bims-bicyki 2022-09-11 papers

bims-bicyki

Biomed News

on Bicaudal-C1 and interactors in cystic kidney disease

Issue of 2022‒09‒11
twenty papers selected by
Céline Gagnieux
École Polytechnique Fédérale de Lausanne (EPFL)

[Analysis of PDK1 gene variants and prenatal diagnosis for eight pedigrees affected with autosomal dominant polycystic kidney disease].
Accuracy, Reproducibility and User Experience With Standardized Instructions for Measurement of Total Kidney Volume in Autosomal Dominant Polycystic Kidney Disease.
EV duty vehicles: Features and functions of ciliary extracellular vesicles.
Efficacy and safety of tolvaptan versus placebo in the treatment of patients with autosomal dominant polycystic kidney disease: a meta-analysis.
Cilia proteins getting to work - how do they commute from the cytoplasm to the base of cilia?
Primary cilium in kidney development, function and disease.
Evaluation of ciliary functions and ciliary beat frequency via cell culture method in patients with primary ciliary dyskinesia.
Mechanisms of Regulation in Intraflagellar Transport.
CEP19-RABL2-IFT-B axis controls BBSome-mediated ciliary GPCR export.
Multiple ciliary localization signals control INPP5E ciliary targeting.
Mutations in SCNM1 cause orofaciodigital syndrome due to minor intron splicing defects affecting primary cilia.
Heterogeneity of the NIH3T3 Fibroblast Cell Line.
Biallelic DAW1 variants cause a motile ciliopathy characterized by laterality defects and subtle ciliary beating abnormalities.
The evolutionary conserved proteins CEP90, FOPNL, and OFD1 recruit centriolar distal appendage proteins to initiate their assembly.
Carnitine Protects against MPP+-Induced Neurotoxicity and Inflammation by Promoting Primary Ciliogenesis in SH-SY5Y Cells.
Progress in diagnosis of primary ciliary dyskinesia.
Deletion of CEP164 in mouse photoreceptors post-ciliogenesis interrupts ciliary intraflagellar transport (IFT).
In vitro modeling and rescue of ciliopathy associated with IQCB1/NPHP5 mutations using patient-derived cells.
Otological Manifestations in Adults with Primary Ciliary Dyskinesia: A Controlled Radio-Clinical Study.
NIMA-related kinase-6 (NEK6) as an executable target in cancer.

Zhonghua Yi Xue Yi Chuan Xue Za Zhi. 2022 Sep 10. 39(9): 932-937

[Analysis of PDK1 gene variants and prenatal diagnosis for eight pedigrees affected with autosomal dominant polycystic kidney disease].

Huijun Li, Peixuan Cao, Xiangyu Zhu, Yujie Zhu, Xing Wu, Jie Li.

OBJECTIVE: To detect potential variants in eight Chinese pedigrees affected with autosomal dominant polycystic kidney disease (ADPKD) and provide prenatal diagnosis for two of them.METHODS: Whole exome sequencing and high-throughput sequencing were carried out to detect variants of PKD1 and PKD2 genes in the probands. Sanger sequencing was used to validate the variants, and their pathogenicity was predicted by searching the ADPKD and protein variation databases.
RESULTS: Eight PKD1 variants were detected, which have included five nonsense mutations and three missense mutations. Among these, four nonsense variants (PKD1: c.7555C>T, c.7288C>T, c.4957C>T, c.11423G>A) were known to be pathogenic, whilst one missense variant (PKD1: c.2180T>G) was classified as likely pathogenic. Three novel variants were detected, which included c.6781G>T (p.Glu2261*), c.109T>G (p.Cys37Gly) and c.8495A>G (p.Asn2832Ser). Prenatal testing showed that the fetus of one family has carried the same mutation as the proband, while the fetus of another family did not.
CONCLUSION: PKD1 variants, including three novel variants, have been identified in the eight pedigrees affected with ADPKD. Based on these results, prenatal diagnosis and genetic counseling have been provided.

DOI: https://doi.org/10.3760/cma.j.cn511374-20210715-00597
Can Assoc Radiol J. 2022 Sep 05. 8465371221124120

Accuracy, Reproducibility and User Experience With Standardized Instructions for Measurement of Total Kidney Volume in Autosomal Dominant Polycystic Kidney Disease.

