scholarly journals INPP5E controls ciliary localization of phospholipids and odor response kinetics in a mouse model of Joubert syndrome

2018 ◽  
Author(s):  
Kirill Ukhanov ◽  
Cedric Uytingco ◽  
Warren Green ◽  
Lian Zhang ◽  
Stephane Schurmans ◽  
...  
Keyword(s):  
Cell Biology ◽  
Primary Cilia ◽  
Membrane Lipids ◽  
Phospholipid Composition ◽  
Joubert Syndrome ◽  
Basic Knowledge ◽  
Dent Disease ◽  
Inactivation Kinetics ◽  
Assisted Delivery ◽  
Ciliary Localization

AbstractCiliopathies manifested in part by a dysfunction of several phosphoinositide 5’phosphatases constitute Lowes, Dent disease 2 and Joubert syndromes through critical involvement of properly functioning primary cilia (PC). We showed that deletion of INPP5E under the control of OMP-Cre in mature mouse olfactory sensory neurons (OSNs) led to a dramatic redistribution of PI(4,5)P2 (PIP2) in cilia, significant reduction of PI(3,4)P2 and enrichment of PI(3,4,5)P3 in knobs. Redistribution of the phospholipids accompanied marked elongation of cilia in INPP5E-OMP knockout (KO) OSNs. Such a dramatic remodeling of phospholipid composition however did not affect other integral membrane lipids (cholesterol, sphingomyelin, glycosylated phosphaditylinositol, phosphatidylserine). Proteins known to bind with high affinity PIP2 entered the cilia of the KO OSNs. Loss of INPP5E did not affect ciliary localization of endogenous olfactory receptor M71/M72 or distribution and movement of IFT122 particles implicating independent of phospholipids mechanism of retrograde protein transport in cilia of mature OSNs. Net odor sensitivity and response magnitude as measured by EOG was not affected by the mutation. However, odor adaptation in the KO mouse was significantly impaired resulting in less efficient recovery and altered inactivation kinetics of the odor response at the EOG and single-cell level. These findings implicate phosphoinositide-dependent regulation of active Ca2+ extrusion in OSNs whereby controlling the rate of sensory adaptation.Significance statementCurrently there are little if any available treatment to cure congenital ciliopathies. This is in part due to lack of basic knowledge of cilia biology. Olfactory cilia as well as primary cilia appear to be a phospholipid privileged organelle distinct from the rest of plasma membrane albeit sharing its continuity. We characterized distribution of several critically important for cell biology phospholipids and showed that their balance, especially of PIP2, is disrupted in Joubert syndrome animal model and has functional implications. Virally assisted delivery of wild type INPP5E to the mutant OSNs was able to restore localization of PIP2 and rescued impaired response to odor.

scholarly journals INPP5E controls ciliary localization of phospholipids and odor response in olfactory sensory neurons

2021 ◽  
pp. jcs.258364
Author(s):  
Kirill Ukhanov ◽  
Cedric Uytingco ◽  
Warren Green ◽  
Lian Zhang ◽  
Stephane Schurmans ◽  
...  
Keyword(s):  
Sensory Neurons ◽  
Primary Cilia ◽  
Electrical Response ◽  
Joubert Syndrome ◽  
Gene Replacement ◽  
Inactivation Kinetics ◽  
Olfactory Sensory Neurons ◽  
Efficient Recovery ◽  
And Function ◽  
Ciliary Localization

The lipid composition of the primary cilia membrane is emerging as a critical regulator of cilia formation, maintenance, and function. Here, we show that conditional deletion of the phosphoinositide 5’-phosphatase gene, Inpp5e, causative of Joubert syndrome in terminally developed mouse olfactory sensory neurons (OSNs) led to a dramatic remodeling of ciliary phospholipids that was accompanied by marked elongation of cilia. PI(4,5)P2 normally restricted to the proximal segment redistributed to the entire length of cilia in Inpp5e knockout mice with a reduction in PI(3,4)P2 and elevation of PI(3,4,5)P3 in the dendritic knob. The redistribution of phosphoinositides impaired odor adaptation, resulting in less efficient recovery and altered inactivation kinetics of the odor-evoked electrical response and the odor-induced elevation of cytoplasmic Ca2+. Gene replacement by adenoviral expression of Inpp5e restored the ciliary localization of PI(4,5)P2 and odor response kinetics in OSNs. Our findings support the role of phosphoinositides as a modulator of the odor response and in ciliary biology of native multi-ciliated OSNs.

