Publications by authors named "Saloni Patel"

16 Publications

  • Page 1 of 1

Crystal structure of -butyl 4-[4-(4-fluoro-phen-yl)-2-methyl-but-3-yn-2-yl]piperazine-1-carboxyl-ate.

Acta Crystallogr E Crystallogr Commun 2021 Apr 5;77(Pt 4):360-365. Epub 2021 Mar 5.

Graduate School of Pharmaceutical Sciences, Duquesne University, 600 Forbes Ave, Pittsburgh, PA 15282, USA.

The title sterically congested piperazine derivative, CHFNO, was prepared using a modified Bruylants approach. A search of the Cambridge Structural Database identified 51 compounds possessing an butyl piperazine substructure. Of these only 14 were asymmetrically substituted on the piperazine ring and none with a synthetically useful second nitro-gen. Given the novel chemistry generating a pharmacologically useful core, determination of the crystal structure for this compound was necessary. The piperazine ring is present in a chair conformation with di-equatorial substitution. Of the two N atoms, one is hybridized while the other is hybridized. Inter-molecular inter-actions resulting from the crystal packing patterns were investigated using Hirshfeld surface analysis and fingerprint analysis. Directional weak hydrogen-bond-like inter-actions (C-H⋯O) and C-H⋯π inter-actions with the dispersion inter-actions as the major source of attraction are present in the crystal packing.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1107/S2056989021002346DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8025862PMC
April 2021

Dual inhibition of MEK1/2 and MEK5 suppresses the EMT/migration axis in triple-negative breast cancer through FRA-1 regulation.

J Cell Biochem 2021 Apr 20. Epub 2021 Apr 20.

Department of Medicine, Section of Hematology and Oncology, Tulane University School of Medicine, New Orleans, Louisiana, USA.

Triple-negative breast cancer (TNBC) presents a clinical challenge due to the aggressive nature of the disease and a lack of targeted therapies. Constitutive activation of the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) pathway has been linked to chemoresistance and metastatic progression through distinct mechanisms, including activation of epithelial-to-mesenchymal transition (EMT) when cells adopt a motile and invasive phenotype through loss of epithelial markers (CDH1), and acquisition of mesenchymal markers (VIM, CDH2). Although MAPK/ERK1/2 kinase inhibitors (MEKi) are useful antitumor agents in a clinical setting, including the Food and Drug Administration (FDA)-approved MEK1,2 dual inhibitors cobimetinib and trametinib, there are limitations to their clinical utility, primarily adaptation of the BRAF pathway and ocular toxicities. The MEK5 (HGNC: MAP2K5) pathway has important roles in metastatic progression of various cancer types, including those of the prostate, colon, bone and breast, and elevated levels of ERK5 expression in breast carcinomas are linked to a worse prognoses in TNBC patients. The purpose of this study is to explore MEK5 regulation of the EMT axis and to evaluate a novel pan-MEK inhibitor on clinically aggressive TNBC cells. Our results show a distinction between the MEK1/2 and MEK5 cascades in maintenance of the mesenchymal phenotype, suggesting that the MEK5 pathway may be necessary and sufficient in EMT regulation while MEK1/2 signaling further sustains the mesenchymal state of TNBC cells. Furthermore, additive effects on MET induction are evident through the inhibition of both MEK1/2 and MEK5. Taken together, these data demonstrate the need for a better understanding of the individual roles of MEK1/2 and MEK5 signaling in breast cancer and provide a rationale for the combined targeting of these pathways to circumvent compensatory signaling and subsequent therapeutic resistance.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jcb.29916DOI Listing
April 2021

Molecular Mechanisms of Epithelial to Mesenchymal Transition Regulated by ERK5 Signaling.

Biomolecules 2021 01 29;11(2). Epub 2021 Jan 29.

Department of Pharmacology, School of Pharmacy, Duquesne University, Pittsburgh, PA 15282, USA.