Micheli Bevilacqua, Cameron J Hague, Alexandra Romann, Adeera Levin.

  PURPOSE: Total kidney volume (TKV) measurement is integral in clinical management of autosomal dominant polycystic kidney disease (ADPKD) but the gold standard of measurement via stereology/manual planimetry is time-consuming and not readily available to clinicians. This study assessed whether standardized measurement instructions based on an ellipsoid equation enhanced TKV assessment on computed tomographic (CT) images of the kidneys as determined by accuracy, reproducibility, efficiency and/or user acceptability.METHODS: Participating radiologists were randomized to perform TKV measurements with or without standardized instructions. All participants measured the same 3 non-contrast, low-dose CT scans. Accuracy was assessed as variation from TKV measurements obtained by planimetry. Intraclass correlation coefficients and time to complete the measurements were assessed. Surveys assessed prior experience with TKV measurement and user acceptability of the instructions.
RESULTS: 49 radiologists participated. There was no difference in accuracy or measurement time between instructed and non-instructed participants. There was a trend towards greater reproducibility with standardized instructions (ICC .8 vs .6). 92% of respondents indicated the instructions were easy to use, 86% agreed the instructions would enhance their comfort with TKV measurement and 75% agreed they would recommend these instructions to colleagues.
CONCLUSIONS: Instructed and non-instructed participants demonstrated similar accuracy and time required for TKV measurement, but instructed participants had a trend towards greater reproducibility. There was high acceptability including enhanced user confidence with the instructions. Standardized instructions may be of value for radiologists seeking to improve their confidence in providing clinicians with TKV measurements necessary to appropriately manage this patient population.

Keywords:  measurement instructions; polycystic kidney disease; renal volume; standardization; total kidney volume

DOI:  https://doi.org/10.1177/08465371221124120
Front Genet. 2022 ;13 916233

EV duty vehicles: Features and functions of ciliary extracellular vesicles.

Ludovic Vinay, Clémence Belleannée.

  The primary cilium is a microtubule-based organelle that extends from a basal body at the surface of most cells. This antenna is an efficient sensor of the cell micro-environment and is instrumental to the proper development and homeostatic control of organs. Recent compelling studies indicate that, in addition to its role as a sensor, the primary cilium also emits signals through the release of bioactive extracellular vesicles (EVs). While some primary-cilium derived EVs are released through an actin-dependent ectocytosis and are called ectosomes (or large EVs, 350-500 nm), others originate from the exocytosis of multivesicular bodies and are smaller (small EVs, 50-100 nm). Ciliary EVs carry unique signaling factors, including protein markers and microRNAs (miRNAs), and participate in intercellular communication in different organism models. This review discusses the mechanism of release, the molecular features, and functions of EVs deriving from cilia, based on the existing literature.

Keywords:  ciliary extracellular vesicles; ectocytosis; ectosomes; intercellular communication; markers; motile cilia; primary cilia

DOI:  https://doi.org/10.3389/fgene.2022.916233
Int Urol Nephrol. 2022 Sep 07.

Efficacy and safety of tolvaptan versus placebo in the treatment of patients with autosomal dominant polycystic kidney disease: a meta-analysis.

Jingkui Lu, Wei Xu, Lifeng Gong, Min Xu, Weigang Tang, Wei Jiang, Fengyan Xie, Liping Ding, Xiaoli Qian.

