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1.
ACS Pharmacol Transl Sci ; 7(5): 1252-1261, 2024 May 10.
Article in English | MEDLINE | ID: mdl-38751631

ABSTRACT

Hepatorenal syndrome (HRS) is a life-threatening complication of end-stage liver disease first reported over a century ago, but its management still poses an unmet challenge. A therapeutic agent found to stabilize the condition is a short cyclic peptide, vasopressin analogue, terlipressin (TP). While TP is commonly prescribed for HRS patients in most parts of the world, it was only recently approved for use in the United States. TP exhibits short circulation half-lives and adverse side effects associated with the dose required. Herein, we present a 1,18-octadecanedioic acid (ODDA) conjugate of the cyclic peptide (ODDA-TP), which enables noncovalent binding to serum albumin via native fatty acid binding modes. ODDA-TP is demonstrated to outperform TP alone in studies including in vitro cellular receptor activation, stability in plasma, pharmacokinetics, and performance in vivo in rats. Specifically, ODDA-TP had an elimination half-life 20 times that of TP alone while exhibiting a superior safety profile.

2.
J Am Pharm Assoc (2003) ; 64(1): 34-38.e1, 2024.
Article in English | MEDLINE | ID: mdl-37865310

ABSTRACT

As the U.S. population becomes more racially and ethnically diverse, it is increasingly important to characterize health inequities for targeted intervention. As it stands, demographic data regarding race and ethnicity for patients and pharmacy trainees alike are aggregated into heterogenous population groups, resulting in findings that may inaccurately reflect the experiences of smaller subgroups. Disaggregation of patient outcomes data can serve to better inform public health interventions for the most vulnerable populations. In pharmacy, disaggregation can allow for better identification of racial and ethnic subgroups who have been traditionally excluded from funding support among other opportunities. In this commentary, we provide historical context and actionable recommendations to better describe our patient and pharmacy trainee populations, with the objectives of improving pharmacist representation and health equity.


Subject(s)
Pharmaceutical Services , Pharmacists , Humans , Data Aggregation , Ethnicity , Delivery of Health Care
3.
J Foot Ankle Surg ; 63(2): 145-150, 2024.
Article in English | MEDLINE | ID: mdl-37805097

ABSTRACT

The presence of severe coronal plane deformity in the ankle joint is widely recognized as challenging to correct by total ankle joint arthroplasty alone, necessitating additional rearfoot fusion. The primary aim of this retrospective study was to investigate the potential associations between the presence or severity of coronal tibiotalar deformities and adverse outcomes after isolated total ankle arthroplasty, such as revisions and complications. The secondary aim was to analyze the potential associations between comorbidities, demographics, and implant types, and adverse outcomes. Our study's distinctive feature was its exclusive concentration on patients with deformities centralized in the ankle joint. Chart review was performed on 496 ankles in 456 patients who had a total ankle arthroplasty by 5 surgeons from 1/1/2010 to 12/31/2019. After exclusion and inclusion criteria were applied, total of 214 ankles in 210 patients were included for data analysis. At a mean follow-up period of 3 ± 2.0 years, our cohort had 15 (7.0%) revisions and 15 (7.0%) complications. Multivariable logistic regression model showed that the presence or severity of the coronal deformity was not significantly associated with incidences of revisions or complications. Female patients had significantly lower revision rate. Otherwise, the differences in age, race, body mass index, tobacco use, presence of diabetes, chronic kidney disease, atrial fibrillation, length of surgery, or type of implant were not significantly associated with incidences of revisions or complications. Further study could be performed to analyze the extent and duration that the coronal deformity correction is maintained after total ankle arthroplasty as well as the effect of each soft tissue procedure performed with the total ankle arthroplasty.


