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3.
Skeletal Radiol ; 53(8): 1573-1582, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38430274

ABSTRACT

OBJECTIVE: To assess the clinical impact of diagnostic musculoskeletal (MSK) injections on treatment decision-making in adolescent and adult patients at a children's hospital. MATERIALS AND METHODS: Retrospective study in patients who underwent diagnostic MSK injections by fluoroscopy or ultrasound (US) between 8/2020 and 3/2023 at a children's hospital. Patients received ropivacaine and triamcinolone acetonide at pain site, reporting quantitative FACES pain score prior to, immediately following, and 2-3 days following injection. Impact on patient care was subsequently assessed. RESULTS: A total of 109 diagnostic fluoroscopic or US MSK injection referrals (mean: 17.6 years old) were included, most commonly hip (76.2%), ankle (9.2%), and iliopsoas tendon sheath (8.3%). Pain improvement occurred in 89.0% immediately and 67.9% 2-3 days after MSK injection, with net 84.4% exhibiting improvement based on pain scores and clinical exams. When there was pain improvement at the site of injection, there was a statistically higher incidence of operative intervention or additional therapeutic injections compared with the cohort that did not have symptom improvement (88% versus 35.3%, P < 0.0001). For the 15.6% (N = 17) of referrals that did not have pain improvement, 17.6% (n = 3) ultimately had an operative intervention at a separate site from the diagnostic injection, as an alternative etiology for the pain was found. CONCLUSION: Image-guided MSK injections play an important role in the management of musculoskeletal disorders. 84.4% of referrals experienced symptom relief, improving confidence for treatment decision-making. Importantly, 15.6% of patients were found to have an alternative etiology for symptoms, altering management altogether.


Subject(s)
Anesthetics, Local , Hospitals, Pediatric , Musculoskeletal Pain , Pain Measurement , Ultrasonography, Interventional , Humans , Adolescent , Female , Male , Musculoskeletal Pain/drug therapy , Musculoskeletal Pain/diagnostic imaging , Retrospective Studies , Ultrasonography, Interventional/methods , Anesthetics, Local/administration & dosage , Adult , Fluoroscopy , Ropivacaine/administration & dosage , Triamcinolone Acetonide/administration & dosage , Child , Radiography, Interventional/methods
4.
Radiographics ; 44(3): e230109, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38358937

ABSTRACT

Biliary abnormalities in children are uncommon, and the spectrum of biliary disorders is broader than in adult patients. Unlike in adults, biliary disorders in children are rarely neoplastic and are more commonly rhabdomyosarcoma rather than cholangiocarcinoma. Pediatric biliary disorders may be embryologic or congenital, such as anatomic gallbladder anomalies, anomalous pancreaticobiliary tracts, various cholestatic processes, congenital cystic lesions, or genetic conditions. They may also be benign, such as biliary filling anomalies, biliary motility disorders, and biliary inflammatory and infectious disorders. Distinguishing these entities with a single imaging modality is challenging. US is the primary imaging modality for initial evaluation of biliary abnormalities in children, due to its wide availability, lack of ionizing radiation, and low cost and because it requires no sedation. Other examinations such as MRI, CT, and nuclear medicine examinations may provide anatomic and functional information to narrow the diagnosis further. Hepatobiliary-specific contrast material with MRI can provide better assessment of biliary anatomy on delayed images than can traditional MRI contrast material. MR cholangiopancreatography (MRCP) allows visualization of the intra- and extrahepatic biliary ducts, which may not be possible with endoscopic retrograde cholangiopancreatography (ERCP). Suspected biliary atresia requires multiple modalities for diagnosis and timely treatment. Determining the type of choledochal cyst calls for a combination of initial US and MRCP. Many benign and malignant biliary masses require biopsy for definitive diagnosis. Knowledge of the imaging appearances of different pediatric biliary abnormalities is necessary for appropriate imaging workup, providing a diagnosis or differential diagnosis, and guiding appropriate management. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.