  OBJECTIVE: The objective of this meta-analysis was to compare the efficacy and drug safety of tolvaptan with placebo for autosomal dominant polycystic kidney disease (ADPKD).METHODS: The PubMed, Embase, and Cochrane Library databases were searched from inception to September 10, 2021. Eligible studies comparing tolvaptan and placebo in the treatment of patients with ADPKD were included. Data were analysed using Review Manager Version 5.3.
RESULTS: Thirteen studies involving 3575 patients were included in the meta-analysis. Compared with placebo, tolvaptan had a better effect on delaying eGFR decline (MD 1.27, 95% CI 1.24-1.29, P < 0.01) and TKV increase (MD - 3.01, 95% CI - 3.55 to - 2.47, P < 0.01) in ADPKD treatment. Additionally, tolvaptan reduced the incidence of complications such as renal pain (OR 0.71, 95% CI 0.58-0.87, P < 0.01), urinary tract infection (OR 0.69, 95% CI 0.54-0.89, P < 0.01), haematuria (OR 0.68, 95% CI 0.51-0.89, P < 0.01), and hypertension (OR 0.66, 95% CI 0.52-0.82, P < 0.01). However, tolvaptan was associated with a higher incidence rate of adverse events such as thirst (OR 8.48 95% CI 4.53-15.87, P < 0.01), polyuria (OR 4.71, 95% CI 2.17-10.24, P < 0.01), and hepatic injury (OR 4.56, 95% CI 2.51-8.29, P < 0.01).
CONCLUSION: Tolvaptan can delay eGFR decline and TKV increase and reduce complications such as renal pain, urinary tract infection, haematuria, and hypertension in the treatment of ADPKD. However, tolvaptan increases the adverse effects of thirst, polyuria and hepatic injury.

Keywords:  Autosomal dominant polycystic kidney disease; Meta-analysis; Placebo; Tolvaptan

DOI:  https://doi.org/10.1007/s11255-022-03353-8
J Cell Sci. 2022 Sep 01. pii: jcs259444. [Epub ahead of print]135(17):

Cilia proteins getting to work - how do they commute from the cytoplasm to the base of cilia?

Jaime V K Hibbard, Neftalí Vázquez, John B Wallingford.

  Cilia are multifunctional organelles that originated with the last eukaryotic common ancestor and play central roles in the life cycles of diverse organisms. The motile flagella that move single cells like sperm or unicellular organisms, the motile cilia on animal multiciliated cells that generate fluid flow in organs, and the immotile primary cilia that decorate nearly all cells in animals share many protein components in common, yet each also requires specialized proteins to perform their specialized functions. Despite a now-advanced understanding of how such proteins are transported within cilia, we still know very little about how they are transported from their sites of synthesis through the cytoplasm to the ciliary base. Here, we review the literature concerning this underappreciated topic in ciliary cell biology. We discuss both general mechanisms, as well as specific examples of motor-driven active transport and passive transport via diffusion-and-capture. We then provide deeper discussion of specific, illustrative examples, such as the diverse array of protein subunits that together comprise the intraflagellar transport (IFT) system and the multi-protein axonemal dynein motors that drive beating of motile cilia. We hope this Review will spur further work, shedding light not only on ciliogenesis and ciliary signaling, but also on intracellular transport in general.

Keywords:  Basal body; Centrosome; Cilia; Cytoplasmic transport; Diffusion; Motor proteins

DOI:  https://doi.org/10.1242/jcs.259444
Front Endocrinol (Lausanne). 2022 ;13 952055

Primary cilium in kidney development, function and disease.

Yunfeng Bai, Cuiting Wei, Ping Li, Xuefeng Sun, Guangyan Cai, Xiangmei Chen, Quan Hong.

  The primary cilium is a hair-like, microtubule-based organelle that is covered by the cell membrane and extends from the surface of most vertebrate cells. It detects and translates extracellular signals to direct various cellular signaling pathways to maintain homeostasis. It is mainly distributed in the proximal and distal tubules and collecting ducts in the kidney. Specific signaling transduction proteins localize to primary cilia. Defects in cilia structure and function lead to a class of diseases termed ciliopathies. The proper functioning of primary cilia is essential to kidney organogenesis and the maintenance of epithelial cell differentiation and proliferation. Persistent cilia dysfunction has a role in the early stages and progression of renal diseases, such as cystogenesis and acute tubular necrosis (ATN). In this review, we focus on the central role of cilia in kidney development and illustrate how defects in cilia are associated with renal disease progression.

Keywords:  ciliopathy; kidney development; primary cilium; renal disease; renal function

DOI:  https://doi.org/10.3389/fendo.2022.952055
Turk J Pediatr. 2022 ;pii: 2467. [Epub ahead of print]64(4): 612-618

Evaluation of ciliary functions and ciliary beat frequency via cell culture method in patients with primary ciliary dyskinesia.