Subject(s)
Arthroplasty, Replacement, Ankle , Joint Prosthesis , Humans , Female , Ankle Joint/surgery , Ankle/surgery , Retrospective Studies , Arthroplasty, Replacement, Ankle/adverse effects , Arthroplasty, Replacement, Ankle/methods , Treatment Outcome
4.
Am J Pharm Educ ; 87(6): 100080, 2023 06.
Article in English | MEDLINE | ID: mdl-37316141

ABSTRACT

Until now, the term "advocacy" in pharmacy education and practice has focused on advocating for the advancement of the pharmacy profession or patient advocacy. With the 2022 Curricular Outcomes and Entrustable Professional Activities publication, the focus of advocacy has broadened to include advocacy for other causes that impact the health of patients. This commentary will highlight 3 pharmacy-focused organizations advocating for social issues impacting the health of patients as well as encourage members of the Academy to continue to expand personal social advocacy efforts.


Subject(s)
Education, Pharmacy , Pharmaceutical Services , Pharmacies , Humans , Academies and Institutes , Patient Advocacy
6.
J Am Pharm Assoc (2003) ; 62(3): 701-705, 2022.
Article in English | MEDLINE | ID: mdl-35367143

ABSTRACT

Due to the effects of structural racism, disproportionately lower numbers of Black, Hispanic or LatinX, American Indian, and Alaska Native students pursue a career in pharmacy and successfully matriculate into the profession. Despite these disparities being present for many years, little progress has been achieved in diversifying the pharmacy profession, resulting in a persistent lack of diversity within pharmacy leadership across employers and pharmacy organizations. Consistent with recent recommendations for improving diversity in pharmacy, the PharmGradWishlist (PGWL) initiative was created as a way for practicing pharmacists and organizations to provide direct financial sponsorship to racially and ethnically minoritized trainees to offset costs incurred during training and during the transition from student to practicing pharmacist. Many of these costs, such as residency and fellowship application fees, job interview travel costs, board exam and licensing fees, and moving expenses, are not typically subsidized by federal student funding. Offsetting these costs is an important way to reduce barriers to entering the profession and postgraduate training, the latter of which may be particularly important in trainees' pursuit of academic and leadership positions in pharmacy. The initial development and advertisement of the initiative occurred through social media and the grassroots efforts of the PGWL team, a group of 10 volunteer pharmacists from across the country, and resulted in generous donations from a small proportion of practicing pharmacists nationwide. It is now time for the profession as a whole to embrace the role of direct sponsorship in improving diversity in the profession. We call upon pharmacists and pharmacy organizations to advocate for and participate in financial sponsorship of racially and ethnically minoritized trainees and pharmacists as a way to increase diversity and promote health equity.


Subject(s)
Education, Pharmacy , Pharmacy , Students, Pharmacy , Health Promotion , Humans , Pharmacists
7.
Sci Transl Med ; 13(584)2021 03 10.
Article in English | MEDLINE | ID: mdl-33692132

ABSTRACT

Glioblastoma (GBM) is one of the most difficult cancers to effectively treat, in part because of the lack of precision therapies and limited therapeutic access to intracranial tumor sites due to the presence of the blood-brain and blood-tumor barriers. We have developed a precision medicine approach for GBM treatment that involves the use of brain-penetrant RNA interference-based spherical nucleic acids (SNAs), which consist of gold nanoparticle cores covalently conjugated with radially oriented and densely packed small interfering RNA (siRNA) oligonucleotides. On the basis of previous preclinical evaluation, we conducted toxicology and toxicokinetic studies in nonhuman primates and a single-arm, open-label phase 0 first-in-human trial (NCT03020017) to determine safety, pharmacokinetics, intratumoral accumulation and gene-suppressive activity of systemically administered SNAs carrying siRNA specific for the GBM oncogene Bcl2Like12 (Bcl2L12). Patients with recurrent GBM were treated with intravenous administration of siBcl2L12-SNAs (drug moniker: NU-0129), at a dose corresponding to 1/50th of the no-observed-adverse-event level, followed by tumor resection. Safety assessment revealed no grade 4 or 5 treatment-related toxicities. Inductively coupled plasma mass spectrometry, x-ray fluorescence microscopy, and silver staining of resected GBM tissue demonstrated that intravenously administered SNAs reached patient tumors, with gold enrichment observed in the tumor-associated endothelium, macrophages, and tumor cells. NU-0129 uptake into glioma cells correlated with a reduction in tumor-associated Bcl2L12 protein expression, as indicated by comparison of matched primary tumor and NU-0129-treated recurrent tumor. Our results establish SNA nanoconjugates as a potential brain-penetrant precision medicine approach for the systemic treatment of GBM.


