scholarly journals Role of Primary Cilia in Odontogenesis

2017 ◽  
Vol 96 (9) ◽  
pp. 965-974 ◽  
Author(s):  
M. Hampl ◽  
P. Cela ◽  
H.L. Szabo-Rogers ◽  
M. Kunova Bosakova ◽  
H. Dosedelova ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Primary Cilium ◽  
Mammalian Cells ◽  
Primary Cilia ◽  
Tooth Development ◽  
Critical Role ◽  
Current Evidence ◽  
Developmental Defects ◽  
Dental Tissues ◽  
The Impact

Primary cilium is a solitary organelle that emanates from the surface of most postmitotic mammalian cells and serves as a sensory organelle, transmitting the mechanical and chemical cues to the cell. Primary cilia are key coordinators of various signaling pathways during development and maintenance of tissue homeostasis. The emerging evidence implicates primary cilia function in tooth development. Primary cilia are located in the dental epithelium and mesenchyme at early stages of tooth development and later during cell differentiation and production of hard tissues. The cilia are present when interactions between both the epithelium and mesenchyme are required for normal morphogenesis. As the primary cilium coordinates several signaling pathways essential for odontogenesis, ciliary defects can interrupt the latter process. Genetic or experimental alterations of cilia function lead to various developmental defects, including supernumerary or missing teeth, enamel and dentin hypoplasia, or teeth crowding. Moreover, dental phenotypes are observed in ciliopathies, including Bardet-Biedl syndrome, Ellis-van Creveld syndrome, Weyers acrofacial dysostosis, cranioectodermal dysplasia, and oral-facial-digital syndrome, altogether demonstrating that primary cilia play a critical role in regulation of both the early odontogenesis and later differentiation of hard tissue–producing cells. Here, we summarize the current evidence for the localization of primary cilia in dental tissues and the impact of disrupted cilia signaling on tooth development in ciliopathies.

Role of Primary Cilia in Bone and Cartilage

2021 ◽  
pp. 002203452110466
Author(s):  
Z. Chinipardaz ◽  
M. Liu ◽  
D.T. Graves ◽  
S. Yang
Keyword(s):  
Growth Factor ◽  
Bone Formation ◽  
Primary Cilium ◽  
Primary Cilia ◽  
Transforming Growth Factor ◽  
Tooth Development ◽  
Critical Role ◽  
Intraflagellar Transport ◽  
Growth Factor Signaling ◽  
Cilia Formation

The primary cilium is a nonmotile microtubule-based organelle in most vertebrate cell types. The primary cilium plays a critical role in tissue development and homeostasis by sensing and transducing various signaling pathways. Ciliary proteins such as intraflagellar transport (IFT) proteins as well as ciliary motor proteins, kinesin and dynein, comprise a bidirectional intraflagellar transport system needed for cilia formation and function. Mutations in ciliary proteins that lead to loss or dysfunction of primary cilia cause ciliopathies such as Jeune syndrome and Ellis–van Creveld syndrome and cause abnormalities in tooth development. These diseases exhibit severe skeletal and craniofacial dysplasia, highlighting the significance of primary cilia in skeletal development. Cilia are necessary for the propagation of hedgehog, transforming growth factor β, platelet-derived growth factor, and fibroblast growth factor signaling during osteogenesis and chondrogenesis. Ablation of ciliary proteins such as IFT80 or IFT20 blocks cilia formation, which inhibits osteoblast differentiation, osteoblast polarity, and alignment and reduces bone formation. Similarly, cilia facilitate chondrocyte differentiation and production of a cartilage matrix. Cilia also play a key role in mechanosensing and are needed for increased bone formation in response to mechanical forces.

scholarly journals Signaling pathways in intestinal homeostasis and colorectal cancer: KRAS at centre stage

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Camille Ternet ◽  
Christina Kiel
Keyword(s):  
Colorectal Cancer ◽  
Signaling Pathways ◽  
Intestinal Microbiota ◽  
Critical Role ◽  
Neuroendocrine Cells ◽  
Cell Junction ◽  
Intestinal Cell ◽  
Intestinal Homeostasis ◽  
Cell Functions ◽  
The Impact

