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1.
Arch Clin Neuropsychol ; 39(3): 276-289, 2024 Apr 24.
Article in English | MEDLINE | ID: mdl-38520374

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 virus has, up to the time of this article, resulted in >770 million cases of COVID-19 illness worldwide, and approximately 7 million deaths, including >1.1 million in the United States. Although defined as a respiratory virus, early in the pandemic, it became apparent that considerable numbers of people recovering from COVID-19 illness experienced persistence or new onset of multi-system health problems, including neurologic and cognitive and behavioral health concerns. Persistent multi-system health problems are defined as Post-COVID-19 Condition (PCC), Post-Acute Sequelae of COVID-19, or Long COVID. A significant number of those with PCC report cognitive problems. This paper reviews the current state of scientific knowledge on persisting cognitive symptoms in adults following COVID-19 illness. A brief history is provided of the emergence of concerns about persisting cognitive problems following COVID-19 illness and the definition of PCC. Methodologic factors that complicate clear understanding of PCC are reviewed. The review then examines research on patterns of cognitive impairment that have been found, factors that may contribute to increased risk, behavioral health variables, and interventions being used to ameliorate persisting symptoms. Finally, recommendations are made about ways neuropsychologists can improve the quality of existing research.


Subject(s)
Cognitive Dysfunction , Post-Acute COVID-19 Syndrome , Adult , Humans , Cognitive Dysfunction/etiology , COVID-19/complications , SARS-CoV-2 , Post-Acute COVID-19 Syndrome/physiopathology , Neuropsychology
2.
bioRxiv ; 2024 Mar 04.
Article in English | MEDLINE | ID: mdl-38370632

ABSTRACT

Failure of septation of the interventricular septum (IVS) is the most common congenital heart defect (CHD), but mechanisms for patterning the IVS are largely unknown. We show that a Tbx5+/Mef2cAHF+ progenitor lineage forms a compartment boundary bisecting the IVS. This coordinated population originates at a first- and second heart field interface, subsequently forming a morphogenetic nexus. Ablation of Tbx5+/Mef2cAHF+ progenitors cause IVS disorganization, right ventricular hypoplasia and mixing of IVS lineages. Reduced dosage of the CHD transcription factor TBX5 disrupts boundary position and integrity, resulting in ventricular septation defects (VSDs) and patterning defects, including Slit2 and Ntn1 misexpression. Reducing NTN1 dosage partly rescues cardiac defects in Tbx5 mutant embryos. Loss of Slit2 or Ntn1 causes VSDs and perturbed septal lineage distributions. Thus, we identify essential cues that direct progenitors to pattern a compartment boundary for proper cardiac septation, revealing new mechanisms for cardiac birth defects.

3.
Oman J Ophthalmol ; 16(2): 333-335, 2023.
Article in English | MEDLINE | ID: mdl-37602156

ABSTRACT

Familial exudative vitreoretinopathy (FEVR) is a rare genetically heterogeneous inherited disorder with varied presentation. We report a case of FEVR with a classic tractional component and a rare co-occurrence of macular hole with subtotal retinal detachment. The diagnosis was made on clinical examination and imaging. There have been four cases of full-thickness macular holes reported in the literature and none with macular hole retinal detachment. The patient underwent vitrectomy for the same and had silicone oil removal with attached retina postoperatively. We want to highlight this rare association and emphasize the importance of regular follow-up of FEVR cases which tend to progress after remaining quiescent for years.

4.
Genes Dev ; 36(11-12): 652-663, 2022 06 01.
Article in English | MEDLINE | ID: mdl-35835508

ABSTRACT

Congenital heart defects (CHDs) are among the most common birth defects, but their etiology has long been mysterious. In recent decades, the development of a variety of experimental models has led to a greater understanding of the molecular basis of CHDs. In this review, we contrast mouse models of CHD, which maintain the anatomical arrangement of the heart, and human cellular models of CHD, which are more likely to capture human-specific biology but lack anatomical structure. We also discuss the recent development of cardiac organoids, which are a promising step toward more anatomically informative human models of CHD.