Subject(s)
Bile Duct Neoplasms , Choledochal Cyst , Gallbladder Diseases , Adult , Humans , Child , Contrast Media , Cholangiopancreatography, Endoscopic Retrograde , Choledochal Cyst/diagnosis , Choledochal Cyst/pathology , Magnetic Resonance Imaging/methods , Bile Ducts, Intrahepatic/pathology , Bile Duct Neoplasms/pathology
8.
Elife ; 112022 10 10.
Article in English | MEDLINE | ID: mdl-36214448

ABSTRACT

Lung development is precisely controlled by underlying gene regulatory networks (GRN). Disruption of genes in the network can interrupt normal development and cause diseases such as bronchopulmonary dysplasia (BPD) - a chronic lung disease in preterm infants with morbid and sometimes lethal consequences characterized by lung immaturity and reduced alveolarization. Here, we generated a transgenic mouse exhibiting a moderate severity BPD phenotype by blocking IGF1 signaling in secondary crest myofibroblasts (SCMF) at the onset of alveologenesis. Using approaches mirroring the construction of the model GRN in sea urchin's development, we constructed the IGF1 signaling network underlying alveologenesis using this mouse model that phenocopies BPD. The constructed GRN, consisting of 43 genes, provides a bird's eye view of how the genes downstream of IGF1 are regulatorily connected. The GRN also reveals a mechanistic interpretation of how the effects of IGF1 signaling are transduced within SCMF from its specification genes to its effector genes and then from SCMF to its neighboring alveolar epithelial cells with WNT5A and FGF10 signaling as the bridge. Consistently, blocking WNT5A signaling in mice phenocopies BPD as inferred by the network. A comparative study on human samples suggests that a GRN of similar components and wiring underlies human BPD. Our network view of alveologenesis is transforming our perspective to understand and treat BPD. This new perspective calls for the construction of the full signaling GRN underlying alveologenesis, upon which targeted therapies for this neonatal chronic lung disease can be viably developed.


Subject(s)
Bronchopulmonary Dysplasia , Infant , Humans , Mice , Infant, Newborn , Animals , Bronchopulmonary Dysplasia/genetics , Gene Regulatory Networks , Infant, Premature , Organogenesis , Disease Models, Animal , Lung , Animals, Newborn , Insulin-Like Growth Factor I/genetics
9.
iScience ; 25(2): 103780, 2022 Feb 18.
Article in English | MEDLINE | ID: mdl-35169685

ABSTRACT

Many acute and chronic diseases affect the distal lung alveoli. Alveolar epithelial cell (AEC) lines are needed to better model these diseases. We used de-identified human remnant transplant lungs to develop a method to establish AEC lines. The lines grow well in 2-dimensional (2D) culture as epithelial monolayers expressing lung progenitor markers. In 3-dimensional (3D) culture with fibroblasts, Matrigel, and specific media conditions, the cells form alveolar-like organoids expressing mature AEC markers including aquaporin 5 (AQP5), G-protein-coupled receptor class C group 5 member A (GPRC5A), and surface marker HTII280. Single-cell RNA sequencing of an AEC line in 2D versus 3D culture revealed increased cellular heterogeneity and induction of cytokine and lipoprotein signaling in 3D organoids. Our approach yields lung progenitor lines that retain the ability to differentiate along the alveolar cell lineage despite long-term expansion and provides a valuable system to model and study the distal lung in vitro.