Nagehan Emiralioğlu, Rümeysa Hekimoğlu, Bengisu Kaya, Elif Bilgiç, Pergin Atilla, Önder Günaydın, Gökçen Dilşa Tuğcu, Sanem Eryılmaz Polat, Mina Gharibzadeh Hızal, Ebru Yalçın, Deniz Doğru, Nural Kiper, Uğur Özçelik.

  BACKGROUND: Cell culture increases both diagnostic specificity and sensitivity of primary ciliary dyskinesia (PCD) and the most important reason to use cell culture for definitive diagnosis in PCD is to exclude secondary ciliary defects. Here we aimed to evaluate the cilia functions and cilia ultrastructural abnormalities after ciliogenesis of cell culture in patients with definitive diagnosis of PCD. We also aimed to compare high speed videomicroscopy (HSVM) results of patients before and after ciliogenesis and to compare them with electron microscopy, genetic and immunofluorescence results in patients with positive diagnosis of PCD.METHODS: This study was conducted as a cross-sectional study in patients with PCD. HSVM, transmission electron microscopy (TEM) and immunofluorescence staining results of the nasal biopsy samples taken from patients with the definitive diagnosis of PCD were evaluated and HSVM findings before and after cell culture were described.
RESULTS: Ciliogenesis and regrowth in the cell culture occurred in the nasal biopsy sample of eight patients with PCD. The mean age of the patients was 15.5±4.2 years (8.5-18 years). Mean beat frequency was found to be 7.54±1.01 hz (6.53-9.45 hz) before cell culture, and 7.36±0.86 hz (6.02-7.99 hz) after cell culture in the nasal biopsy of patients. There was no significant difference in the beat frequency of PCD patients before and after cell culture. Ciliary function analysis showed the similar beating pattern before and after cell culture in patients with PCD.
CONCLUSIONS: This study showed us that there was no difference between cilia beat frequency and beat pattern before and after cell culture in patients with definitive diagnosis of PCD and repeated HSVM would be a useful diagnostic approach in patients who have no possibility to reach other diagnostic methods.

Keywords:  cell culture; cilia function analysis; high speed videomicroscopy; primary ciliary dyskinesia

DOI:  https://doi.org/10.24953/turkjped.2020.3361
Cells. 2022 Sep 02. pii: 2737. [Epub ahead of print]11(17):

Mechanisms of Regulation in Intraflagellar Transport.

Wouter Mul, Aniruddha Mitra, Erwin J G Peterman.

  Cilia are eukaryotic organelles essential for movement, signaling or sensing. Primary cilia act as antennae to sense a cell's environment and are involved in a wide range of signaling pathways essential for development. Motile cilia drive cell locomotion or liquid flow around the cell. Proper functioning of both types of cilia requires a highly orchestrated bi-directional transport system, intraflagellar transport (IFT), which is driven by motor proteins, kinesin-2 and IFT dynein. In this review, we explore how IFT is regulated in cilia, focusing from three different perspectives on the issue. First, we reflect on how the motor track, the microtubule-based axoneme, affects IFT. Second, we focus on the motor proteins, considering the role motor action, cooperation and motor-train interaction plays in the regulation of IFT. Third, we discuss the role of kinases in the regulation of the motor proteins. Our goal is to provide mechanistic insights in IFT regulation in cilia and to suggest directions of future research.

Keywords:  axoneme; cilia; dynein; intraflagellar transport; kinesin; kinesin-2; microtubules; motor proteins; motor regulation

DOI:  https://doi.org/10.3390/cells11172737
Mol Biol Cell. 2022 Sep 08.

CEP19-RABL2-IFT-B axis controls BBSome-mediated ciliary GPCR export.

Zhuang Zhou, Yohei Katoh, Kazuhisa Nakayama.