Extracellular signal-regulated kinase (ERK5) is an essential regulator of cancer progression, tumor relapse, and poor patient survival. Epithelial to mesenchymal transition (EMT) is a complex oncogenic process, which drives cell invasion, stemness, and metastases. Activators of ERK5, including mitogen-activated protein kinase 5 (MEK5), tumor necrosis factor α (TNF-α), and transforming growth factor-β (TGF-β), are known to induce EMT and metastases in breast, lung, colorectal, and other cancers. Several downstream targets of the ERK5 pathway, such as myocyte-specific enhancer factor 2c (MEF2C), activator protein-1 (AP-1), focal adhesion kinase (FAK), and c-Myc, play a critical role in the regulation of EMT transcription factors SNAIL, SLUG, and β-catenin. Moreover, ERK5 activation increases the release of extracellular matrix metalloproteinases (MMPs), facilitating breakdown of the extracellular matrix (ECM) and local tumor invasion. Targeting the ERK5 signaling pathway using small molecule inhibitors, microRNAs, and knockdown approaches decreases EMT, cell invasion, and metastases via several mechanisms. The focus of the current review is to highlight the mechanisms which are known to mediate cancer EMT via ERK5 signaling. Several therapeutic approaches that can be undertaken to target the ERK5 pathway and inhibit or reverse EMT and metastases are discussed.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/biom11020183DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7911413PMC
January 2021

Evaluating the Facilitators, Barriers, and Medical Outcomes Commensurate with the Use of Assistive Technology to Support People with Dementia: A Systematic Review Literature.

Healthcare (Basel) 2020 Aug 18;8(3). Epub 2020 Aug 18.

School of Health Administration, Texas State University, San Marcos, TX 78666, USA.

: Assistive technologies (AT) have been used to improve the daily living conditions of people living with dementia (PWD). Research supports the positive impact of the use of AT such as decreased burden on caregivers and behavioral support for people with dementia. Four reviews in the last six years have analyzed AT and PWD, but none have incorporated the dimension of medical outcomes. The purpose of this review is to identify the facilitators, barriers, and medical outcomes commensurate with the use of AT with PWD. This review queried The Cumulative Index of Nursing and Allied Health Literature (CINAHL), Web of Science, Science Direct, and PubMed databases for peer-reviewed publications in the last five years for facilitators, barriers, and medical outcomes commensurate with the use of AT with PWD. The study is reported and conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) and the Kruse Protocol for conducting a systematic review. 48 studies were analyzed. Fourteen types of AT, 17 facilitators, 17 barriers, and 16 medical outcomes were identified in the literature. The two most frequently mentioned ATs were cognitive stimulators (9/48, 19%) and social robots (5/48, 10%). The two most frequently mentioned facilitators were caregivers want AT (8/68, 12%) and enables increased independence (7/68, 10%). The top two barriers were cost (8/75, 11%) and PWD reject AT (8/75, 11%). The top medical outcomes were improved cognitive abilities (6/69, 9%), increased activities of daily living (ADLs), and increased autonomy (each at 5/69, 7%): Zero negative outcomes were reported. The systematic review revealed the positive relations that occur when PWD and their caregivers use AT. Although many reservations surrounding the use of AT exist, a majority of the literature shows a positive effect of its use. Research supports a strong support for AT by caregivers due to many positive medical outcomes, but also a reticence to adopt by PWD. If ATs for PWD are a way to reduce stress on caregivers, barriers of cost and complexity need to be addressed through health policy or grants.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/healthcare8030278DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7551699PMC
August 2020

Correction: Keratinocyte differentiation promotes ER stress-dependent lysosome biogenesis.

Cell Death Dis 2019 Oct 3;10(10):740. Epub 2019 Oct 3.

Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, 560012, India.

Following publication of this article, the authors realized there was an error in Figure 2b that needed correction. The TFEB panel of Figure 2b (total lysate) appears to be the same as the TFEB panel of Figure 2e (cytosolic fraction); the TFE3 panels of Figure 2b (total lysate) appear to be the same as the TFE3 panels of Figure 2e (cytosolic fraction) which happened during image assembly.This error did not impact the scientific conclusions of the article.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41419-019-1981-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6776641PMC
October 2019

Tobacco pack display at hospitality venues after the introduction of standardised tobacco packaging in New Zealand: a field observation study.