10.
Eur J Ophthalmol ; 32(3): 1538-1546, 2022 May.
Article in English | MEDLINE | ID: mdl-34041935

ABSTRACT

PURPOSE: To determine the efficacy of an educational intervention on patient adoption and attitudes toward selective laser trabeculoplasty (SLT) as first-line treatment for glaucoma. METHODS: This study is a randomized controlled trial. Subjects include 33 patients within 1-year diagnosis of either primary open-angle glaucoma, ocular hypertension, or pseudoexfoliation syndrome. After informed consent, subjects were randomly assigned to a Usual Care or Educational Intervention group. All subjects completed a pre-intervention questionnaire. The Educational Intervention group was shown a slideshow presentation and a 3-min video and given a post-intervention questionnaire. Follow-up examinations were reviewed for 6 months to determine subject completion of SLT, the primary outcome. Secondary outcomes include assessment of attitude toward SLT before and after intervention. RESULTS: Age, gender, and baseline characteristics between the groups did not differ. The Usual Care group had a higher proportion of African Americans (77% vs 31%, p = 0.04). At 6 months following the intervention, 63% of subjects underwent SLT compared to 35% of Usual Care subjects (p = 0.12). Older age was associated with decreased SLT uptake (OR 0.90, 95% CI 0.82-0.99, p = 0.03). Prior to the intervention, there were no differences in attitudes of both groups regarding SLT therapy. Nineteen percent of Educational Intervention subjects changed positively toward SLT (p = 0.08) and 50% scheduled an SLT appointment after intervention (p = 0.005). CONCLUSIONS: A slideshow and video-based educational intervention may positively enhance patient adoption of SLT.Clinical trial registration name, number, URL: Educational Intervention to Adopt SLT as First-Line Glaucoma Treatment, NCT03365778, https://clinicaltrials.gov/ct2/show/NCT03365778.


Subject(s)
Glaucoma, Open-Angle , Glaucoma , Laser Therapy , Trabeculectomy , Glaucoma/surgery , Glaucoma, Open-Angle/surgery , Humans , Intraocular Pressure , Lasers , Treatment Outcome
11.
Age Ageing ; 50(5): 1600-1606, 2021 09 11.
Article in English | MEDLINE | ID: mdl-34036308

ABSTRACT

BACKGROUND: Deprescribing may benefit older frail patients experiencing polypharmacy. We investigated the scope for deprescribing in acutely hospitalised patients and the long-term implications of continuation of medications that could potentially be deprescribed. METHODS: Acutely hospitalised patients (n = 170) discharged to Residential Aged Care Facilities, ≥75 years and receiving ≥5 regular medications were assessed during admission to determine eligibility for deprescribing of key drug classes, along with the actual incidence of deprescribing. The impact of continuation of nominated drug classes (anticoagulants, antidiabetics, antiplatelets, antipsychotics, benzodiazepines, proton pump inhibitors (PPIs), statins) on a combined endpoint (death/readmission) was determined. RESULTS: Hyperpolypharmacy (>10 regular medications) was common (49.4%) at admission. Varying rates of deprescribing occurred during hospitalisation for the nominated drug classes (8-53%), with considerable potential for further deprescribing (34-90%). PPI use was prevalent (56%) and 89.5% of these had no clear indication. Of the drug classes studied, only continued PPI use at discharge was associated with increased mortality/readmission at 1 year (hazard ratio 1.54, 95% confidence interval (1.06-2.26), P = 0.025), driven largely by readmission. CONCLUSION: There is considerable scope for acute hospitalisation to act as a triage point for deprescribing in older patients. PPIs in particular appeared overprescribed in this susceptible patient group, and this was associated with earlier readmission. Polypharmacy in older hospitalised patients should be targeted for possible deprescribing during hospitalisation, especially PPIs.


Subject(s)
Deprescriptions , Patient Discharge , Aged , Hospitals , Humans , Polypharmacy , Triage
12.
J Glaucoma ; 29(10): 851-856, 2020 10.
Article in English | MEDLINE | ID: mdl-32740509

ABSTRACT

PRECIS: Targeted educational interventions for physicians may be useful in increasing adoption of selective laser trabeculoplasty (SLT) as first line therapy for the treatment of glaucoma. PURPOSE: SLT is a safe and effective first line treatment for glaucoma, however, it is underutilized. To evaluate barriers for the widespread adoption of this procedure, we assessed the beliefs and attitudes of ophthalmologists. We developed an educational intervention directed to physicians to increase the consideration of SLT earlier in the glaucoma treatment paradigm. SUBJECTS AND METHODS: In this prospective study, an online survey and educational slide presentation was sent to a group of comprehensive ophthalmologists, ophthalmology residents, and glaucoma specialists. Subjects were asked to respond to questions regarding their beliefs and attitudes towards SLT before and after watching the educational slide presentation. RESULTS: A total of 53 subjects were enrolled. Before watching the slide presentation, 85% of subjects stated they offer SLT to newly diagnosed patients, although only 28% preferred it over medications. While 52% of physicians reported between 0% and 10% of their newly diagnosed patients receive laser therapy, 47% said they would use it as a first line therapy for all or most newly diagnosed glaucoma patients. Most subjects (94%) stated the educational slide presentation convinced them that SLT is appropriate as a first line therapy for treatment of open angle glaucoma. CONCLUSIONS: A better understanding of the barriers for utilizing SLT as a first line therapy provides valuable information to help increase the adoption of this safe and effective procedure. A targeted educational intervention may improve acceptance of SLT as first line therapy for open angle glaucoma.