Subject(s)
Heart Defects, Congenital , Organoids , Animals , Disease Models, Animal , Heart , Heart Defects, Congenital/genetics , Humans , Mice
5.
BMJ Case Rep ; 15(3)2022 Mar 23.
Article in English | MEDLINE | ID: mdl-35321910

ABSTRACT

A man in his 20s presented to the neurosurgery department 2 years ago with headache and blurred vision. He was diagnosed to have a suprasellar mass on neuroimaging. Best-corrected visual acuity in the right eye was 6/36 and that in the left eye was 6/60. Automated visual fields showed a temporal hemianopia in the right eye and an advanced field defect in the left eye. His hormonal profile was normal, and he underwent partial excision of suprasellar tumour, which was a histopathologically proven paraganglioma (PGL). Subsequently, the patient underwent radiotherapy and his vision and visual fields showed improvement. Follow-up examination 3 years later showed a left retinal capillary hemangioblastoma (RCH), which was treated with green laser photocoagulation, resulting in complete sclerosis. This case is unique because of the extremely rare coexistence of a sellar PGL and RCH, which to our knowledge has not been reported so far.


Subject(s)
Hemangioblastoma , Paraganglioma , Retinal Neoplasms , von Hippel-Lindau Disease , Hemangioblastoma/diagnosis , Humans , Male , Paraganglioma/complications , Paraganglioma/diagnosis , Paraganglioma/surgery , Retina/pathology , Retinal Neoplasms/diagnosis , von Hippel-Lindau Disease/complications
6.
Nature ; 602(7895): 129-134, 2022 02.
Article in English | MEDLINE | ID: mdl-35082446

ABSTRACT

Differentiation proceeds along a continuum of increasingly fate-restricted intermediates, referred to as canalization1,2. Canalization is essential for stabilizing cell fate, but the mechanisms that underlie robust canalization are unclear. Here we show that the BRG1/BRM-associated factor (BAF) chromatin-remodelling complex ATPase gene Brm safeguards cell identity during directed cardiogenesis of mouse embryonic stem cells. Despite the establishment of a well-differentiated precardiac mesoderm, Brm-/- cells predominantly became neural precursors, violating germ layer assignment. Trajectory inference showed a sudden acquisition of a non-mesodermal identity in Brm-/- cells. Mechanistically, the loss of Brm prevented de novo accessibility of primed cardiac enhancers while increasing the expression of neurogenic factor POU3F1, preventing the binding of the neural suppressor REST and shifting the composition of BRG1 complexes. The identity switch caused by the Brm mutation was overcome by increasing BMP4 levels during mesoderm induction. Mathematical modelling supports these observations and demonstrates that Brm deletion affects cell fate trajectory by modifying saddle-node bifurcations2. In the mouse embryo, Brm deletion exacerbated mesoderm-deleted Brg1-mutant phenotypes, severely compromising cardiogenesis, and reveals an in vivo role for Brm. Our results show that Brm is a compensable safeguard of the fidelity of mesoderm chromatin states, and support a model in which developmental canalization is not a rigid irreversible path, but a highly plastic trajectory.


Subject(s)
Cell Differentiation , Cell Lineage , Mesoderm/cytology , Mesoderm/metabolism , Myocytes, Cardiac/cytology , Transcription Factors/metabolism , Animals , Bone Morphogenetic Protein 4/metabolism , Chromatin/genetics , Chromatin/metabolism , Chromatin Assembly and Disassembly , DNA Helicases/metabolism , Embryo, Mammalian , Epigenesis, Genetic , Female , Gene Expression Regulation , Male , Mice , Myocardium/metabolism , Neurogenesis , Neurons/cytology , Neurons/metabolism , Nuclear Proteins/metabolism , Octamer Transcription Factor-6/metabolism , Phenotype , Repressor Proteins/metabolism , Stem Cells/cytology , Time Factors , Transcription Factors/deficiency , Transcription Factors/genetics
7.
Dev Biol ; 478: 1-12, 2021 10.
Article in English | MEDLINE | ID: mdl-34147472