scholarly journals Update on Giardia: Highlights from the seventh International Giardia and Cryptosporidium Conference

Parasite ◽  
2020 ◽  
Vol 27 ◽  
pp. 49 ◽  
Author(s):  
André G. Buret ◽  
Simone M. Cacciò ◽  
Loïc Favennec ◽  
Staffan Svärd
Keyword(s):  
Cell Biology ◽  
Health Management ◽  
Giardia Duodenalis ◽  
Basic Research ◽  
Basic Knowledge ◽  
Future Research ◽  
World Knowledge ◽  
Main Research ◽  
Research Perspectives ◽  
New Findings

Although Giardia duodenalis is recognized as one of the leading causes of parasitic human diarrhea in the world, knowledge of the mechanisms of infection is limited, as the pathophysiological consequences of infection remain incompletely elucidated. Similarly, the reason for and consequences of the very specific genome-organization in this parasite with 2 active nuclei is only partially known. Consistent with its tradition, the 7th International Giardia and Cryptosporidium Conference (IGCC 2019) was held from June 23 to 26, 2019, at the Faculty of Medicine and Pharmacy of the University of Rouen-Normandie, France, to discuss current research perspectives in the field. This renowned event brought together an international delegation of researchers to present and debate recent advances and identify the main research themes and knowledge gaps. The program for this interdisciplinary conference included all aspects of host-parasite relationships, from basic research to applications in human and veterinary medicine, as well as the environmental issues raised by water-borne parasites and their epidemiological consequences. With regard to Giardia and giardiasis, the main areas of research for which new findings and the most impressive communications were presented and discussed included: parasite ecology and epidemiology of giardiasis, Giardia-host interactions, and cell biology of Giardia, genomes and genomic evolution. The high-quality presentations discussed at the Conference noted breakthroughs and identified new opportunities that will inspire researchers and funding agencies to stimulate future research in a “one health” approach to improve basic knowledge and clinical and public health management of zoonotic giardiasis.

scholarly journals Pathogenic alleles in microtubule, secretory granule and extracellular matrix-related genes in familial keratoconus

2021 ◽  
Author(s):  
Vishal Shinde ◽  
Nara Sobreira ◽  
Elizabeth S Wohler ◽  
George Maiti ◽  
Nan Hu ◽  
...  
Keyword(s):  
Amino Acid ◽  
Cell Cultures ◽  
Cell Biology ◽  
Stromal Cell ◽  
Primary Cilia ◽  
Single Amino Acid ◽  
European Ancestry ◽  
Base Substitution ◽  
Amino Acid Substitutions ◽  
Functional Link

Abstract Keratoconus is a common corneal defect with a complex genetic basis. By whole exome sequencing of affected members from 11 multiplex families of European ancestry, we identified 23 rare, heterozygous, potentially pathogenic variants in 8 genes. These include nonsynonymous single amino acid substitutions in HSPG2, EML6 and CENPF in two families each, and in NBEAL2, LRP1B, PIK3CG and MRGPRD in three families each; ITGAX had nonsynonymous single amino acid substitutions in two families and an indel with a base substitution producing a nonsense allele in the third family. Only HSPG2, EML6 and CENPF have been associated with ocular phenotypes previously. With the exception of MRGPRD and ITGAX, we detected the transcript and encoded protein of the remaining genes in the cornea and corneal cell cultures. Cultured stromal cells showed cytoplasmic punctate staining of NBEAL2, staining of the fibrillar cytoskeletal network by EML6, while CENPF localized to the basal body of primary cilia. We inhibited the expression of HSPG2, EML6, NBEAL2 and CENPF in stromal cell cultures and assayed for the expression of COL1A1 as a readout of corneal matrix production. An upregulation in COL1A1 after siRNA inhibition indicated their functional link to stromal cell biology. For ITGAX, encoding a leukocyte integrin, we assayed its level in the sera of 3 affected families compared with 10 unrelated controls to detect an increase in all affecteds. Our study identified genes that regulate the cytoskeleton, protein trafficking and secretion, barrier tissue function and response to injury and inflammation, as being relevant to keratoconus.

scholarly journals Advances in Adoptive Cell Therapy Using Induced Pluripotent Stem Cell-Derived T Cells

2021 ◽  
Vol 12 ◽  
Author(s):  
Ratchapong Netsrithong ◽  
Methichit Wattanapanitch
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
Cell Biology ◽  
Ex Vivo ◽  
Adoptive Cell Therapy ◽  
Basic Knowledge ◽  
Car T Cells ◽  
Car T ◽  
Induced Pluripotent