AbstractThe intestinal epithelium acts as a physical barrier that separates the intestinal microbiota from the host and is critical for preserving intestinal homeostasis. The barrier is formed by tightly linked intestinal epithelial cells (IECs) (i.e. enterocytes, goblet cells, neuroendocrine cells, tuft cells, Paneth cells, and M cells), which constantly self-renew and shed. IECs also communicate with microbiota, coordinate innate and adaptive effector cell functions. In this review, we summarize the signaling pathways contributing to intestinal cell fates and homeostasis functions. We focus especially on intestinal stem cell proliferation, cell junction formation, remodelling, hypoxia, the impact of intestinal microbiota, the immune system, inflammation, and metabolism. Recognizing the critical role of KRAS mutants in colorectal cancer, we highlight the connections of KRAS signaling pathways in coordinating these functions. Furthermore, we review the impact of KRAS colorectal cancer mutants on pathway rewiring associated with disruption and dysfunction of the normal intestinal homeostasis. Given that KRAS is still considered undruggable and the development of treatments that directly target KRAS are unlikely, we discuss the suitability of targeting pathways downstream of KRAS as well as alterations of cell extrinsic/microenvironmental factors as possible targets for modulating signaling pathways in colorectal cancer.

scholarly journals The retromer complex regulates C. elegans development and mammalian ciliogenesis

2021 ◽  
Author(s):  
Shuwei Xie ◽  
Ellie Smith ◽  
Carter Dierlam ◽  
Danita Mathew ◽  
Angelina Davis ◽  
...  
Keyword(s):  
Potential Function ◽  
Primary Cilium ◽  
Mammalian Cells ◽  
Primary Cilia ◽  
Vulval Development ◽  
Sorting Nexin ◽  
Capping Protein ◽  
C Elegans ◽  
Retromer Complex ◽  
Mother Centriole

The mammalian retromer is comprised of subunits VPS26, VPS29 and VPS35, and a more loosely-associated sorting nexin (SNX) heterodimer. Despite known roles for the retromer in multiple trafficking events in yeast and mammalian cells, its role in development is poorly understood, and its potential function in primary ciliogenesis remains unknown. Using CRISPR-Cas9 editing, we demonstrated that vps-26 homozygous knockout C. elegans have reduced brood sizes and impaired vulval development, as well as decreased body length which has been linked to defects in primary ciliogenesis. Since many endocytic proteins are implicated in the generation of primary cilia, we addressed whether the retromer regulates ciliogenesis in mammalian cells. We observed VPS35 localized to the primary cilium, and depletion of VPS26, VPS35 or SNX1/SNX5 led to decreased ciliogenesis. Retromer also coimmunoprecipitated with the capping protein, CP110, and was required for its removal from the mother centriole. Herein, we characterize new roles for the retromer in C. elegans development and in the regulation of ciliogenesis in mammalian cells, and suggest a novel role for the retromer in CP110 removal from the mother centriole.

scholarly journals Current understandings of the relationship between extracellular vesicles and cilia

2020 ◽  
Author(s):  
Koji Ikegami ◽  
Faryal Ijaz
Keyword(s):  
Extracellular Vesicles ◽  
Primary Cilium ◽  
Mammalian Cells ◽  
Primary Cilia ◽  
Research Field ◽  
Historical Background ◽  
Unicellular Organism ◽  
The Relationship

Abstract Mammalian cells have a tiny hair-like protrusion on their surface called a primary cilium. Primary cilia are thought to be the antennae for the cells, receiving signals from the environment. In some studies, extracellular vesicles (EVs) were found attached to the surface of the primary cilium. An idea for the phenomenon is that the primary cilium is the receptor for receiving the EVs. Meanwhile, a unicellular organism, Chlamydomonas, which has two long cilia, usually called flagella, release EVs termed ectosomes from the surface of the flagella. Accumulating evidence suggests that the primary cilium also functions as the ‘emitter’ of EVs. Physiological and pathological impacts are also elucidated for the release of EVs from primary cilia. However, the roles of released cilia-derived EVs remain to be clarified. This review introduces the historical background of the relationship between EVs and cilia, and recent progresses in the research field.

scholarly journals Signaling Pathways Critical for Tooth Root Formation

2017 ◽  
Vol 96 (11) ◽  
pp. 1221-1228 ◽  
Author(s):  
J. Wang ◽  
J.Q. Feng
Keyword(s):  
Signaling Pathways ◽  
Root Formation ◽  
Root Resorption ◽  
Tooth Development ◽  
Critical Role ◽  
Future Research ◽  
Tooth Root ◽  
Short Root ◽  
Dentin Formation