Subject(s)
Brain Neoplasms , Glioblastoma , Metal Nanoparticles , Nucleic Acids , Brain Neoplasms/genetics , Brain Neoplasms/therapy , Glioblastoma/genetics , Glioblastoma/therapy , Gold , Humans , Muscle Proteins/metabolism , Neoplasm Recurrence, Local , Proto-Oncogene Proteins c-bcl-2/genetics , Proto-Oncogene Proteins c-bcl-2/metabolism , RNA Interference
8.
Mol Pharm ; 16(10): 4223-4229, 2019 10 07.
Article in English | MEDLINE | ID: mdl-31536368

ABSTRACT

The effects of spherical nucleic acid (SNA) gold nanoparticle conjugates on the activation of macrophages in vitro and release of cytokines in vivo were explored. Herein, we show that G-quadruplexes, the formation of which is enhanced on gold nanoparticle surfaces, elicit an increase in cytokine release from mouse and human macrophages and induce the upregulation of activation receptors as well as NO2 production in vitro. Moreover, these G-rich SNAs can induce cytokine release when injected intravenously, though there were no severe, long-term effects observed. These results further reinforce the notion that nucleic acid sequence and structure play an important role in how SNAs interact in biological milieu and highlight a key design parameter.


Subject(s)
G-Quadruplexes , Gold/chemistry , Macrophage Activation/drug effects , Macrophages/metabolism , Metal Nanoparticles/administration & dosage , Nucleic Acids/chemistry , Animals , Cells, Cultured , Cytokines/metabolism , Humans , In Vitro Techniques , Macrophages/drug effects , Metal Nanoparticles/chemistry , Mice , Mice, Inbred C57BL , Nitrogen Dioxide/metabolism , Nucleic Acids/metabolism
9.
Proc Natl Acad Sci U S A ; 114(42): E8855-E8864, 2017 10 17.
Article in English | MEDLINE | ID: mdl-28973913

ABSTRACT

We previously created two PER2::LUCIFERASE (PER2::LUC) circadian reporter knockin mice that differ only in the Per2 3'-UTR region: Per2::Luc, which retains the endogenous Per2 3'-UTR and Per2::LucSV, where the endogenous Per2 3'-UTR was replaced by an SV40 late poly(A) signal. To delineate the in vivo functions of Per2 3'-UTR, we analyzed circadian rhythms of Per2::LucSV mice. Interestingly, Per2::LucSV mice displayed more than threefold stronger amplitude in bioluminescence rhythms than Per2::Luc mice, and also exhibited lengthened free-running periods (∼24.0 h), greater phase delays following light pulse, and enhanced temperature compensation relative to Per2::Luc Analysis of the Per2 3'-UTR sequence revealed that miR-24, and to a lesser degree miR-30, suppressed PER2 protein translation, and the reversal of this inhibition in Per2::LucSV augmented PER2::LUC protein level and oscillatory amplitude. Interestingly, Bmal1 mRNA and protein oscillatory amplitude as well as CRY1 protein oscillation were increased in Per2::LucSV mice, suggesting rhythmic overexpression of PER2 enhances expression of Per2 and other core clock genes. Together, these studies provide important mechanistic insights into the regulatory roles of Per2 3'-UTR, miR-24, and PER2 in Per2 expression and core clock function.