BMJ Open 2019 09 6;9(9):e027868. Epub 2019 Sep 6.

Department of Public Health, University of Otago, Wellington, New Zealand

Objectives: In March 2018, New Zealand (NZ) introduced standardised tobacco packaging that also featured new pictorial warnings, with implementation completed by early June 2018. We evaluated how the new packaging affected tobacco pack displays in outdoor areas of hospitality venues.

Design: Before-and-after descriptive field observation study.

Setting: Central city area of the capital city of NZ (Wellington).

Participants: Observations of people smoking and tobacco packs were made at 56 hospitality venues with outdoor tables (2422 separate venue observations), after the introduction of standardised tobacco packaging. Comparisons were made with a prior study in the same setting, from a time when tobacco packaging still featured brand imagery.

Results: A total of 8191 patrons, 1113 active smokers and 889 packs and pouches (522 of known orientation) were observed over 2422 venue observations. There were 0.80 visible packs per active smoker in 2018, compared with 1.26 in 2014 (risk ratio (RR)=0.64, 95% CI 0.60 to 0.67, p<0.0001). The new packs in 2018 were also less likely to be displayed face-up, compared with packs in 2014, which had brand imagery on the front face (RR=0.77, 95% CI 0.72 to 0.83, p<0.0001). Pack and pouch display (RR=3.09 in 2014 and 3.10 in 2018) and active smoking (RR=3.16 in 2014 compared with 3.32 in 2018) were higher at venues without children present, compared with venues with children present (this finding was consistent over time).

Conclusions: The reduction in the number of visible packs per active smoker, along with the reduction in face-up positioning of packs, suggests that smokers found the new standardised packs less attractive. Countries introducing standardised packaging should consider evaluating social display of tobacco packaging.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1136/bmjopen-2018-027868DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6731942PMC
September 2019

Premature ventricular contractions activate vagal afferents and alter autonomic tone: implications for premature ventricular contraction-induced cardiomyopathy.

Am J Physiol Heart Circ Physiol 2019 09 19;317(3):H607-H616. Epub 2019 Jul 19.

University of California, Los Angeles Cardiac Arrhythmia Center, Los Angeles, California.

Mechanisms behind development of premature ventricular contraction (PVC)-induced cardiomyopathy remain unclear. PVCs may adversely modulate the autonomic nervous system to promote development of heart failure. Afferent neurons in the inferior vagal (nodose) ganglia transduce cardiac activity and modulate parasympathetic output. Effects of PVCs on cardiac parasympathetic efferent and vagal afferent neurotransmission are unknown. The purpose of this study was to evaluate effects of PVCs on vagal afferent neurotransmission and compare these effects with a known powerful autonomic modulator, myocardial ischemia. In 16 pigs, effects of variably coupled PVCs on heart rate variability (HRV) and vagal afferent neurotransmission were evaluated. Direct nodose neuronal recordings were obtained in vivo, and cardiac-related afferent neurons were identified based on their response to cardiovascular interventions, including ventricular chemical and mechanical stimuli, left anterior descending (LAD) coronary artery occlusion, and variably coupled PVCs. On HRV analysis before versus after PVCs, parasympathetic tone decreased (normalized high frequency: 83.6 ± 2.8 to 72.5 ± 5.3; < 0.05). PVCs had a powerful impact on activity of cardiac-related afferent neurons, altering activity of 51% of neurons versus 31% for LAD occlusion ( < 0.05 vs. LAD occlusion and all other cardiac interventions). Both chemosensitive and mechanosensitive neurons were activated by PVCs, and their activity remained elevated even after cessation of PVCs. Cardiac afferent neural responses to PVCs were greater than any other intervention, including ischemia of similar duration. These data suggest that even brief periods of PVCs powerfully modulate vagal afferent neurotransmission, reflexly decreasing parasympathetic efferent tone. Premature ventricular contractions (PVCs) are common in many patients and, at an increased burden, are known to cause heart failure. This study determined that PVCs powerfully modulate cardiac vagal afferent neurotransmission (exerting even greater effects than ventricular ischemia) and reduce parasympathetic efferent outflow to the heart. PVCs activated both mechano- and chemosensory neurons in the nodose ganglia. These peripheral neurons demonstrated adaptation in response to PVCs. This study provides additional data on the potential role of the autonomic nervous system in PVC-induced cardiomyopathy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1152/ajpheart.00286.2019DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6766725PMC
September 2019

Keratinocyte differentiation promotes ER stress-dependent lysosome biogenesis.