ABSTRACT

Dorsal root ganglion (DRG) neurons are the predominant cell type that innervates the vertebrate skin. They are typically described as pseudounipolar cells that have central and peripheral axons branching from a single root exiting the cell body. The peripheral axon travels within a nerve to the skin, where free sensory endings can emerge and branch into an arbor that receives and integrates information. In some immature vertebrates, DRG neurons are preceded by Rohon-Beard (RB) neurons. While the sensory endings of RB and DRG neurons function like dendrites, we use live imaging in zebrafish to show that they have axonal plus-end-out microtubule polarity at all stages of maturity. Moreover, we show both cell types have central and peripheral axons with plus-end-out polarity. Surprisingly, in DRG neurons these emerge separately from the cell body, and most cells never acquire the signature pseudounipolar morphology. Like another recently characterized cell type that has multiple plus-end-out neurites, ganglion cells in Nematostella, RB and DRG neurons maintain a somatic microtubule organizing center even when mature. In summary, we characterize key cellular and subcellular features of vertebrate sensory neurons as a foundation for understanding their function and maintenance.


Subject(s)
Ganglia, Spinal/ultrastructure , Microtubules/ultrastructure , Sensory Receptor Cells/ultrastructure , Skin/innervation , Animals , Animals, Genetically Modified , Axons/physiology , Axons/ultrastructure , Cell Body/ultrastructure , Cell Polarity , Dendrites/physiology , Drosophila/cytology , Drosophila/growth & development , Ganglia, Spinal/physiology , Microtubule-Organizing Center/ultrastructure , Sea Anemones/cytology , Sea Anemones/growth & development , Sea Anemones/ultrastructure , Sensory Receptor Cells/physiology , Zebrafish
8.
J Adolesc Health ; 69(5): 806-814, 2021 11.
Article in English | MEDLINE | ID: mdl-34059427

ABSTRACT

PURPOSE: The purpose of this study was to assess the association between attention-deficit/hyperactivity disorder (ADHD) medication adherence and adverse health outcomes in older adolescents transitioning to adulthood. METHODS: In a cohort of 17-year-old adolescents with ADHD at Kaiser Permanente Northern California, we assessed medication adherence (medication possession ratio ≥70%) and any medication use and associations with adverse outcomes at 18 and 19 years of age. We conducted bivariate tests of association and multivariable logistic regression models. RESULTS: Adherence declined from 17 to 19 years of age (36.7%-19.1%, p < .001). Non-white race/ethnicity, lower estimated income, and male sex were associated with nonadherence. Model results show nonadherent females experienced several adverse outcomes: Adherence at 18 years of age (referent: nonadherence) was associated with lower odds of pregnancy (adjusted odds ratio [AOR]: .13, 95% confidence interval [CI]: .03-.54). Any use (referent: nonuse) at 18 years of age was associated with lower odds of sexually transmitted infections among females (AOR: .39, 95% CI: .19-.83), pregnancies (AOR: .26, 95% CI: .13-.50), emergency department visits (AOR: .69, 95% CI: .55-.85), and greater odds of injuries (AOR: 1.16, 95% CI: 1.02-1.32). Adherence at 19 years of age was associated with lower odds of pregnancy (AOR: .13, 95% CI: .02-.95). Any use at 19 years of age was associated with lower odds of injury in females (AOR: .77, 95% CI: .60-.99) pregnancy (AOR: .35, 95% CI: .16-.78), and, in both sexes, substance use (AOR: .71, 95% CI: .55-.92). CONCLUSIONS: Late adolescence is associated with decline in ADHD medication use and adherence. ADHD medication adherence and any ADHD medication use is associated with fewer adverse health outcomes, particularly in females.


Subject(s)
Attention Deficit Disorder with Hyperactivity , Sexually Transmitted Diseases , Substance-Related Disorders , Adolescent , Adult , Attention Deficit Disorder with Hyperactivity/drug therapy , Attention Deficit Disorder with Hyperactivity/epidemiology , Cohort Studies , Female , Humans , Male , Medication Adherence , Substance-Related Disorders/epidemiology
9.
Dev Cell ; 56(3): 292-309.e9, 2021 02 08.
Article in English | MEDLINE | ID: mdl-33321106