Tooth is made of an enamel-covered crown and a cementum-covered root. Studies on crown dentin formation have been a major focus in tooth development for several decades. Interestingly, the population prevalence for genetic short root anomaly (SRA) with no apparent defects in crown is close to 1.3%. Furthermore, people with SRA itself are predisposed to root resorption during orthodontic treatment. The discovery of the unique role of Nfic (nuclear factor I C; a transcriptional factor) in controlling root but not crown dentin formation points to a new concept: tooth crown and root have different control mechanisms. Further genetic mechanism studies have identified more key molecules (including Osterix, β-catenin, and sonic hedgehog) that play a critical role in root formation. Extensive studies have also revealed the critical role of Hertwig’s epithelial root sheath in tooth root formation. In addition, Wnt10a has recently been found to be linked to multirooted tooth furcation formation. These exciting findings not only fill the critical gaps in our understanding about tooth root formation but will aid future research regarding the identifying factors controlling tooth root size and the generation of a whole “bio-tooth” for therapeutic purposes. This review starts with human SRA and mainly focuses on recent progress on the roles of NFIC-dependent and NFIC-independent signaling pathways in tooth root formation. Finally, this review includes a list of the various Cre transgenic mouse lines used to achieve tooth root formation–related gene deletion or overexpression, as well as strengths and limitations of each line.

scholarly journals The β-cell primary cilium is an autonomous Ca2+ compartment for paracrine GABA signalling

2021 ◽  
Author(s):  
Gonzalo Sanchez ◽  
Tugce Ceren Incedal ◽  
Juan Prada Salcedo ◽  
Paul O'Callaghan ◽  
Santiago Echeverry ◽  
...  
Keyword(s):  
Primary Cilium ◽  
Mammalian Cells ◽  
Primary Cilia ◽  
Β Cells ◽  
Intact Mouse ◽  
B1 Receptors ◽  
Pancreatic Islets Of Langerhans ◽  
Mouse Pancreatic Islets ◽  
Concentration Changes ◽  
Dependent Transport

The primary cilium is an organelle present in most adult mammalian cells and is thought of as an antenna for detection of a variety of signals. Here we use intact mouse pancreatic islets of Langerhans to investigate signalling properties of the primary cilium in β-cells. Using cilia-targeted Ca2+ indicators we find that the resting Ca2+ concentration in the cilium is lower than that of the cytosol, and we uncover a Ca2+ extrusion mechanism in the cilium that effectively insulates the cilium from changes in cytosolic Ca2+. Stimuli that give rise to pronounced cytosolic Ca2+ concentration increases, such as glucose- and depolarization-induced Ca2+ influx, and mobilization of Ca2+ from the ER, was accompanied by minor increases in cilia Ca2+ concentrations that were spatially restricted to a small compartment at the base. Conversely, we observe pronounced Ca2+ concentration changes in the primary cilia of islet β-cells that do not propagate into the cytosol and show that paracrine GABA signalling via cilia-localized GABA- B1-receptors is responsible for this Ca2+ signalling. Finally, we demonstrate that the cilia response to GABA involves ligand-dependent transport of GABA-B1 receptors into the cilium.

scholarly journals Exploring the Spectrum of Kidney Ciliopathies

Diagnostics ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1099
Author(s):  
Matteo Santoni ◽  
Francesco Piva ◽  
Alessia Cimadamore ◽  
Matteo Giulietti ◽  
Nicola Battelli ◽  
...  
Keyword(s):  
Kidney Disease ◽  
Signaling Pathways ◽  
Polycystic Kidney Disease ◽  
Primary Cilium ◽  
Primary Cilia ◽  
Kidney Diseases ◽  
Ubiquitin Proteasome System ◽  
Polycystic Kidney ◽  
Ubiquitin Proteasome ◽  
Autosomal Dominant Polycystic Kidney

Ciliopathies are a group of multi-organ diseases caused by the disruption of the primary cilium. This event leads to a variety of kidney disorders, including nephronophthisis, renal cystic dysplasia, and renal cell carcinoma (RCC). Primary cilium contributes to the regulation of the cell cycle and protein homeostasis, that is, the balance between protein synthesis and degradation by acting on the ubiquitin-proteasome system, autophagy, and mTOR signaling. Many proteins are involved in renal ciliopathies. In particular, fibrocystin (PKHD1) is involved in autosomal recessive polycystic kidney disease (ARPKD), while polycystin-1 (PKD1) and polycystin-2 (PKD2) are implicated in autosomal dominant polycystic kidney disease (ADPKD). Moreover, primary cilia are associated with essential signaling pathways, such as Hedgehog, Wnt, and Platelet-Derived Growth Factor (PDGF). In this review, we focused on the ciliopathies associated with kidney diseases, exploring genes and signaling pathways associated with primary cilium and the potential role of cilia as therapeutic targets in renal disorders.