Cell Death Dis 2019 03 19;10(4):269. Epub 2019 Mar 19.

Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, 560012, India.

Keratinocytes maintain epidermal integrity through cellular differentiation. This process enhances intraorganelle digestion in keratinocytes to sustain nutritional and calcium-ionic stresses observed in upper skin layers. However, the molecular mechanisms governing keratinocyte differentiation and concomitant increase in lysosomal function is poorly understood. Here, by using primary neonatal human epidermal keratinocytes, we identified the molecular link between signaling pathways and cellular differentiation/lysosome biogenesis. Incubation of keratinocytes with CaCl induces differentiation with increased cell size and early differentiation markers. Further, differentiated keratinocytes display enhanced lysosome biogenesis generated through ATF6-dependent ER stress signaling, but independent of mTOR-MiT/TFE pathway. In contrast, chemical inhibition of mTORC1 accelerates calcium-induced keratinocyte differentiation, suggesting that activation of autophagy promotes the differentiation process. Moreover, differentiation of keratinocytes results in lysosome dispersion and Golgi fragmentation, and the peripheral lysosomes showed colocalization with Golgi-tethering proteins, suggesting that these organelles possibly derived from Golgi. In line, inhibition of Golgi function, but not the depletion of Golgi-tethers or altered lysosomal acidity, abolishes keratinocyte differentiation and lysosome biogenesis. Thus, ER stress regulates lysosome biogenesis and keratinocyte differentiation to maintain epidermal homeostasis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41419-019-1478-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6425001PMC
March 2019

Self-Assembly of a Dentinogenic Peptide Hydrogel.

ACS Omega 2018 Jun 4;3(6):5980-5987. Epub 2018 Jun 4.

Department of Biomedical Engineering and Department of Chemical, Biological and Pharmaceutical Engineering, New Jersey Institute of Technology, Newark, New Jersey 07102, United States.

Current standard of care for treating infected dental pulp, root canal therapy, retains the physical properties of the tooth to a large extent, but does not aim to rejuvenate the pulp tissue. Tissue-engineered acellular biomimetic hydrogels have great potential to facilitate the regeneration of the tissue through the recruitment of autologous stem cells. We propose the use of a dentinogenic peptide that self-assembles into β-sheet-based nanofibers that constitute a biodegradable and injectable hydrogel for support of dental pulp stem cells. The peptide backbone contains a β-sheet-forming segment and a matrix extracellular phosphoglycoprotein mimic sequence at the C-terminus. The high epitope presentation of the functional moiety in the self-assembled nanofibers may enable recapitulation of a functional niche for the survival and proliferation of autologous cells. We elucidated the hierarchical self-assembly of the peptide through biophysical techniques, including scanning electron microscopy and atomic force microscopy. The material property of the self-assembled hydrogel was probed though oscillatory rheometry, demonstrating its thixotropic nature. We also demonstrate the cytocompatibility of the hydrogel with respect to fibroblasts and dental pulp stem cells. The self-assembled peptide platform holds promise for guided dentinogenesis and it can be tailored to a variety of applications in soft tissue engineering and translational medicine in the future.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acsomega.8b00347DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6045409PMC
June 2018

Low-dose tamoxifen treatment in juvenile males has long-term adverse effects on the reproductive system: implications for inducible transgenics.

Sci Rep 2017 08 21;7(1):8991. Epub 2017 Aug 21.

MRC Centre for Reproductive Health, The Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, UK.

