Oct1 regulates trophoblast development during early mouse embryogenesis.

Oct1 (Pou2f1) is a transcription factor of the POU-homeodomain family that is unique in being ubiquitously expressed in both embryonic and adult mouse tissues. Although its expression profile suggests a crucial role in multiple regions of the developing organism, the only essential function demonstrated so far has been the regulation of cellular response to oxidative and metabolic stress. Here, we describe a loss-of-function mouse model for Oct1 that causes early embryonic lethality, with Oct1-null embryos failing to develop beyond the early streak stage. Molecular and morphological analyses of Oct1 mutant embryos revealed a failure in the establishment of a normal maternal-embryonic interface due to reduced extra-embryonic ectoderm formation and lack of the ectoplacental cone. Oct1(-/-) blastocysts display proper segregation of trophectoderm and inner cell mass lineages. However, Oct1 loss is not compatible with trophoblast stem cell derivation. Importantly, the early gastrulation defect caused by Oct1 disruption can be rescued in a tetraploid complementation assay. Oct1 is therefore primarily required for the maintenance and differentiation of the trophoblast stem cell compartment during early post-implantation development. We present evidence that Cdx2, which is expressed at high levels in trophoblast stem cells, is a direct transcriptional target of Oct1. Our data also suggest that Oct1 is required in the embryo proper from late gastrulation stages onwards.

IMI2-PainCare-BioPain-RCT1: study protocol for a randomized, double-blind, placebo-controlled, crossover, multi-center trial in healthy subjects to investigate the effects of lacosamide, pregabalin, and tapentadol on biomarkers of pain processing observed by peripheral nerve excitability testing (NET).

BACKGROUND: Few new drugs have been developed for chronic pain. Drug development is challenged by uncertainty about whether the drug engages the human target sufficiently to have a meaningful pharmacodynamic effect. IMI2-PainCare-BioPain-RCT1 is one of four similarly designed studies that aim to link different functional biomarkers of drug effects on the nociceptive system that could serve to accelerate the future development of analgesics. This study focusses on biomarkers derived from nerve excitability testing (NET) using threshold tracking of the peripheral nervous system. METHODS: This is a multisite single-dose, subject and assessor-blind, randomized, placebo-controlled, 4-period, 4-way crossover, pharmacodynamic (PD), and pharmacokinetic (PK) study in healthy subjects. Biomarkers derived from NET of large sensory and motor fibers and small sensory fibers using perception threshold tracking will be obtained before and three times after administration of three medications known to act on the nociceptive system (lacosamide, pregabalin, tapentadol) and placebo, given as a single oral dose with at least 1 week apart. Motor and sensory NET will be assessed on the right wrist in a non-sensitized normal condition while perception threshold tracking will be performed bilaterally on both non-sensitized and sensitized forearm skin. Cutaneous high-frequency electrical stimulation is used to induce hyperalgesia. Blood samples will be taken for pharmacokinetic purposes and pain ratings as well as predictive psychological traits will be collected. A sequentially rejective multiple testing approach will be used with overall alpha error of the primary analysis split across the two primary outcomes: strength-duration time constant (SDTC; a measure of passive membrane properties and nodal persistent Na+ conductance) of large sensory fibers and SDTC of large motor fibers comparing lacosamide and placebo. The key secondary endpoint is the SDTC measured in small sensory fibers. Remaining treatment arm effects on key NET outcomes and PK modelling are other prespecified secondary or exploratory analyses. DISCUSSION: Measurements of NET using threshold tracking protocols are sensitive to membrane potential at the site of stimulation. Sets of useful indices of axonal excitability collectively may provide insights into the mechanisms responsible for membrane polarization, ion channel function, and activity of ionic pumps during the process of impulse conduction. IMI2-PainCare-BioPain-RCT1 hypothesizes that NET can serve as biomarkers of target engagement of analgesic drugs in this compartment of the nociceptive system for future Phase 1 clinical trials. Phase 2 and 3 clinical trials could also benefit from these tools for patient stratification. TRIAL REGISTRATION: This trial was registered 25/06/2019 in EudraCT ( 2019-000942-36 ).