ABSTRACT

Haploinsufficiency of transcriptional regulators causes human congenital heart disease (CHD); however, the underlying CHD gene regulatory network (GRN) imbalances are unknown. Here, we define transcriptional consequences of reduced dosage of the CHD transcription factor, TBX5, in individual cells during cardiomyocyte differentiation from human induced pluripotent stem cells (iPSCs). We discovered highly sensitive dysregulation of TBX5-dependent pathways-including lineage decisions and genes associated with heart development, cardiomyocyte function, and CHD genetics-in discrete subpopulations of cardiomyocytes. Spatial transcriptomic mapping revealed chamber-restricted expression for many TBX5-sensitive transcripts. GRN analysis indicated that cardiac network stability, including vulnerable CHD-linked nodes, is sensitive to TBX5 dosage. A GRN-predicted genetic interaction between Tbx5 and Mef2c, manifesting as ventricular septation defects, was validated in mice. These results demonstrate exquisite and diverse sensitivity to TBX5 dosage in heterogeneous subsets of iPSC-derived cardiomyocytes and predicts candidate GRNs for human CHDs, with implications for quantitative transcriptional regulation in disease.


Subject(s)
Gene Regulatory Networks , Haploinsufficiency/genetics , Heart Defects, Congenital/genetics , Models, Biological , T-Box Domain Proteins/genetics , Animals , Body Patterning/genetics , Cell Differentiation , Gene Dosage , Heart Ventricles/pathology , Humans , MEF2 Transcription Factors/metabolism , Mice , Mutation/genetics , Myocytes, Cardiac/metabolism , Transcription, Genetic
10.
Development ; 146(23)2019 12 09.
Article in English | MEDLINE | ID: mdl-31784461

ABSTRACT

Long intergenic non-coding RNAs (lincRNAs) have been implicated in gene regulation, but their requirement for development needs empirical interrogation. We computationally identified nine murine lincRNAs that have developmentally regulated transcriptional and epigenomic profiles specific to early heart differentiation. Six of the nine lincRNAs had in vivo expression patterns supporting a potential function in heart development, including a transcript downstream of the cardiac transcription factor Hand2, which we named Handlr (Hand2-associated lincRNA), Rubie and Atcayos We genetically ablated these six lincRNAs in mouse, which suggested genomic regulatory roles for four of the cohort. However, none of the lincRNA deletions led to severe cardiac phenotypes. Thus, we stressed the hearts of adult Handlr and Atcayos mutant mice by transverse aortic banding and found that absence of these lincRNAs did not affect cardiac hypertrophy or left ventricular function post-stress. Our results support roles for lincRNA transcripts and/or transcription in the regulation of topologically associated genes. However, the individual importance of developmentally specific lincRNAs is yet to be established. Their status as either gene-like entities or epigenetic components of the nucleus should be further considered.


Subject(s)
Cell Differentiation , Epigenesis, Genetic , Gene Expression Regulation, Developmental , Heart/embryology , Myocardium/metabolism , RNA, Long Noncoding/biosynthesis , Animals , Gene Deletion , Heart Defects, Congenital/embryology , Heart Defects, Congenital/genetics , Mice , Mice, Mutant Strains , RNA, Long Noncoding/genetics
11.
J Cell Biol ; 218(7): 2309-2328, 2019 07 01.
Article in English | MEDLINE | ID: mdl-31076454

ABSTRACT

Microtubule minus ends are thought to be stable in cells. Surprisingly, in Drosophila and zebrafish neurons, we observed persistent minus end growth, with runs lasting over 10 min. In Drosophila, extended minus end growth depended on Patronin, and Patronin reduction disrupted dendritic minus-end-out polarity. In fly dendrites, microtubule nucleation sites localize at dendrite branch points. Therefore, we hypothesized minus end growth might be particularly important beyond branch points. Distal dendrites have mixed polarity, and reduction of Patronin lowered the number of minus-end-out microtubules. More strikingly, extra Patronin made terminal dendrites almost completely minus-end-out, indicating low Patronin normally limits minus-end-out microtubules. To determine whether minus end growth populated new dendrites with microtubules, we analyzed dendrite development and regeneration. Minus ends extended into growing dendrites in the presence of Patronin. In sum, our data suggest that Patronin facilitates sustained microtubule minus end growth, which is critical for populating dendrites with minus-end-out microtubules.