The tamoxifen-inducible Cre system is a popular transgenic method for controlling the induction of recombination by Cre at a specific time and in a specific cell type. However, tamoxifen is not an inert inducer of recombination, but an established endocrine disruptor with mixed agonist/antagonist activity acting via endogenous estrogen receptors. Such potentially confounding effects should be controlled for, but >40% of publications that have used tamoxifen to generate conditional knockouts have not reported even the minimum appropriate controls. To highlight the importance of this issue, the present study investigated the long-term impacts of different doses of a single systemic tamoxifen injection on the testis and the wider endocrine system. We found that a single dose of tamoxifen less than 10% of the mean dose used for recombination induction, caused adverse effects to the testis and to the reproductive endocrine system that persisted long-term. These data raise significant concerns about the widespread use of tamoxifen induction of recombination, and highlight the importance of including appropriate controls in all pathophysiological studies using this means of induction.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-017-09016-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5566418PMC
August 2017

Polymyxin B in combination with meropenem against carbapenemase-producing Klebsiella pneumoniae: pharmacodynamics and morphological changes.

Int J Antimicrob Agents 2017 Feb 23;49(2):224-232. Epub 2016 Dec 23.

School of Pharmacy and Pharmaceutical Sciences, University at Buffalo, SUNY, Buffalo, NY, USA. Electronic address:

Combination therapy provides a useful therapeutic approach to overcome resistance until new antibiotics become available. In this study, the pharmacodynamics, including the morphological effects, of polymyxin B (PMB) and meropenem alone and in combination against KPC-producing Klebsiella pneumoniae clinical isolates was examined. Ten clinical isolates were obtained from patients undergoing treatment for mediastinitis. KPCs were identified and MICs were measured using microbroth dilution. Time-kill studies were conducted over 24 h with PMB (0.5-16 mg/L) and meropenem (20-120 mg/L) alone or in combination against an initial inoculum of ca. 10 CFU/mL. Scanning electron microscopy (SEM) was employed to analyse changes in bacterial morphology after treatment, and the log change method was used to quantify the pharmacodynamic effect. All isolates harboured the bla gene and were resistant to meropenem (MICs ≥8 mg/L). Clinically relevant PMB concentrations (0.5, 1.0 and 2.0 mg/L) in combination with meropenem were synergistic against all isolates except BRKP28 (polymyxin- and meropenem-resistant, both MICs >128 mg/L). All PMB and meropenem concentrations in combination were bactericidal against polymyxin-susceptible isolates with meropenem MICs ≤16 mg/L. SEM revealed extensive morphological changes following treatment with PMB in combination with meropenem compared with the changes observed with each individual agent. Additionally, morphological changes decreased with increasing resistance profiles of the isolate, i.e. increasing meropenem MIC. These antimicrobial effects may not only be a summation of the effects due to each antibiotic but also a result of differential action that likely inhibits protective mechanisms in bacteria.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ijantimicag.2016.10.025DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5786158PMC
February 2017

Genetic Analysis Reveals a Hierarchy of Interactions between Polycystin-Encoding Genes and Genes Controlling Cilia Function during Left-Right Determination.

PLoS Genet 2016 06 6;12(6):e1006070. Epub 2016 Jun 6.

MRC Harwell, Harwell Science and Innovation Campus, Oxfordshire, United Kingdom.

During mammalian development, left-right (L-R) asymmetry is established by a cilia-driven leftward fluid flow within a midline embryonic cavity called the node. This 'nodal flow' is detected by peripherally-located crown cells that each assemble a primary cilium which contain the putative Ca2+ channel PKD2. The interaction of flow and crown cell cilia promotes left side-specific expression of Nodal in the lateral plate mesoderm (LPM). Whilst the PKD2-interacting protein PKD1L1 has also been implicated in L-R patterning, the underlying mechanism by which flow is detected and the genetic relationship between Polycystin function and asymmetric gene expression remains unknown. Here, we characterize a Pkd1l1 mutant line in which Nodal is activated bilaterally, suggesting that PKD1L1 is not required for LPM Nodal pathway activation per se, but rather to restrict Nodal to the left side downstream of nodal flow. Epistasis analysis shows that Pkd1l1 acts as an upstream genetic repressor of Pkd2. This study therefore provides a genetic pathway for the early stages of L-R determination. Moreover, using a system in which cultured cells are supplied artificial flow, we demonstrate that PKD1L1 is sufficient to mediate a Ca2+ signaling response after flow stimulation. Finally, we show that an extracellular PKD domain within PKD1L1 is crucial for PKD1L1 function; as such, destabilizing the domain causes L-R defects in the mouse. Our demonstration that PKD1L1 protein can mediate a response to flow coheres with a mechanosensation model of flow sensation in which the force of fluid flow drives asymmetric gene expression in the embryo.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1371/journal.pgen.1006070DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4894641PMC
June 2016