Subject(s)
Circadian Rhythm/physiology , MicroRNAs/genetics , Period Circadian Proteins/genetics , 3' Untranslated Regions , Animals , Circadian Clocks/genetics , Gene Expression Regulation , Gene Knock-In Techniques , Luciferases/genetics , Mice, Inbred C57BL , Mice, Transgenic , Period Circadian Proteins/metabolism , Protein Biosynthesis , Temperature
10.
Small ; 13(16)2017 04.
Article in English | MEDLINE | ID: mdl-28196309

ABSTRACT

The effect of serum protein adsorption on the biological fate of Spherical Nucleic Acids (SNAs) is investigated. Through a proteomic analysis, it is shown that G-quadruplexes templated on the surface of a gold nanoparticle in the form of SNAs mediate the formation of a protein corona that is rich in complement proteins relative to SNAs composed of poly-thymine (poly-T) DNA. Cellular uptake studies show that complement receptors on macrophage cells recognize the SNA protein corona, facilitating their internalization, and causing G-rich SNAs to accumulate in the liver and spleen more than poly-T SNAs in vivo. These results support the conclusion that nucleic acid sequence and architecture can mediate nanoparticle-biomolecule interactions and alter their cellular uptake and biodistribution properties and illustrate that nucleic acid sequence is an important parameter in the design of SNA therapeutics.


Subject(s)
Endocytosis , Macrophages/metabolism , Nucleic Acids/metabolism , Protein Corona/metabolism , Animals , Base Sequence , Blood Proteins/metabolism , Cell Line , G-Quadruplexes , Humans , Liver/metabolism , Mice, Inbred C57BL , Receptors, Cell Surface/metabolism , Spleen/metabolism , Tissue Distribution
11.
Sci Transl Med ; 5(209): 209ra152, 2013 Oct 30.
Article in English | MEDLINE | ID: mdl-24174328

ABSTRACT

Glioblastoma multiforme (GBM) is a neurologically debilitating disease that culminates in death 14 to 16 months after diagnosis. An incomplete understanding of how cataloged genetic aberrations promote therapy resistance, combined with ineffective drug delivery to the central nervous system, has rendered GBM incurable. Functional genomics efforts have implicated several oncogenes in GBM pathogenesis but have rarely led to the implementation of targeted therapies. This is partly because many "undruggable" oncogenes cannot be targeted by small molecules or antibodies. We preclinically evaluate an RNA interference (RNAi)-based nanomedicine platform, based on spherical nucleic acid (SNA) nanoparticle conjugates, to neutralize oncogene expression in GBM. SNAs consist of gold nanoparticles covalently functionalized with densely packed, highly oriented small interfering RNA duplexes. In the absence of auxiliary transfection strategies or chemical modifications, SNAs efficiently entered primary and transformed glial cells in vitro. In vivo, the SNAs penetrated the blood-brain barrier and blood-tumor barrier to disseminate throughout xenogeneic glioma explants. SNAs targeting the oncoprotein Bcl2Like12 (Bcl2L12)--an effector caspase and p53 inhibitor overexpressed in GBM relative to normal brain and low-grade astrocytomas--were effective in knocking down endogenous Bcl2L12 mRNA and protein levels, and sensitized glioma cells toward therapy-induced apoptosis by enhancing effector caspase and p53 activity. Further, systemically delivered SNAs reduced Bcl2L12 expression in intracerebral GBM, increased intratumoral apoptosis, and reduced tumor burden and progression in xenografted mice, without adverse side effects. Thus, silencing antiapoptotic signaling using SNAs represents a new approach for systemic RNAi therapy for GBM and possibly other lethal malignancies.


Subject(s)
Brain Neoplasms/therapy , Glioblastoma/therapy , Nanoparticles/chemistry , Nucleic Acids/chemistry , RNA Interference , Animals , Apoptosis , Blood-Brain Barrier/metabolism , Blood-Brain Barrier/pathology , Brain Neoplasms/metabolism , Brain Neoplasms/pathology , Cell Line, Tumor , Down-Regulation , Female , Glioblastoma/metabolism , Glioblastoma/pathology , Humans , Mice , Mice, SCID , Muscle Proteins/metabolism , Nucleic Acids/administration & dosage , Proto-Oncogene Proteins c-bcl-2/metabolism , Tumor Burden , Xenograft Model Antitumor Assays
12.
Chronobiol Int ; 30(4): 540-7, 2013 May.
Article in English | MEDLINE | ID: mdl-23428333