Adoptive cell therapy (ACT) using chimeric antigen receptor (CAR) T cells holds impressive clinical outcomes especially in patients who are refractory to other kinds of therapy. However, many challenges hinder its clinical applications. For example, patients who undergo chemotherapy usually have an insufficient number of autologous T cells due to lymphopenia. Long-term ex vivo expansion can result in T cell exhaustion, which reduces the effector function. There is also a batch-to-batch variation during the manufacturing process, making it difficult to standardize and validate the cell products. In addition, the process is labor-intensive and costly. Generation of universal off-the-shelf CAR T cells, which can be broadly given to any patient, prepared in advance and ready to use, would be ideal and more cost-effective. Human induced pluripotent stem cells (iPSCs) provide a renewable source of cells that can be genetically engineered and differentiated into immune cells with enhanced anti-tumor cytotoxicity. This review describes basic knowledge of T cell biology, applications in ACT, the use of iPSCs as a new source of T cells and current differentiation strategies used to generate T cells as well as recent advances in genome engineering to produce next-generation off-the-shelf T cells with improved effector functions. We also discuss challenges in the field and future perspectives toward the final universal off-the-shelf immunotherapeutic products.

scholarly journals A Diagnostic Assessment for Introductory Molecular and Cell Biology

2010 ◽  
Vol 9 (4) ◽  
pp. 453-461 ◽  
Author(s):  
Jia Shi ◽  
William B. Wood ◽  
Jennifer M. Martin ◽  
Nancy A. Guild ◽  
Quentin Vicens ◽  
...  
Keyword(s):  
Student Learning ◽  
Cell Biology ◽  
Item Difficulty ◽  
Multiple Choice ◽  
Basic Knowledge ◽  
Learning Goals ◽  
Multiple Choice Questions ◽  
Statistical Parameters ◽  
Reliable Instrument ◽  
Selection Of

We have developed and validated a tool for assessing understanding of a selection of fundamental concepts and basic knowledge in undergraduate introductory molecular and cell biology, focusing on areas in which students often have misconceptions. This multiple-choice Introductory Molecular and Cell Biology Assessment (IMCA) instrument is designed for use as a pre- and posttest to measure student learning gains. To develop the assessment, we first worked with faculty to create a set of learning goals that targeted important concepts in the field and seemed likely to be emphasized by most instructors teaching these subjects. We interviewed students using open-ended questions to identify commonly held misconceptions, formulated multiple-choice questions that included these ideas as distracters, and reinterviewed students to establish validity of the instrument. The assessment was then evaluated by 25 biology experts and modified based on their suggestions. The complete revised assessment was administered to more than 1300 students at three institutions. Analysis of statistical parameters including item difficulty, item discrimination, and reliability provides evidence that the IMCA is a valid and reliable instrument with several potential uses in gauging student learning of key concepts in molecular and cell biology.

Modulation of quorum sensing in Pseudomonas aeruginosa through alteration of membrane properties

Microbiology ◽  
2005 ◽  
Vol 151 (8) ◽  
pp. 2529-2542 ◽  
Author(s):  
Christine Baysse ◽  
Méabh Cullinane ◽  
Valérie Dénervaud ◽  
Elizabeth Burrowes ◽  
J. Maxwell Dow ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Membrane Fluidity ◽  
Environmental Conditions ◽  
Adaptive Response ◽  
Environmental Changes ◽  
Membrane Lipids ◽  
Phospholipid Composition ◽  
Genetically Engineered ◽  
Membrane Properties

Changes in the cellular envelope are major physiological adaptations that occur when micro-organisms encounter extreme environmental conditions. An appropriate degree of membrane fluidity is crucial for survival, and alteration of membrane lipids is an essential adaptive response. Emerging data suggest that microbial cells may recognize alterations in their membrane viscosity resulting from certain environmental changes as a trigger for adaptive cellular responses. In Pseudomonas aeruginosa, the quorum-sensing (QS) system involves a complex regulatory circuitry that coordinates the expression of genes according to a critical population density. Interestingly, it has been shown that the QS system of P. aeruginosa can also be activated by nutritional stress, independently of the cell density, and therefore may be part of a more general adaptive response to stressful environmental conditions. In order to examine the proposed link between membrane properties and stress signalling, the effects of genetically engineered alterations of the membrane phospholipid composition of P. aeruginosa PAO1 on the activation of the stringent response and the QS system were examined. The lptA gene encoding a functional homologue of PlsC, an Escherichia coli enzyme that catalyses the second step of the phospholipid biosynthesis pathway, was identified and disrupted. Inactivation of lptA altered the fatty acid profile of phospholipids and the membrane properties, resulting in decreased membrane fluidity. This resulted in a premature production of the QS signals N-butanoyl- and N-hexanoyl-homoserine lactone (C4-HSL and C6-HSL) and a repression of 2-heptyl-3-hydroxy-4-quinolone (PQS) synthesis at later growth phases. The effects on C4- and C6-HSL depended upon the expression of relA, encoding the (p)ppGpp alarmone synthase, which was increased in the lptA mutant. Together, the findings support the concept that alterations in membrane properties can act as a trigger for stress-related gene expression.