Design, synthesis and anti-HIV activity of novel quinoxaline derivatives.

Eur J Med Chem 2016 Jul 11;117:230-40. Epub 2016 Apr 11.

Department of Pharmaceutical Chemistry, Institute of Pharmacy, Nirma University, Ahmedabad, 382 481, India. Electronic address:

In order to design novel anti-HIV agents, pharmacophore modelling, virtual screening, 3D-QSAR and molecular docking studies were performed. Pharmacophore model was generated using 17 structurally diverse molecules using DISCOtech followed by refinement with GASP module of Sybyl X. The best model containing four features; two donor sites, one acceptor atom and one hydrophobic region; was used as a query for virtual screening in NCI database and 6 compounds with Qfit value ≥98 were retrieved. The quinoxaline ring which is the bio-isostere of pteridine ring, retrieved as a hit in virtual screening, was selected as a core moiety. 3D-QSAR was carried on thirty five 5-hydroxy-6-oxo-1,6-dihydropyrimidine-4-carboxamide derivatives. Contour map analysis of best CoMFA and CoMSIA model suggested incorporation of hydrophobic, bulky and electronegative groups to increase potency of the designed compounds. 50 quinoxaline derivatives with different substitutions were designed on basis of both ligand based drug design approaches and were mapped on the best pharmacophore model. From this, best 32 quinoxaline derivatives were docked onto the active site of integrase enzyme and in-silico ADMET properties were also predicted. From this data, synthesis of top 7 quinoxaline derivatives was carried out and were characterized using Mass, (1)H-NMR and (13)C-NMR spectroscopy. Purity of compounds were checked using HPLC. These derivatives were evaluated for anti-HIV activity on III-B strain of HIV-1 and cytotoxicity studies were performed on VERO cell line. Two quinoxaline derivatives (7d and 7e) showed good results, which can be further explored to develop novel anti-HIV agents.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ejmech.2016.04.019DOI Listing
July 2016

Oocyte glycoproteins regulate the form and function of the follicle basal lamina and theca cells.

Dev Biol 2015 May 31;401(2):287-98. Epub 2014 Dec 31.

Nuffield Department of Obstetrics and Gynaecology, University of Oxford, Women׳s Centre, Level 3, John Radcliffe Hospital, Oxford OX3 9DU, UK. Electronic address:

Maintaining follicle integrity during development, whereby each follicle is a functional unit containing a single oocyte, is essential for the generation of healthy oocytes. However, the mechanisms that regulate this critical function have not been determined. In this paper we investigate the role of the oocyte in maintaining follicle development. To investigate this role, we use a mouse model with oocyte-specific deletion of C1galt1 which is required for the generation of core 1-derived O-glycans. The loss of oocyte-generated O-glycans results in the joining of follicles and the generation of Multiple-Oocyte Follicles (MOFs). The aim was to determine how Mutant follicle development is modified thus enabling follicles to join. Extracellular matrix and follicle permeability were studied using histology, immunohistochemistry and electron microscopy (EM). In ovaries containing Mutant Oocytes, the Follicle basal lamina (FBL) is altered both functionally and structurally from the primary stage onwards with Mutant follicles possessing unexpectedly thicker FBL. In Mutant ovaries, the theca cell layer is also modified with intermingling of theca between adjacent follicles. MOF function was analysed but despite increased numbers of preantral MOFs in Mutants, these do not reach the preovulatory stage after gonadotrophin stimulation. We propose a model describing how oocyte initiated changes in FBL and theca cells result in follicles joining. These data reveal new and important roles for the oocyte in follicle development and follicle integrity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ydbio.2014.12.024DOI Listing
May 2015

ATMIN is a transcriptional regulator of both lung morphogenesis and ciliogenesis.