ABSTRACT

We report that the neural representation of the time of day (time memory) in golden hamsters involves the setting of a 24-h oscillator that is functionally and anatomically distinct from the circadian clock in the suprachiasmatic nucleus (SCN), but is entrained by the SCN acting as a weak zeitgeber. In hamsters, peak conditioned place avoidance (CPA) was expressed only near the time of day of the learning experience (± 2 h) for the first days after conditioning. On a 14:10 light:dark cycle, with conditioning at the end of the light period (zeitgeber time 11 [ZT11]), CPA behavior, including time of day memory, was retained for more than 18 d. With conditioning in the early day (zeitgeber time 03 [ZT03]), CPA was completely lost after 5 d but reemerged after an additional 6 d, with the peak avoidance time shifted to ZT11. When the entraining light cycle was shifted immediately following learning at either ZT11 or ZT03, with no additional experience in the training apparatus, peak CPA 18 d later was always found at ZT11 on the shifted light cycles. When conditioned at ZT03, then placed into constant dark for 18 cycles, the peak shifted to subjective circadian time 11 (CT11). In all experiments, the peak CPA time was set initially to the time of experience, and was reset subsequently to the end of the subjective day, without memory loss for other context associations. In the absence of an SCN, peak avoidance was not reset. Therefore, time memory is distinct from other context memories, and involves the setting of a non-SCN circadian oscillator. We suggest that circadian oscillators underlying time memory work in concert with the SCN to enable anticipation of critical conditions according to both immediate- and long-term probabilities of where and when important conditions could be encountered again.


Subject(s)
Circadian Clocks/physiology , Memory/physiology , Time Perception/physiology , Animals , Cricetinae , Male , Photoperiod
13.
Trends Mol Med ; 16(12): 553-60, 2010 Dec.
Article in English | MEDLINE | ID: mdl-21087901

ABSTRACT

Atherosclerosis is the disease mechanism responsible for coronary heart disease (CHD), the leading cause of death worldwide. One strategy to combat atherosclerosis is to increase the amount of circulating high-density lipoproteins (HDL), which transport cholesterol from peripheral tissues to the liver for excretion. The process, known as reverse cholesterol transport, is thought to be one of the main reasons for the significant inverse correlation observed between HDL blood levels and the development of CHD. This article highlights the most common strategies for treating atherosclerosis using HDL. We further detail potential treatment opportunities that utilize nanotechnology to increase the amount of HDL in circulation. The synthesis of biomimetic HDL nanostructures that replicate the chemical and physical properties of natural HDL provides novel materials for investigating the structure-function relationships of HDL and for potential new therapeutics to combat CHD.


Subject(s)
Lipoproteins, HDL/chemical synthesis , Nanotechnology , Animals , Coronary Disease/blood , Coronary Disease/drug therapy , Humans , Lipoproteins, HDL/blood , Lipoproteins, HDL/therapeutic use , Metal Nanoparticles/chemistry
14.
PLoS Biol ; 8(10): e1000513, 2010 Oct 12.
Article in English | MEDLINE | ID: mdl-20967239

ABSTRACT

Bmal1 is an essential transcriptional activator within the mammalian circadian clock. We report here that the suprachiasmatic nucleus (SCN) of Bmal1-null mutant mice, unexpectedly, generates stochastic oscillations with periods that overlap the circadian range. Dissociated SCN neurons expressed fluctuating levels of PER2 detected by bioluminescence imaging but could not generate circadian oscillations intrinsically. Inhibition of intercellular communication or cyclic-AMP signaling in SCN slices, which provide a positive feed-forward signal to drive the intracellular negative feedback loop, abolished the stochastic oscillations. Propagation of this feed-forward signal between SCN neurons then promotes quasi-circadian oscillations that arise as an emergent property of the SCN network. Experimental analysis and mathematical modeling argue that both intercellular coupling and molecular noise are required for the stochastic rhythms, providing a novel biological example of noise-induced oscillations. The emergence of stochastic circadian oscillations from the SCN network in the absence of cell-autonomous circadian oscillatory function highlights a previously unrecognized level of circadian organization.