Subject(s)
Glaucoma, Open-Angle/surgery , Health Knowledge, Attitudes, Practice , Laser Therapy/methods , Lasers, Solid-State/therapeutic use , Ophthalmologists/psychology , Trabeculectomy/methods , Attitude of Health Personnel , Female , Glaucoma, Open-Angle/physiopathology , Health Surveys , Humans , Intraocular Pressure/physiology , Male , Middle Aged , Prospective Studies , Surveys and Questionnaires , Treatment Outcome
13.
Article in English | MEDLINE | ID: mdl-32337387

ABSTRACT

Lizards are the closest relatives of mammals capable of tail regeneration, but the specific determinants of amniote regenerative capabilities are currently unknown. Macrophages are phagocytic immune cells that play a critical role in wound healing and tissue regeneration in a wide range of species. We hypothesize that macrophages regulate the process of lizard tail regeneration, and that comparisons with mammalian cell populations will yield insight into the role phagocytes play in determining an organism's regenerative potential. Single cell RNA sequencing (scRNAseq) was used to profile lizard immune cells and compare with mouse counterparts to contrast cell types between the two species. Treatment with clodronate liposomes effectively inhibited lizard tail stump tissue ablation and subsequent regeneration, and scRNAseq was used to profile changes in lizard immune cell populations resulting from tail amputation as well as identifying specific cell types affected by clodronate treatment. ScRNAseq analysis of lizard bone marrow, peripheral blood, and tissue-resident phagocyte cell populations was used to trace marker progression during macrophage differentiation and activation. These results indicated that lizard macrophages are recruited to tail amputation injuries faster than mouse populations and express high levels of matrix metalloproteinases (MMPs). In turn, treatment with MMP inhibitors inhibited lizard tail regeneration. These results provide single cell sequencing data sets for evaluating and comparing lizard and mammalian immune cell populations, and identifying macrophage populations that are critical regulators of lizard tail regrowth.

14.
J AAPOS ; 22(4): 309.e1-309.e7, 2018 08.
Article in English | MEDLINE | ID: mdl-30012459

ABSTRACT

PURPOSE: To investigate the prevalence of decreased visual acuity and uncorrected refractive error in school-aged children participating in summer programs. METHODS: During the summers of 2014-2016, Wills Eye Hospital collaborated with summer programs in Philadelphia to provide vision screenings for underserved children. Parental consent was obtained prior to vision screening. Fail criteria included children in grades K-1 (ages 5-6) with visual acuity worse than 20/40 in either eye, children in grades 2-6 (ages 7-13) with visual acuity worse than 20/30 in either eye, or children with ≥2 lines of interocular difference. If decreased visual acuity was correctable to ≥20/30 by the onsite optometrist, two pairs of free eyeglasses were provided. Children with other ocular abnormalities were referred to pediatric ophthalmology. RESULTS: Of 1,627 children screened, 360 children (22.1%) did not pass vision screening, and 64 (3.9%) were referred. The prevalence of decreased distance visual was 34.1%. Younger children were more likely to have worse visual acuity than older children (OR = 0.943; P = 0.023; 95% CI, 0.896-0.992). Myopia (73%), astigmatism (56.8%), hyperopia (15.5%), spherical anisometropia (12.5%), and cylindrical anisometropia (11.9%) presented in the 303 children who underwent a manifest refraction. Myopia increased with age (OR = 0.818; P = 0.001; 95% CI, 0.724-0.922), whereas astigmatism decreased (OR = 0.817; P < 0.001; 95% CI, 0.728-0.913) with age. Two pairs of glasses were provided to 301 children. CONCLUSIONS: Partnership with summer programs and other community initiatives to provide vision screenings facilitates access to eye care ultimately aimed at improving social functioning and academic performance.