Subject(s)
Dendrites/genetics , Drosophila Proteins/genetics , Drosophila melanogaster/growth & development , Microtubule-Associated Proteins/genetics , Neurons/metabolism , Animals , Cell Polarity/genetics , Drosophila melanogaster/genetics , Embryo, Nonmammalian , Embryonic Development/genetics , Kinesins/genetics , Microtubules/genetics
12.
BMJ Case Rep ; 20182018 Apr 17.
Article in English | MEDLINE | ID: mdl-29666084

ABSTRACT

A 58-year-old man, a known diabetic and hypertensive for 5 years was presented to us with a drop in reading vision in both eyes of 2 months duration. His best-corrected visual acuity was 6/24, N36 in both eyes. Fundus findings revealed moderate non-proliferative diabetic retinopathy with bilateral diffuse macular oedema. When conventional therapy with intravitreal ranibizumab did not alter the clinical picture, we looked into the differential diagnosis of bilateral persistent macular detachments and investigated further. Haematological tests revealed severe anaemia with pancytopenia, which prompted further investigations including a bone marrow biopsy confirming a diagnosis of multiple myeloma. Chemotherapy gradually caused resolution of the macular detachments at 8 months follow-up. This report illustrates that a high index of suspicion regarding systemic condition is required in certain cases presenting as diabetic macular oedema, but not responding to the conventional treatment.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Cyclophosphamide/therapeutic use , Dexamethasone/therapeutic use , Diabetic Retinopathy/diagnostic imaging , Macular Edema/diagnostic imaging , Multiple Myeloma/diagnostic imaging , Thalidomide/therapeutic use , Vision Disorders/diagnostic imaging , Anemia/diagnosis , Biopsy, Large-Core Needle , Bone Marrow/pathology , Diabetic Retinopathy/complications , Diabetic Retinopathy/physiopathology , Diagnosis, Differential , Fluorescein Angiography , Humans , Macular Edema/pathology , Male , Middle Aged , Multiple Myeloma/diagnosis , Multiple Myeloma/drug therapy , Multiple Myeloma/pathology , Pancytopenia/diagnosis , Tomography, Optical Coherence , Treatment Outcome , Vision Disorders/etiology , Vision Disorders/physiopathology
13.
Neural Dev ; 12(1): 15, 2017 Aug 17.
Article in English | MEDLINE | ID: mdl-28818097

ABSTRACT

BACKGROUND: After axon severing, neurons recover function by reinitiating axon outgrowth. New outgrowth often originates from the remaining axon stump. However, in many mammalian neurons, new axons initiate from a dendritic site when the axon is injured close to the cell body. METHODS: Drosophila sensory neurons are ideal for studying neuronal injury responses because they can be injured reproducibly in a variety of genetic backgrounds. In Drosophila, it has been shown that a complex sensory neuron, ddaC, can regenerate an axon from a stump, and a simple sensory neuron, ddaE, can regenerate an axon from a dendrite. To provide a more complete picture of axon regeneration in these cell types, we performed additional injury types. RESULTS: We found that ddaE neurons can initiate regeneration from an axon stump when a stump remains. We also showed that ddaC neurons regenerate from the dendrite when the axon is severed close to the cell body. We next demonstrated if a stump remains, new axons can originate from this site and a dendrite at the same time. Because cutting the axon close to the cell body results in growth of the new axon from a dendrite, and cutting further out may not, we asked whether the initial response in the cell body was similar after both types of injury. A transcriptional reporter for axon injury signaling, puc-GFP, increased with similar timing and levels after proximal and distal axotomy. However, changes in dendritic microtubule polarity differed in response to the two types of injury, and were influenced by the presence of a scar at the distal axotomy site. CONCLUSIONS: We conclude that both ddaE and ddaC can regenerate axons either from the stump or a dendrite, and that there is some feedback between the two sites that modulates dendritic microtubule polarity.


Subject(s)
Axons/physiology , Dendrites/physiology , Nerve Regeneration/physiology , Animals , Axotomy , Disease Models, Animal , Drosophila , Sensory Receptor Cells/physiology
14.
Mol Biol Cell ; 27(21): 3245-3256, 2016 11 01.
Article in English | MEDLINE | ID: mdl-27605706