Subject(s)
Circadian Clocks/physiology , Circadian Rhythm/physiology , Suprachiasmatic Nucleus/physiology , ARNTL Transcription Factors/genetics , ARNTL Transcription Factors/metabolism , Animals , Cell Communication/physiology , Cyclic AMP/metabolism , Mice , Mice, Knockout , Neurons/metabolism , Period Circadian Proteins/genetics , Period Circadian Proteins/metabolism , Stochastic Processes , Suprachiasmatic Nucleus/cytology , Tissue Culture Techniques
15.
Nature ; 466(7306): 627-31, 2010 Jul 29.
Article in English | MEDLINE | ID: mdl-20562852

ABSTRACT

The molecular clock maintains energy constancy by producing circadian oscillations of rate-limiting enzymes involved in tissue metabolism across the day and night. During periods of feeding, pancreatic islets secrete insulin to maintain glucose homeostasis, and although rhythmic control of insulin release is recognized to be dysregulated in humans with diabetes, it is not known how the circadian clock may affect this process. Here we show that pancreatic islets possess self-sustained circadian gene and protein oscillations of the transcription factors CLOCK and BMAL1. The phase of oscillation of islet genes involved in growth, glucose metabolism and insulin signalling is delayed in circadian mutant mice, and both Clock and Bmal1 (also called Arntl) mutants show impaired glucose tolerance, reduced insulin secretion and defects in size and proliferation of pancreatic islets that worsen with age. Clock disruption leads to transcriptome-wide alterations in the expression of islet genes involved in growth, survival and synaptic vesicle assembly. Notably, conditional ablation of the pancreatic clock causes diabetes mellitus due to defective beta-cell function at the very latest stage of stimulus-secretion coupling. These results demonstrate a role for the beta-cell clock in coordinating insulin secretion with the sleep-wake cycle, and reveal that ablation of the pancreatic clock can trigger the onset of diabetes mellitus.


Subject(s)
ARNTL Transcription Factors/genetics , CLOCK Proteins/genetics , Circadian Rhythm/physiology , Diabetes Mellitus/metabolism , Insulin/blood , Islets of Langerhans/metabolism , ARNTL Transcription Factors/deficiency , ARNTL Transcription Factors/metabolism , Aging/genetics , Aging/pathology , Animals , Blood Glucose/analysis , Blood Glucose/metabolism , CLOCK Proteins/deficiency , CLOCK Proteins/metabolism , Cell Proliferation , Cell Size , Cell Survival , Circadian Rhythm/genetics , Diabetes Mellitus/genetics , Gene Expression Profiling , Glucose Intolerance/genetics , Glucose Tolerance Test , In Vitro Techniques , Insulin/metabolism , Insulin Secretion , Islets of Langerhans/pathology , Mice , Period Circadian Proteins/genetics , Period Circadian Proteins/metabolism , Phenotype , Sleep/genetics , Sleep/physiology , Synaptic Vesicles/metabolism , Wakefulness/genetics , Wakefulness/physiology
16.
Nat Rev Genet ; 9(10): 764-75, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18802415

ABSTRACT

Circadian cycles affect a variety of physiological processes, and disruptions of normal circadian biology therefore have the potential to influence a range of disease-related pathways. The genetic basis of circadian rhythms is well studied in model organisms and, more recently, studies of the genetic basis of circadian disorders has confirmed the conservation of key players in circadian biology from invertebrates to humans. In addition, important advances have been made in understanding how these molecules influence physiological functions in tissues throughout the body. Together, these studies set the scene for applying our knowledge of circadian biology to the understanding and treatment of a range of human diseases, including cancer and metabolic and behavioural disorders.


