually Orthogonal DNA Replication Systems In Vivo.

The yeast cytoplasmically localized pGKL1/TP-DNAP1 plasmid/DNA polymerase pair forms an orthogonal DNA replication system whose mutation rate can be drastically increased without influencing genomic replication, thereby supporting in vivo continuous evolution. Here, we report that the pGKL2/TP-DNAP2 plasmid/DNA polymerase pair forms a second orthogonal replication system. We show that custom genes can be encoded and expressed from pGKL2, that error-prone TP-DNAP2s can be engineered, and that pGKL2 replication by TP-DNAP2 is both orthogonal to genomic replication in Saccharomyces cerevisiae and mutually orthogonal with pGKL1 replication by TP-DNAP1. This demonstration of two mutually orthogonal DNA replication systems with tunable error rates and properties should enable new applications in cell-based continuous evolution, genetic recording, and synthetic biology at large.

Association and regulation of protein factors of field effect in prostate tissues.

Field effect or field cancerization denotes the presence of molecular aberrations in structurally intact cells residing in histologically normal tissues adjacent to solid tumors. Currently, the etiology of prostate field­effect formation is unknown and there is a prominent lack of knowledge of the underlying cellular and molecular pathways. We have previously identified an upregulated expression of several protein factors representative of prostate field effect, i.e., early growth response-1 (EGR­1), platelet-derived growth factor­A (PDGF­A), macrophage inhibitory cytokine­1 (MIC­1), and fatty acid synthase (FASN) in tissues at a distance of 1 cm from the visible margin of intracapsule prostate adenocarcinomas. We have hypothesized that the transcription factor EGR­1 could be a key regulator of prostate field­effect formation by controlling the expression of PDGF­A, MIC­1, and FASN. Taking advantage of our extensive quantitative immunofluorescence data specific for EGR­1, PDGF­A, MIC­1, and FASN generated in disease­free, tumor­adjacent, and cancerous human prostate tissues, we chose comprehensive correlation as our major approach to test this hypothesis. Despite the static nature and sample heterogeneity of association studies, we show here that sophisticated data generation, such as by spectral image acquisition, linear unmixing, and digital quantitative imaging, can provide meaningful indications of molecular regulations in a physiologically relevant in situ environment. Our data suggest that EGR­1 acts as a key regulator of prostate field effect through induction of pro­proliferative (PDGF­A and FASN), and suppression of pro­apoptotic (MIC­1) factors. These findings were corroborated by computational promoter analyses and cell transfection experiments in non­cancerous prostate epithelial cells with ectopically induced and suppressed EGR­1 expression. Among several clinical applications, a detailed knowledge of pathways of field effect may lead to the development of targeted intervention strategies preventing progression from pre-malignancy to cancer.

Metastatic spinal cord compression by solid tumors.

As the survival of cancer patients continues to improve, physicians in the 21st century face the challenge of early detection of metastatic spinal cord compression. Prompt diagnosis and intervention increase the likelihood of functional recovery. Because the epidural space is the most common site of spinal cord metastasis from solid tumors, this article will review the epidemiology, relevant anatomy, pathophysiology, clinical presentation, diagnostic evaluation, treatment, and prognosis for metastatic epidural spinal cord compression. Special attention will be given to the various modalities available for management of metastatic epidural spinal cord compression to maintain or restore normal spinal cord function and relieve pain. These treatment options will be considered according to patients' disease burden, life expectancy, and values. Intramedullary metastasis will be briefly discussed.