ABSTRACT

Mutations in >50 genes, including spastin and atlastin, lead to hereditary spastic paraplegia (HSP). We previously demonstrated that reduction of spastin leads to a deficit in axon regeneration in a Drosophila model. Axon regeneration was similarly impaired in neurons when HSP proteins atlastin, seipin, and spichthyin were reduced. Impaired regeneration was dependent on genetic background and was observed when partial reduction of HSP proteins was combined with expression of dominant-negative microtubule regulators, suggesting that HSP proteins work with microtubules to promote regeneration. Microtubule rearrangements triggered by axon injury were, however, normal in all genotypes. We examined other markers to identify additional changes associated with regeneration. Whereas mitochondria, endosomes, and ribosomes did not exhibit dramatic repatterning during regeneration, the endoplasmic reticulum (ER) was frequently concentrated near the tip of the growing axon. In atlastin RNAi and spastin mutant animals, ER accumulation near single growing axon tips was impaired. ER tip concentration was observed only during axon regeneration and not during dendrite regeneration. In addition, dendrite regeneration was unaffected by reduction of spastin or atlastin. We propose that the HSP proteins spastin and atlastin promote axon regeneration by coordinating concentration of the ER and microtubules at the growing axon tip.


Subject(s)
Adenosine Triphosphatases/metabolism , Axons/metabolism , Drosophila Proteins/metabolism , GTP Phosphohydrolases/metabolism , Regeneration/physiology , Adenosine Triphosphatases/genetics , Animals , Axons/physiology , Dendrites/metabolism , Dendrites/physiology , Drosophila/metabolism , Drosophila Proteins/genetics , Endoplasmic Reticulum/metabolism , Endoplasmic Reticulum/physiology , GTP Phosphohydrolases/genetics , Membrane Proteins/metabolism , Microtubules , Mitochondria/metabolism , Mutation , Neurogenesis/genetics , Neurogenesis/physiology , RNA Interference , Spastic Paraplegia, Hereditary/genetics , Spastic Paraplegia, Hereditary/metabolism
15.
J Am Soc Cytopathol ; 4(3): 160-169, 2015.
Article in English | MEDLINE | ID: mdl-31051697

ABSTRACT

INTRODUCTION: Cytologic rapid on-site evaluation (ROSE) during minimally invasive biopsy procedures is an increasingly important service provided by cytopathology to increase diagnostic yield and appropriately triage cellular material. Although ROSE can be performed by cytopathologists, cytotechnologists, or cytopathology fellows, few studies have directly compared both procedural and diagnostic outcome measures among different ROSE personnel. MATERIALS AND METHODS: We evaluated all transthoracic computed tomography (CT)-guided lung biopsies in which ROSE was performed during a 1-year period at 2 academic institutions with similar patient populations and procedural methods: Dartmouth-Hitchcock Medical Center (DHMC) (where ROSE is performed by cytopathologists) and the Beth Israel Deaconess Medical Center (BIDMC) (where ROSE is rendered by either cytotechnologists or cytopathology fellows). RESULTS: A total of 273 CT-guided transthoracic lung biopsies (190 DHMC, 83 BIDMC) were analyzed. There was no major difference in procedure time with respect to ROSE personnel. The repeat procedure rate for nondiagnostic biopsies was similar at DHMC (cytopathologists) and BIDMC (cytotechnologists or cytology fellows) (2.1% versus 2.3%, P = 1.0). Adequacy rates for cytopathologists, cytotechnologists, and cytopathology fellows were comparable (P = 0.23). ROSE assessments by cytopathologists were more concordant with the final diagnosis (87%) than those by cytotechnologists (82%) or cytopathology fellows (79%); this difference was not statistically significant (P = 0.28). CONCLUSIONS: ROSE procedural and diagnostic outcomes for transthoracic CT-guided lung biopsies were similar among cytopathologists, cytotechnologists, and cytopathology fellows.