Subject(s)
Chronobiology Disorders/genetics , Circadian Rhythm/genetics , Circadian Rhythm/physiology , Disease/etiology , Animals , Biological Clocks/genetics , Brain/physiology , Chronobiology Disorders/complications , Drug Administration Schedule , Drug Therapy/methods , Feedback, Physiological/genetics , Gene Regulatory Networks/physiology , Humans , Models, Biological , Mood Disorders/etiology , Mood Disorders/genetics , Organ Specificity/genetics
17.
Eur J Neurosci ; 25(11): 3359-66, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17553004

ABSTRACT

Circadian activity rhythms in mammals are controlled by the expression and transcriptional regulation of clock genes in the suprachiasmatic nucleus (SCN). The circadian cycle length in hamsters is regulated in part by casein kinase I epsilon (CKIepsilon). A semidominant mutation (C-->T, R178C, CKIepsilon(tau)) appears to act as a dominant-negative allele to shorten the period of circadian rhythms. We tested this hypothesis in vivo by expressing wild-type CKIepsilon gene in homozygous tau mutant hamsters. High-level CKIepsilon(+/+) gene transfer and expression (as indicated by green fluorescent protein) were obtained by injecting CKIepsilon-containing plasmids bilaterally near the SCN, followed by in vivo electroporation. Rhythmicity reappeared 5-7 days after electroporation, with a gradual increase in circadian period over the next 10 days. The circadian period returned to the baseline over the next 20 days. For the five hamsters with clearest gene expression in the SCN, the mean lengthening time was 39.6 min. Period change was not observed in either control tau mutant hamsters electroporated with plasmids lacking the CKIepsilon gene or in wild-type hamsters with plasmids containing the wild-type CKIepsilon gene. Therefore, normal periodicity in homozygous CKIepsilon(tau) hamsters was partially rescued by expression of the wild-type CKIepsilon gene in the SCN, supporting a competitive and dominant-negative action of the mutant allele. This study shows that electroporation of wild-type CKIepsilon gene into the SCN is sufficient for lengthening the shorter circadian period of tau mutant hamsters in a time-dependent way and supports the conclusion that CKIepsilon(tau) is the cause of the shorter period.


Subject(s)
Casein Kinase 1 epsilon/genetics , Casein Kinase 1 epsilon/metabolism , Circadian Rhythm/genetics , Mutation , Suprachiasmatic Nucleus/physiology , tau Proteins/genetics , Animals , Animals, Genetically Modified , Cricetinae , Electroporation/methods , Male , Time Factors , Transcription, Genetic/physiology
18.
Cell ; 129(3): 605-16, 2007 May 04.
Article in English | MEDLINE | ID: mdl-17482552

ABSTRACT

Molecular mechanisms of the mammalian circadian clock have been studied primarily by genetic perturbation and behavioral analysis. Here, we used bioluminescence imaging to monitor Per2 gene expression in tissues and cells from clock mutant mice. We discovered that Per1 and Cry1 are required for sustained rhythms in peripheral tissues and cells, and in neurons dissociated from the suprachiasmatic nuclei (SCN). Per2 is also required for sustained rhythms, whereas Cry2 and Per3 deficiencies cause only period length defects. However, oscillator network interactions in the SCN can compensate for Per1 or Cry1 deficiency, preserving sustained rhythmicity in mutant SCN slices and behavior. Thus, behavior does not necessarily reflect cell-autonomous clock phenotypes. Our studies reveal previously unappreciated requirements for Per1, Per2, and Cry1 in sustaining cellular circadian rhythmicity and demonstrate that SCN intercellular coupling is essential not only to synchronize component cellular oscillators but also for robustness against genetic perturbations.