Subject(s)
Pediatrics/organization & administration , Refractive Errors/diagnosis , Vision Screening/organization & administration , Adolescent , Child , Child, Preschool , Delivery of Health Care/organization & administration , Female , Humans , Male , Philadelphia
15.
JCI Insight ; 3(11)2018 06 07.
Article in English | MEDLINE | ID: mdl-29875320

ABSTRACT

Oncogenic Kras expression specifically in hematopoietic stem cells (HSCs) induces a rapidly fatal myeloproliferative neoplasm in mice, suggesting that Kras signaling plays a dominant role in normal hematopoiesis. However, such a conclusion is based on expression of an oncogenic version of Kras. Hence, we sought to determine the effect of simply increasing the amount of endogenous wild-type Kras on HSC fate. To this end, we utilized a codon-optimized version of the murine Kras gene (Krasex3op) that we developed, in which silent mutations in exon 3 render the encoded mRNA more efficiently translated, leading to increased protein expression without disruption to the normal gene architecture. We found that Kras protein levels were significantly increased in bone marrow (BM) HSCs in Krasex3op/ex3op mice, demonstrating that the translation of Kras in HSCs is normally constrained by rare codons. Krasex3op/ex3op mice displayed expansion of BM HSCs, progenitor cells, and B lymphocytes, but no evidence of myeloproliferative disease or leukemia in mice followed for 12 months. BM HSCs from Krasex3op/ex3op mice demonstrated increased multilineage repopulating capacity in primary competitive transplantation assays, but secondary competitive transplants revealed exhaustion of long-term HSCs. Following total body irradiation, Krasex3op/ex3op mice displayed accelerated hematologic recovery and increased survival. Mechanistically, HSCs from Krasex3op/ex3op mice demonstrated increased proliferation at baseline, with a corresponding increase in Erk1/2 phosphorylation and cyclin-dependent kinase 4 and 6 (Cdk4/6) activation. Furthermore, both the enhanced colony-forming capacity and in vivo repopulating capacity of HSCs from Krasex3op/ex3op mice were dependent on Cdk4/6 activation. Finally, BM transplantation studies revealed that augmented Kras expression produced expansion of HSCs, progenitor cells, and B cells in a hematopoietic cell-autonomous manner, independent from effects on the BM microenvironment. This study provides fundamental demonstration of codon usage in a mammal having a biological consequence, which may speak to the importance of codon usage in mammalian biology.


Subject(s)
Hematopoiesis/genetics , Hematopoietic Stem Cells/metabolism , Proto-Oncogene Proteins p21(ras)/genetics , Animals , Bone Marrow Transplantation , Cells, Cultured , Codon/genetics , Exons/genetics , Female , Male , Mice , Mice, Transgenic , Models, Animal , Mutation , Primary Cell Culture , Proto-Oncogene Proteins p21(ras)/metabolism , Transplantation Chimera , Whole-Body Irradiation
16.
J Bronchology Interv Pulmonol ; 24(4): 330-333, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28590275

ABSTRACT

Surgical treatment with lung resection has traditionally been the treatment of choice for pulmonary cavities containing aspergillomas that cause hemoptysis. Endobronchial ultrasound (EBUS) is a minimally invasive bronchoscopic technique that is commonly used for transbronchial needle aspiration of hilar and mediastinal lymph nodes as well as centrally located parenchymal lesions. Here, we describe a case of a 71-year-old woman who was found to have a cavitary lesion in the lung containing aspergillomas. Under direct ultrasound visualization with EBUS, liposomal amphotericin B was injected into the aspergillomas. These aspergillomas regressed after treatment. To our knowledge, this is the first reported treatment of aspergilloma with EBUS-guided transbronchial needle injection of liposomal amphotericin B.