16.
Blood ; 122(15): 2572-81, 2013 Oct 10.
Article in English | MEDLINE | ID: mdl-23990620

ABSTRACT

The Ikaros gene (Ikzf1) encodes a family of zinc-finger transcription factors implicated in hematopoietic cell differentiation. Here we show that Ikaros suppresses the development of basophils, which are proinflammatory cells of the myeloid lineage. In the absence of extrinsic basophil-inducing signals, Ikaros(-/-) (Ik(-/-)) mice exhibit increases in basophil numbers in blood and bone marrow and in their direct precursors in bone marrow and the spleen, as well as decreased numbers of intestinal mast cells. In vitro culture of Ik(-/-) bone marrow under mast cell differentiation conditions also results in predominance of basophils. Basophil expansion is associated with an increase in basophil progenitors, increased expression of Cebpa and decreased expression of mast cell-specifying genes Hes1 and microphthalmia-associated transcription factor (Mitf). Ikaros directly associates with regulatory sites within Cebpa and Hes1 and regulates the acquisition of permissive H3K4 tri-methylation marks at the Cebpa locus and reduces H3K4 tri-methylation at the Hes1 promoter. Ikaros blockade in cultured cells or transfer of Ik(-/-) bone marrow into irradiated Ik(+/+) recipients also results in increased basophils confirming a cell-intrinsic effect of Ikaros on basophil development. We conclude that Ikaros is a suppressor of basophil differentiation under steady-state conditions and that it acts by regulating permissive chromatin modifications of Cebpa.


Subject(s)
Basophils/cytology , Basophils/physiology , CCAAT-Enhancer-Binding Proteins/genetics , Ikaros Transcription Factor/genetics , Animals , Basic Helix-Loop-Helix Transcription Factors/genetics , Basic Helix-Loop-Helix Transcription Factors/physiology , Bone Marrow Cells/cytology , Bone Marrow Cells/physiology , CCAAT-Enhancer-Binding Proteins/physiology , Cell Differentiation/genetics , Cell Lineage/genetics , Cells, Cultured , Epigenesis, Genetic/genetics , Female , Homeodomain Proteins/genetics , Homeodomain Proteins/physiology , Ikaros Transcription Factor/physiology , Male , Mast Cells/cytology , Mast Cells/physiology , Mice , Mice, 129 Strain , Mice, Inbred C57BL , Mice, Knockout , Transcription Factor HES-1
17.
J Int Assoc Provid AIDS Care ; 12(3): 178-84, 2013.
Article in English | MEDLINE | ID: mdl-23442561

ABSTRACT

Nonengagement in HIV care is a major clinical and public health challenge. To identify the risk factors and reasons, we performed (1) a retrospective study of patients admitted to the hospital with advanced HIV disease, (2) a prospective qualitative study, and (3) a population-based area-wide telephone interview. In the retrospective study, clinic care engagement was associated with age (43.9 ± 9.1 years vs 37.9 ± 7.2 years, P = .005) and improved from 23% to 44% (P = .03) after hospitalization. Survival was higher (93% vs 73%, P = .03) among those who engaged in care. Twelve inpatients were interviewed in the qualitative study. Themes identified for nonengagement were social stigma, indifference, or lack of understanding of care needs/denial and life care issues. In the population-based study, 145 patients were interviewed. In all, 49 denied the need for HIV care and 28 denied their HIV status. Stigma, denial, and indifference or lack of understanding of need are significant barriers to care engagement.


Subject(s)
HIV Infections/psychology , HIV Infections/therapy , Health Knowledge, Attitudes, Practice , Patient Compliance , Patient Participation , Adult , Female , HIV Infections/mortality , Health Services Accessibility , Hospitalization , Humans , Male , Middle Aged , Prospective Studies , Qualitative Research , Retrospective Studies , Social Stigma , Socioeconomic Factors
18.
Cell Rep ; 2(5): 1340-50, 2012 Nov 29.
Article in English | MEDLINE | ID: mdl-23122959

ABSTRACT

Axon regeneration allows neurons to repair circuits after trauma; however, most of the molecular players in this process remain to be identified. Given that microtubule rearrangements have been observed in injured neurons, we tested whether microtubule-severing proteins might play a role in axon regeneration. We found that axon regeneration is extremely sensitive to levels of the microtubule-severing protein spastin. Although microtubule behavior in uninjured neurons was not perturbed in animals heterozygous for a spastin null allele, axon regeneration was severely disrupted in this background. Two types of axon regeneration-regeneration of an axon from a dendrite after proximal axotomy and regeneration of an axon from the stump after distal axotomy-were defective in Drosophila with one mutant copy of the spastin gene. Other types of axon and dendrite outgrowth, including regrowth of dendrites after pruning, were normal in heterozygotes. We conclude that regenerative axon growth is uniquely sensitive to spastin gene dosage.