scholarly journals Hematopoietic Stem Cell Development, Niches, and Signaling Pathways

2012 ◽  
Vol 2012 ◽  
pp. 1-16 ◽  
Author(s):  
Kamonnaree Chotinantakul ◽  
Wilairat Leeanansaksiri
Keyword(s):  
Stem Cell ◽  
Signaling Pathways ◽  
Cell Biology ◽  
The Body ◽  
Basic Knowledge ◽  
Stem Cell Biology ◽  
Quiescent State ◽  
Hematopoietic Stem ◽  
Medicine Development ◽  
Biology Research

Hematopoietic stem cells (HSCs) play a key role in hematopoietic system that functions mainly in homeostasis and immune response. HSCs transplantation has been applied for the treatment of several diseases. However, HSCs persist in the small quantity within the body, mostly in the quiescent state. Understanding the basic knowledge of HSCs is useful for stem cell biology research and therapeutic medicine development. Thus, this paper emphasizes on HSC origin, source, development, the niche, and signaling pathways which support HSC maintenance and balance between self-renewal and proliferation which will be useful for the advancement of HSC expansion and transplantation in the future.

scholarly journals Mutations in CSPP1 Cause Primary Cilia Abnormalities and Joubert Syndrome with or without Jeune Asphyxiating Thoracic Dystrophy

2014 ◽  
Vol 94 (1) ◽  
pp. 62-72 ◽  
Author(s):  
Karina Tuz ◽  
Ruxandra Bachmann-Gagescu ◽  
Diana R. O’Day ◽  
Kiet Hua ◽  
Christine R. Isabella ◽  
...  
Keyword(s):  
Primary Cilia ◽  
Joubert Syndrome ◽  
Asphyxiating Thoracic Dystrophy ◽  
Thoracic Dystrophy

scholarly journals Prenatal alcohol exposure disrupts Shh pathway and primary cilia genes in the mouse neural tube

2019 ◽  
Author(s):  
Karen E. Boschen ◽  
Eric W. Fish ◽  
Scott E. Parnell
Keyword(s):  
Cell Cycle ◽  
Neural Tube ◽  
Primary Cilia ◽  
Alcohol Exposure ◽  
Brain Structures ◽  
Joubert Syndrome ◽  
Cell Cycle Gene ◽  
Layer Width ◽  
Shh Pathway ◽  
Prenatal Alcohol

AbstractNeurulation-stage alcohol exposure (NAE; embryonic day [E] 8-10) is associated with midline craniofacial and CNS defects that likely arise from disruption of morphogen pathways, such as Sonic hedgehog (Shh). Notably, midline anomalies are also a hallmark of genetic ciliopathies such as Joubert syndrome. We tested whether NAE alters Shh pathway signaling and the number and function of primary cilia, organelles critical for Shh pathway transduction. Female C57BL/6J mice were administered two doses of alcohol (2.9 g/kg/dose) or vehicle on E9. Embryos were collected 6, 12, or 24 hr later, and changes to Shh, cell cycle genes, and primary cilia were measured in the rostroventral neural tube (RVNT). Within the first 24 hours post-NAE, reductions in Shh pathway and cell cycle gene expression and the ratio of Gli3 forms in the full-length activator state were observed. RVNT volume and cell layer width were reduced at 12 hr. In addition, expression of multiple cilia-related genes were observed at 6 hr post-NAE. As a further test of cilia gene-ethanol interaction, mice heterozygous for Kif3a exhibited perturbed behavior during adolescence following NAE compared to vehicle-treated mice, and Kif3a heterozygosity exacerbated the hyperactive effects of NAE on exploratory activity. These data demonstrate that NAE downregulates the Shh pathway in a region of the neural tube that gives rise to alcohol-sensitive brain structures and identifies disruption of primary cilia function, or a “transient ciliopathy”, as a possible cellular mechanism of prenatal alcohol pathogenesis.

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