Subject(s)
Biological Clocks/physiology , Cell Cycle Proteins/physiology , Circadian Rhythm/physiology , Flavoproteins/physiology , Nuclear Proteins/physiology , Suprachiasmatic Nucleus/physiology , Transcription Factors/physiology , Animals , Cell Cycle Proteins/genetics , Cells, Cultured , Cryptochromes , Fibroblasts , Flavoproteins/genetics , Mice , Motor Activity , Mutation , Neurons/metabolism , Nuclear Proteins/genetics , Period Circadian Proteins , Suprachiasmatic Nucleus/cytology , Transcription Factors/genetics
19.
PLoS Genet ; 3(2): e33, 2007 Feb 23.
Article in English | MEDLINE | ID: mdl-17319750

ABSTRACT

The mechanism of circadian oscillations in mammals is cell autonomous and is generated by a set of genes that form a transcriptional autoregulatory feedback loop. While these "clock genes" are well conserved among animals, their specific functions remain to be fully understood and their roles in central versus peripheral circadian oscillators remain to be defined. We utilized the in vivo inducible tetracycline-controlled transactivator (tTA) system to regulate Clock gene expression conditionally in a tissue-specific and temporally controlled manner. Through the use of Secretogranin II to drive tTA expression, suprachiasmatic nucleus- and brain-directed expression of a tetO::Clock(Delta19) dominant-negative transgene lengthened the period of circadian locomotor rhythms in mice, whereas overexpression of a tetO::Clock(wt) wild-type transgene shortened the period. Low doses (10 mug/ml) of doxycycline (Dox) in the drinking water efficiently inactivated the tTA protein to silence the tetO transgenes and caused the circadian periodicity to return to a wild-type state. Importantly, low, but not high, doses of Dox were completely reversible and led to a rapid reactivation of the tetO transgenes. The rapid time course of tTA-regulated transgene expression demonstrates that the CLOCK protein is an excellent indicator for the kinetics of Dox-dependent induction/repression in the brain. Interestingly, the daily readout of circadian period in this system provides a real-time readout of the tTA transactivation state in vivo. In summary, the tTA system can manipulate circadian clock gene expression in a tissue-specific, conditional, and reversible manner in the central nervous system. The specific methods developed here should have general applicability for the study of brain and behavior in the mouse.


Subject(s)
Behavior, Animal , Brain/metabolism , Circadian Rhythm , Genetic Vectors , Trans-Activators/metabolism , Animals , CLOCK Proteins , Circadian Rhythm/genetics , Doxycycline/pharmacology , Gene Expression Regulation/drug effects , Light , Mice , Mice, Inbred C57BL , Mice, Transgenic , Models, Biological , Molecular Sequence Data , Motor Activity , Trans-Activators/genetics , Transgenes
20.
Science ; 314(5803): 1304-8, 2006 Nov 24.
Article in English | MEDLINE | ID: mdl-17124323

ABSTRACT

The basic helix-loop-helix (bHLH)-Per-Arnt-Sim (PAS) domain transcription factor BMAL1 is an essential component of the mammalian circadian pacemaker. Bmal1-/- mice lose circadian rhythmicity but also display tendon calcification and decreased activity, body weight, and longevity. To investigate whether these diverse functions of BMAL1 are tissue-specific, we produced transgenic mice that constitutively express Bmal1 in brain or muscle and examined the effects of rescued gene expression in Bmal1-/- mice. Circadian rhythms of wheel-running activity were restored in brain-rescued Bmal1-/- mice in a conditional manner; however, activity levels and body weight were lower than those of wild-type mice. In contrast, muscle-rescued Bmal1-/- mice exhibited normal activity levels and body weight yet remained behaviorally arrhythmic. Thus, Bmal1 has distinct tissue-specific functions that regulate integrative physiology.


Subject(s)
Basic Helix-Loop-Helix Transcription Factors/physiology , Brain/metabolism , Circadian Rhythm , Motor Activity , Muscle, Skeletal/metabolism , ARNTL Transcription Factors , Animals , Basic Helix-Loop-Helix Transcription Factors/genetics , Body Weight , Calcinosis , Cell Cycle Proteins/genetics , Chromosomes, Artificial, Bacterial , Gene Expression , Longevity , Mice , Mice, Inbred C57BL , Mice, Transgenic , Nuclear Proteins/genetics , Organ Specificity , Period Circadian Proteins , Suprachiasmatic Nucleus/metabolism , Tendons/pathology , Transcription Factors/genetics
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