IMI2-PainCare-BioPain-RCT2 protocol: a randomized, double-blind, placebo-controlled, crossover, multicenter trial in healthy subjects to investigate the effects of lacosamide, pregabalin, and tapentadol on biomarkers of pain processing observed by non-invasive neurophysiological measurements of human spinal cord and brainstem activity.

BACKGROUND: IMI2-PainCare-BioPain-RCT2 is one of four similarly designed clinical studies aiming at profiling a set of functional biomarkers of drug effects on specific compartments of the nociceptive system that could serve to accelerate the future development of analgesics. IMI2-PainCare-BioPain-RCT2 will focus on human spinal cord and brainstem activity using biomarkers derived from non-invasive neurophysiological measurements. METHODS: This is a multisite, single-dose, double-blind, randomized, placebo-controlled, 4-period, 4-way crossover, pharmacodynamic (PD) and pharmacokinetic (PK) study in healthy subjects. Neurophysiological biomarkers of spinal and brainstem activity (the RIII flexion reflex, the N13 component of somatosensory evoked potentials (SEP) and the R2 component of the blink reflex) will be recorded before and at three distinct time points after administration of three medications known to act on the nociceptive system (lacosamide, pregabalin, tapentadol), and placebo, given as a single oral dose in separate study periods. Medication effects on neurophysiological measures will be assessed in a clinically relevant hyperalgesic condition (high-frequency electrical stimulation of the skin), and in a non-sensitized normal condition. Patient-reported outcome measures (pain ratings and predictive psychological traits) will also be collected; and blood samples will be taken for pharmacokinetic modelling. A sequentially rejective multiple testing approach will be used with overall alpha error of the primary analysis split between the two primary endpoints, namely the percentage amplitude changes of the RIII area and N13 amplitude under tapentadol. Remaining treatment arm effects on RIII, N13 and R2 recovery cycle are key secondary confirmatory analyses. Complex statistical analyses and PK-PD modelling are exploratory. DISCUSSION: The RIII component of the flexion reflex is a pure nociceptive spinal reflex widely used for investigating pain processing at the spinal level. It is sensitive to different experimental pain models and to the antinociceptive activity of drugs. The N13 is mediated by large myelinated non-nociceptive fibers and reflects segmental postsynaptic response of wide dynamic range dorsal horn neurons at the level of cervical spinal cord, and it could be therefore sensitive to the action of drugs specifically targeting the dorsal horn. The R2 reflex is mediated by large myelinated non-nociceptive fibers, its circuit consists of a polysynaptic chain lying in the reticular formation of the pons and medulla. The recovery cycle of R2 is widely used for assessing brainstem excitability. For these reasons, IMI2-PainCare-BioPain-RCT2 hypothesizes that spinal and brainstem neurophysiological measures can serve as biomarkers of target engagement of analgesic drugs for future Phase 1 clinical trials. Phase 2 and 3 clinical trials could also benefit from these tools for patient stratification. TRIAL REGISTRATION: This trial was registered on 02 February 2019 in EudraCT ( 2019-000755-14 ).

IMI2-PainCare-BioPain-RCT3: a randomized, double-blind, placebo-controlled, crossover, multi-center trial in healthy subjects to investigate the effects of lacosamide, pregabalin, and tapentadol on biomarkers of pain processing observed by electroencephalography (EEG).