scholarly journals Primary Cilium Is Involved in Stem Cell Differentiation and Renewal through the Regulation of Multiple Signaling Pathways

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1428
Author(s):  
Sila Yanardag ◽  
Elena N. Pugacheva
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Differentiation ◽  
Signaling Pathways ◽  
Primary Cilium ◽  
Primary Cilia ◽  
Vision Loss ◽  
Stem Cell Differentiation ◽  
Future Research ◽  
Renal Anomalies

Signaling networks guide stem cells during their lineage specification and terminal differentiation. Primary cilium, an antenna-like protrusion, directly or indirectly plays a significant role in this guidance. All stem cells characterized so far have primary cilia. They serve as entry- or check-points for various signaling events by controlling the signal transduction and stability. Thus, defects in the primary cilia formation or dynamics cause developmental and health problems, including but not limited to obesity, cardiovascular and renal anomalies, hearing and vision loss, and even cancers. In this review, we focus on the recent findings of how primary cilium controls various signaling pathways during stem cell differentiation and identify potential gaps in the field for future research.

scholarly journals Teasing out function from morphology: Similarities between primary cilia and immune synapses

2021 ◽  
Vol 220 (6) ◽  
Author(s):  
Tiphaine Douanne ◽  
Jane C. Stinchcombe ◽  
Gillian M. Griffiths
Keyword(s):  
Primary Cilium ◽  
Immune Cells ◽  
Primary Cilia ◽  
Molecular Mechanisms ◽  
Critical Role ◽  
Molecular Techniques ◽  
Immune Synapse ◽  
Polarized Secretion ◽  
Immune Synapses ◽  
Shed Light

Immune synapses are formed between immune cells to facilitate communication and coordinate the immune response. The reorganization of receptors involved in recognition and signaling creates a transient area of plasma membrane specialized in signaling and polarized secretion. Studies on the formation of the immune synapse between cytotoxic T lymphocytes (CTLs) and their targets uncovered a critical role for centrosome polarization in CTL function and suggested a striking parallel between the synapse and primary cilium. Since these initial observations, a plethora of further morphological, functional, and molecular similarities have been identified between these two fascinating structures. In this review, we describe how advances in imaging and molecular techniques have revealed additional parallels as well as functionally significant differences and discuss how comparative studies continue to shed light on the molecular mechanisms underlying the functions of both the immune synapse and primary cilium.

scholarly journals A proteomics approach for the identification of cullin-9 (CUL9) related signaling pathways in induced pluripotent stem cell models

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248000
Author(s):  
Natalya A. Ortolano ◽  
Alejandra I. Romero-Morales ◽  
Megan L. Rasmussen ◽  
Caroline Bodnya ◽  
Leigh A. Kline ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Signaling Pathways ◽  
Cell Cycle Progression ◽  
Critical Role ◽  
Induced Pluripotent Stem Cell ◽  
Cell Types ◽  
Current Evidence ◽  
Compensatory Mechanisms ◽  
Atp Production

CUL9 is a non-canonical and poorly characterized member of the largest family of E3 ubiquitin ligases known as the Cullin RING ligases (CRLs). Most CRLs play a critical role in developmental processes, however, the role of CUL9 in neuronal development remains elusive. We determined that deletion or depletion of CUL9 protein causes aberrant formation of neural rosettes, an in vitro model of early neuralization. In this study, we applied mass spectrometric approaches in human pluripotent stem cells (hPSCs) and neural progenitor cells (hNPCs) to identify CUL9 related signaling pathways that may contribute to this phenotype. Through LC-MS/MS analysis of immunoprecipitated endogenous CUL9, we identified several subunits of the APC/C, a major cell cycle regulator, as potential CUL9 interacting proteins. Knockdown of the APC/C adapter protein FZR1 resulted in a significant increase in CUL9 protein levels, however, CUL9 does not appear to affect protein abundance of APC/C subunits and adapters or alter cell cycle progression. Quantitative proteomic analysis of CUL9 KO hPSCs and hNPCs identified protein networks related to metabolic, ubiquitin degradation, and transcriptional regulation pathways that are disrupted by CUL9 deletion in both hPSCs. No significant changes in oxygen consumption rates or ATP production were detected in either cell type. The results of our study build on current evidence that CUL9 may have unique functions in different cell types and that compensatory mechanisms may contribute to the difficulty of identifying CUL9 substrates.

Sign in / Sign up

Export Citation Format

Share Document