Subject(s)
Amphotericin B/administration & dosage , Endoscopic Ultrasound-Guided Fine Needle Aspiration/methods , Pulmonary Aspergillosis/drug therapy , Ultrasonography/methods , Aged , Amphotericin B/therapeutic use , Antifungal Agents/therapeutic use , Female , Humans , Lung/pathology , Pneumonectomy/standards , Pneumonectomy/statistics & numerical data , Pulmonary Aspergillosis/diagnostic imaging , Pulmonary Aspergillosis/pathology , Tomography, X-Ray Computed/methods , Treatment Outcome
17.
Nat Med ; 23(1): 91-99, 2017 01.
Article in English | MEDLINE | ID: mdl-27918563

ABSTRACT

The role of osteolineage cells in regulating hematopoietic stem cell (HSC) regeneration following myelosuppression is not well understood. Here we show that deletion of the pro-apoptotic genes Bak and Bax in osterix (Osx, also known as Sp7 transcription factor 7)-expressing cells in mice promotes HSC regeneration and hematopoietic radioprotection following total body irradiation. These mice showed increased bone marrow (BM) levels of the protein dickkopf-1 (Dkk1), which was produced in Osx-expressing BM cells. Treatment of irradiated HSCs with Dkk1 in vitro increased the recovery of both long-term repopulating HSCs and progenitor cells, and systemic administration of Dkk1 to irradiated mice increased hematopoietic recovery and improved survival. Conversely, inducible deletion of one allele of Dkk1 in Osx-expressing cells in adult mice inhibited the recovery of BM stem and progenitor cells and of complete blood counts following irradiation. Dkk1 promoted hematopoietic regeneration via both direct effects on HSCs, in which treatment with Dkk1 decreased the levels of mitochondrial reactive oxygen species and suppressed senescence, and indirect effects on BM endothelial cells, in which treatment with Dkk1 induced epidermal growth factor (EGF) secretion. Accordingly, blockade of the EGF receptor partially abrogated Dkk1-mediated hematopoietic recovery. These data identify Dkk1 as a regulator of hematopoietic regeneration and demonstrate paracrine cross-talk between BM osteolineage cells and endothelial cells in regulating hematopoietic reconstitution following injury.


Subject(s)
Bone Marrow Cells/metabolism , Cell Self Renewal , Hematopoietic Stem Cells/metabolism , Intercellular Signaling Peptides and Proteins/metabolism , Osteoblasts/metabolism , Regeneration , Transcription Factors/metabolism , Whole-Body Irradiation , Animals , Bone Marrow/metabolism , Cytokines/metabolism , Endothelial Cells/metabolism , Enzyme-Linked Immunosorbent Assay , Epidermal Growth Factor/metabolism , ErbB Receptors/antagonists & inhibitors , Flow Cytometry , Gene Expression Profiling , Hematopoietic Stem Cells/drug effects , Hematopoietic Stem Cells/radiation effects , Intercellular Signaling Peptides and Proteins/pharmacology , Mice , Mitochondria/metabolism , Radiation Injuries, Experimental , Reactive Oxygen Species , Sp7 Transcription Factor , bcl-2 Homologous Antagonist-Killer Protein/genetics , bcl-2-Associated X Protein/genetics
18.
Am J Respir Cell Mol Biol ; 56(3): 310-321, 2017 03.
Article in English | MEDLINE | ID: mdl-27749084

ABSTRACT

Diseases involving the distal lung alveolar epithelium include chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, and lung adenocarcinoma. Accurate labeling of specific cell types is critical for determining the contribution of each to the pathogenesis of these diseases. The distal lung alveolar epithelium is composed of two cell types, alveolar epithelial type 1 (AT1) and type 2 (AT2) cells. Although cell type-specific markers, most prominently surfactant protein C, have allowed detailed lineage tracing studies of AT2 cell differentiation and the cells' roles in disease, studies of AT1 cells have been hampered by a lack of genes with expression unique to AT1 cells. In this study, we performed genome-wide expression profiling of multiple rat organs together with purified rat AT2, AT1, and in vitro differentiated AT1-like cells, resulting in the identification of 54 candidate AT1 cell markers. Cross-referencing with genes up-regulated in human in vitro differentiated AT1-like cells narrowed the potential list to 18 candidate genes. Testing the top four candidate genes at RNA and protein levels revealed GRAM domain 2 (GRAMD2), a protein of unknown function, as highly specific to AT1 cells. RNA sequencing (RNAseq) confirmed that GRAMD2 is transcriptionally silent in human AT2 cells. Immunofluorescence verified that GRAMD2 expression is restricted to the plasma membrane of AT1 cells and is not expressed in bronchial epithelial cells, whereas reverse transcription-polymerase chain reaction confirmed that it is not expressed in endothelial cells. Using GRAMD2 as a new AT1 cell-specific gene will enhance AT1 cell isolation, the investigation of alveolar epithelial cell differentiation potential, and the contribution of AT1 cells to distal lung diseases.