BACKGROUND: IMI2-PainCare-BioPain-RCT3 is one of four similarly designed clinical studies aiming at profiling a set of functional biomarkers of drug effects on the nociceptive system that could serve to accelerate the future development of analgesics, by providing a quantitative understanding between drug exposure and effects of the drug on nociceptive signal processing in human volunteers. IMI2-PainCare-BioPain-RCT3 will focus on biomarkers derived from non-invasive electroencephalographic (EEG) measures of brain activity. METHODS: This is a multisite single-dose, double-blind, randomized, placebo-controlled, 4-period, 4-way crossover, pharmacodynamic (PD) and pharmacokinetic (PK) study in healthy subjects. Biomarkers derived from scalp EEG measurements (laser-evoked brain potentials [LEPs], pinprick-evoked brain potentials [PEPs], resting EEG) will be obtained before and three times after administration of three medications known to act on the nociceptive system (lacosamide, pregabalin, tapentadol) and placebo, given as a single oral dose in separate study periods. Medication effects will be assessed concurrently in a non-sensitized normal condition and a clinically relevant hyperalgesic condition (high-frequency electrical stimulation of the skin). Patient-reported outcomes will also be collected. A sequentially rejective multiple testing approach will be used with overall alpha error of the primary analysis split between LEP and PEP under tapentadol. Remaining treatment arm effects on LEP or PEP or effects on EEG are key secondary confirmatory analyses. Complex statistical analyses and PK-PD modeling are exploratory. DISCUSSION: LEPs and PEPs are brain responses related to the selective activation of thermonociceptors and mechanonociceptors. Their amplitudes are dependent on the responsiveness of these nociceptors and the state of the pathways relaying nociceptive input at the level of the spinal cord and brain. The magnitude of resting EEG oscillations is sensitive to changes in brain network function, and some modulations of oscillation magnitude can relate to perceived pain intensity, variations in vigilance, and attentional states. These oscillations can also be affected by analgesic drugs acting on the central nervous system. For these reasons, IMI2-PainCare-BioPain-RCT3 hypothesizes that EEG-derived measures can serve as biomarkers of target engagement of analgesic drugs for future Phase 1 clinical trials. Phase 2 and 3 clinical trials could also benefit from these tools for patient stratification. TRIAL REGISTRATION: This trial was registered 25/06/2019 in EudraCT ( 2019%2D%2D001204-37 ).

Oct1 is required for mTOR-induced G1 cell cycle arrest via the control of p27(Kip1) expression.

Oct1 is a ubiquitously expressed transcription factor that is induced in response to DNA damage to modulate gene expression. Herein, Oct1 deficient mouse embryonic fibroblasts were used as a model to study the importance of Oct1 in cellular stress response. Cells lacking Oct1 kept proliferating and bypassed the G(1) cell cycle arrest induced by glucose or amino acid starvation. Indeed, mTOR-mediated regulation of proliferation was abolished in Oct1(-/-) cells starved for glucose or amino acids and Oct1(-/-) cells were also insensitive to mTOR inhibition by rapamycin. Furthermore, in wild-type cells, Oct1 controls the transcription of the CDK inhibitor p27(Kip1) downstream of the mTOR pathway and Oct1-null cells failed to upregulate p27(Kip1) in response to rapamycin or glucose starvation. p27(Kip1) is required for rapamycin or nutrient starvation-induced G(1)-arrest, as p27(-/-) fibroblasts were largely insensitive to rapamycin treatment or glucose starvation. Thus, Oct1 appears to be a critical mediator of the growth arrest induced by mTOR inhibition via the control of p27(Kip1) expression.

The OBF-1 gene locus confers B cell-specific transcription by restricting the ubiquitous activity of its promoter.

Transcription of the gene encoding the transcriptional coactivator Oct-binding factor 1 (OBF-1)/OCA-B/Bob.1 is largely restricted to B cells. During B cell development OBF-1 expression shows two peaks, one in immature B cells in the bone marrow and the other in germinal center B cells. Promoter analysis has identified a cAMP response element (CRE)-binding site present in the OBF-1 proximal promoter that is crucial for activity in B cells and for the induction of OBF-1 expression upon stimulation with CD40 ligand/IL-4. Here we address the question of how transcription of the OBF-1 gene is restricted to B cells. Surprisingly, in transient transfection assays the OBF-1 proximal promoter exhibited an equally strong activity in B and non-B cells. In contrast, upstream promoter regions displayed B cell-specific properties, partly overlapping with DNaseI hypersensitive sites identified in this study. In mice, expression of a neomycin resistance gene under the control of a Polyoma enhancer/TK promoter cassette was restricted to B cells when integrated into the OBF-1 locus, but was ubiquitous when integrated into two other loci, Oct-1 or the large subunit of RNA polymerase II.Therefore, lineage commitment of the OBF-1 gene is promoter independent and is achieved by regulating the entire locus in a B cell-specific manner.