Development 2014 Oct;141(20):3966-77

Mammalian Genetics Unit, MRC Harwell, Harwell Science and Innovation Campus, Oxfordshire OX11 0RD, UK

Initially identified in DNA damage repair, ATM-interactor (ATMIN) further functions as a transcriptional regulator of lung morphogenesis. Here we analyse three mouse mutants, Atmin(gpg6/gpg6), Atmin(H210Q/H210Q) and Dynll1(GT/GT), revealing how ATMIN and its transcriptional target dynein light chain LC8-type 1 (DYNLL1) are required for normal lung morphogenesis and ciliogenesis. Expression screening of ciliogenic genes confirmed Dynll1 to be controlled by ATMIN and further revealed moderately altered expression of known intraflagellar transport (IFT) protein-encoding loci in Atmin mutant embryos. Significantly, Dynll1(GT/GT) embryonic cilia exhibited shortening and bulging, highly similar to the characterised retrograde IFT phenotype of Dync2h1. Depletion of ATMIN or DYNLL1 in cultured cells recapitulated the in vivo ciliogenesis phenotypes and expression of DYNLL1 or the related DYNLL2 rescued the effects of loss of ATMIN, demonstrating that ATMIN primarily promotes ciliogenesis by regulating Dynll1 expression. Furthermore, DYNLL1 as well as DYNLL2 localised to cilia in puncta, consistent with IFT particles, and physically interacted with WDR34, a mammalian homologue of the Chlamydomonas cytoplasmic dynein 2 intermediate chain that also localised to the cilium. This study extends the established Atmin-Dynll1 relationship into a developmental and a ciliary context, uncovering a novel series of interactions between DYNLL1, WDR34 and ATMIN. This identifies potential novel components of cytoplasmic dynein 2 and furthermore provides fresh insights into the molecular pathogenesis of human skeletal ciliopathies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1242/dev.107755DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4197704PMC
October 2014

Static respiratory cilia associated with mutations in Dnahc11/DNAH11: a mouse model of PCD.

Hum Mutat 2012 Mar 29;33(3):495-503. Epub 2011 Dec 29.

Primary Ciliary Dyskinesia Group, Clinical and Experimental Sciences, University of Southampton Faculty of Medicine, Southampton NIHR Respiratory Biomedical Research Unit, Southampton General Hospital, Southampton, UK.

Primary ciliary dyskinesia (PCD) is an inherited disorder causing significant upper and lower respiratory tract morbidity and impaired fertility. Half of PCD patients show abnormal situs. Human disease loci have been identified but a mouse model without additional deleterious defects is elusive. The inversus viscerum mouse, mutated at the outer arm dynein heavy chain 11 locus (Dnahc11) is a known model of heterotaxy. We demonstrated immotile tracheal cilia with normal ultrastructure and reduced sperm motility in the Dnahc11(iv) mouse. This is accompanied by gross rhinitis, sinusitis, and otitis media, all indicators of human PCD. Strikingly, age-related progression of the disease is evident. The Dnahc11(iv) mouse is robust, lacks secondary defects, and requires no intervention to precipitate the phenotype. Together these findings show the Dnahc11(iv) mouse to be an excellent model of many aspects of human PCD. Mutation of the homologous human locus has previously been associated with hyperkinetic tracheal cilia in PCD. Two PCD patients with normal ciliary ultrastructure, one with immotile and one with hyperkinetic cilia were found to carry DNAH11 mutations. Three novel DNAH11 mutations were detected indicating that this gene should be investigated in patients with normal ciliary ultrastructure and static, as well as hyperkinetic cilia.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/humu.22001DOI Listing
March 2012