Subject(s)
Alveolar Epithelial Cells/metabolism , Gene Expression Profiling , Organ Specificity/genetics , Animals , Biomarkers/metabolism , Epithelial Sodium Channels/metabolism , Gene Expression Regulation , Humans , Mice , Oligonucleotide Array Sequence Analysis , Rats , Reproducibility of Results , Species Specificity
19.
Cell Rep ; 17(6): 1584-1594, 2016 11 01.
Article in English | MEDLINE | ID: mdl-27806297

ABSTRACT

Imprinted genes are differentially expressed by adult stem cells, but their functions in regulating adult stem cell fate are incompletely understood. Here we show that growth factor receptor-bound protein 10 (Grb10), an imprinted gene, regulates hematopoietic stem cell (HSC) self-renewal and regeneration. Deletion of the maternal allele of Grb10 in mice (Grb10m/+ mice) substantially increased HSC long-term repopulating capacity, as compared to that of Grb10+/+ mice. After total body irradiation (TBI), Grb10m/+ mice demonstrated accelerated HSC regeneration and hematopoietic reconstitution, as compared to Grb10+/+ mice. Grb10-deficient HSCs displayed increased proliferation after competitive transplantation or TBI, commensurate with upregulation of CDK4 and Cyclin E. Furthermore, the enhanced HSC regeneration observed in Grb10-deficient mice was dependent on activation of the Akt/mTORC1 pathway. This study reveals a function for the imprinted gene Grb10 in regulating HSC self-renewal and regeneration and suggests that the inhibition of Grb10 can promote hematopoietic regeneration in vivo.


Subject(s)
Cell Self Renewal/genetics , GRB10 Adaptor Protein/deficiency , Gene Deletion , Genomic Imprinting , Hematopoietic Stem Cells/cytology , Hematopoietic Stem Cells/metabolism , Regeneration , Animals , Bone Marrow Cells/cytology , Cell Proliferation , GRB10 Adaptor Protein/metabolism , Mechanistic Target of Rapamycin Complex 1/metabolism , Mice, Inbred C57BL , Proto-Oncogene Proteins c-akt/metabolism , Signal Transduction , Whole-Body Irradiation
20.
Biochemistry ; 52(28): 4745-7, 2013 Jul 16.
Article in English | MEDLINE | ID: mdl-23806102

ABSTRACT

U1A binds U1hpII, a hairpin RNA with a 10-nucleotide loop. A U1A mutant (ΔK50ΔM51) binds U1hpII-derived hairpins with shorter loops, making it an interesting scaffold for engineering or evolving proteins that bind similarly sized disease-related hairpin RNAs. However, a more detailed understanding of complexes involving ΔK50ΔM51 is likely a prerequisite to generating such proteins. Toward this end, we measured mutational effects for complexes involving U1A ΔK50ΔM51 and U1hpII-derived hairpin RNAs with seven- or eight-nucleotide loops and identified contacts that are critical to the stabilization of these complexes. Our data provide valuable insight into sequence-selective recognition of seven- or eight-nucleotide loop hairpins by an engineered RNA binding protein.


Subject(s)
RNA-Binding Proteins/chemistry , RNA/chemistry , Fluorescence Polarization , Models, Molecular , Nucleic Acid Conformation , Protein Binding , RNA/metabolism , RNA-Binding Proteins/metabolism
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