Subject(s)
Adenosine Triphosphatases/genetics , Axons/metabolism , Drosophila Proteins/genetics , Nerve Regeneration/physiology , Adenosine Triphosphatases/antagonists & inhibitors , Adenosine Triphosphatases/metabolism , Alleles , Animals , Dendrites/metabolism , Drosophila/metabolism , Drosophila Proteins/antagonists & inhibitors , Drosophila Proteins/metabolism , Gene Dosage , Katanin , Microtubules/metabolism , Mutation , RNA Interference , RNA, Small Interfering/metabolism , Tubulin/chemistry , Tubulin/genetics , Tubulin/metabolism
19.
Virology ; 432(1): 10-9, 2012 Oct 10.
Article in English | MEDLINE | ID: mdl-22727833

ABSTRACT

Sequences necessary for activity of the Spinach curly top virus virion sense promoter have been identified within an 84 bp region upstream of two transcription start sites located at nt 252 and 292. RNAs initiating at these sites are expressed at equivalent levels in SCTV-infected Arabidopsis and from promoter-reporter constructs. The promoter is capable of directing expression of all three virion sense genes, although not to the same degree. While CP and V3 expression are similar, expression of V2 is elevated. The promoter is active in transient leaf infusion assays in the absence of C2. In Nicotiana benthamiana plants the promoter is active in vascular tissue and under no conditions did we detect promoter activity in the mesophyll. This is in contrast to begomoviruses where the virion sense promoter is dependent on AL2, a positional homolog of C2, and the promoter is functional in both vascular and mesophyll tissue.


Subject(s)
Geminiviridae/genetics , Gene Expression Regulation, Viral , Promoter Regions, Genetic , Transcription, Genetic , Viral Proteins/biosynthesis , Geminiviridae/physiology , Nicotiana/virology , Transcription Initiation Site
20.
PLoS One ; 7(3): e34172, 2012.
Article in English | MEDLINE | ID: mdl-22479554

ABSTRACT

Nuclear factor of activated T cells (NFAT) plays a critical role in the development and function of immune and non-immune cells. Although NFAT is a central transcriptional regulator of T cell cytokines, its role in macrophage specific gene expression is less defined. Previous work from our group demonstrated that NFAT regulates Il12b gene expression in macrophages. Here, we further investigate NFAT function in murine macrophages and determined the effects of a cell permeable NFAT inhibitor peptide 11R-VIVIT on experimental colitis in mice. Treatment of bone marrow derived macrophages (BMDMs) with tacrolimus or 11R-VIVIT significantly inhibited LPS and LPS plus IFN-γ induced IL-12 p40 mRNA and protein expression. IL-12 p70 and IL-23 secretion were also decreased. NFAT nuclear translocation and binding to the IL-12 p40 promoter was reduced by NFAT inhibition. Experiments in BMDMs from IL-10 deficient (Il10(-/-)) mice demonstrate that inhibition of IL-12 expression by 11R-VIVIT was independent of IL-10 expression. To test its therapeutic potential, 11R-VIVIT was administered systemically to Il10(-/-) mice with piroxicam-induced colitis. 11R-VIVIT treated mice demonstrated significant improvement in colitis compared to mice treated with an inactive peptide. Moreover, decreased spontaneous secretion of IL-12 p40 and TNF in supernatants from colon explant cultures was demonstrated. In summary, NFAT, widely recognized for its role in T cell biology, also regulates important innate inflammatory pathways in macrophages. Selective blocking of NFAT via a cell permeable inhibitory peptide is a promising therapeutic strategy for the treatment of inflammatory bowel diseases.


Subject(s)
Colitis/metabolism , Cytokines/biosynthesis , Macrophages/metabolism , NFATC Transcription Factors/antagonists & inhibitors , NFATC Transcription Factors/metabolism , Active Transport, Cell Nucleus , Animals , Bone Marrow Cells/cytology , Colitis/therapy , Disease Models, Animal , Green Fluorescent Proteins/metabolism , Inflammation , Interferon-gamma/metabolism , Interleukin-10/genetics , Interleukin-12 Subunit p40/metabolism , Lipopolysaccharides/metabolism , Macrophages/cytology , Mice , Mice, Inbred C57BL , Mice, Transgenic , Microscopy, Fluorescence/methods , Nitric Oxide Synthase Type II/genetics , Promoter Regions, Genetic , RNA, Messenger/metabolism , Tacrolimus/pharmacology
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