The intraflagellar transport (IFT) machinery mediates the import and export of ciliary proteins across the ciliary gate, as well as bidirectional protein trafficking within cilia. In addition to ciliary anterograde protein trafficking, the IFT-B complex participates in the export of membrane proteins together with the BBSome, which consists of eight subunits encoded by the causative genes of Bardet-Biedl syndrome (BBS). The IFT25-IFT27/BBS19 dimer in the IFT-B complex constitutes its interface with the BBSome. We here show that IFT25-IFT27 and the RABL2 GTPase bind the IFT74/BBS22-IFT81 dimer of the IFT-B complex in a mutually exclusive manner. Cells expressing GTP-locked RABL2 [RABL2(Q80L)], but not wild-type RABL2, phenocopied IFT27-knockout cells, i.e., they demonstrated BBS-associated ciliary defects, including accumulation of LZTFL1/BBS17 and the BBSome within cilia, and the suppression of export of the ciliary GPCRs GPR161 and Smoothened. RABL2(Q80L) enters cilia in a manner dependent on the basal body protein CEP19, but its entry into cilia is not necessary for causing BBS-associated ciliary defects. These observations suggest that GTP-bound RABL2 is likely to be required for recruitment of the IFT-B complex to the ciliary base, where it is replaced with IFT25-IFT27.

DOI: https://doi.org/10.1091/mbc.E22-05-0161
Elife. 2022 09 05. pii: e78383. [Epub ahead of print]11

Multiple ciliary localization signals control INPP5E ciliary targeting.

Dario Cilleros-Rodriguez, Raquel Martin-Morales, Pablo Barbeito, Abhijit Deb Roy, Abdelhalim Loukil, Belen Sierra-Rodero, Gonzalo Herranz, Olatz Pampliega, Modesto Redrejo-Rodriguez, Sarah C Goetz, Manuel Izquierdo, Takanari Inoue, Francesc R Garcia-Gonzalo.

  Primary cilia are sensory membrane protrusions whose dysfunction causes ciliopathies. INPP5E is a ciliary phosphoinositide phosphatase mutated in ciliopathies like Joubert syndrome. INPP5E regulates numerous ciliary functions, but how it accumulates in cilia remains poorly understood. Herein, we show INPP5E ciliary targeting requires its folded catalytic domain and is controlled by four conserved ciliary localization signals (CLSs): LLxPIR motif (CLS1), W383 (CLS2), FDRxLYL motif (CLS3) and CaaX box (CLS4). We answer two long-standing questions in the field. First, partial CLS1-CLS4 redundancy explains why CLS4 is dispensable for ciliary targeting. Second, the essential need for CLS2 clarifies why CLS3-CLS4 are together insufficient for ciliary accumulation. Furthermore, we reveal that some Joubert syndrome mutations perturb INPP5E ciliary targeting, and clarify how each CLS works: (i) CLS4 recruits PDE6D, RPGR and ARL13B, (ii) CLS2-CLS3 regulate association to TULP3, ARL13B, and CEP164, and (iii) CLS1 and CLS4 cooperate in ATG16L1 binding. Altogether, we shed light on the mechanisms of INPP5E ciliary targeting, revealing a complexity without known parallels among ciliary cargoes.

Keywords:  INPP5E; Joubert syndrome; biochemistry; cell biology; chemical biology; cilia; ciliopathies; none; phosphatase; phosphoinositides

DOI:  https://doi.org/10.7554/eLife.78383
Am J Hum Genet. 2022 Sep 06. pii: S0002-9297(22)00361-5. [Epub ahead of print]

Mutations in SCNM1 cause orofaciodigital syndrome due to minor intron splicing defects affecting primary cilia.

Asier Iturrate, Ana Rivera-Barahona, Carmen-Lisset Flores, Ghada A Otaify, Rasha Elhossini, Marina L Perez-Sanz, Julián Nevado, Jair Tenorio-Castano, Juan Carlos Triviño, Francesc R Garcia-Gonzalo, Francesca Piceci-Sparascio, Alessandro De Luca, Leopoldo Martínez, Tugba Kalaycı, Pablo Lapunzina, Umut Altunoglu, Mona Aglan, Ebtesam Abdalla, Victor L Ruiz-Perez.

  Orofaciodigital syndrome (OFD) is a genetically heterogeneous ciliopathy characterized by anomalies of the oral cavity, face, and digits. We describe individuals with OFD from three unrelated families having bi-allelic loss-of-function variants in SCNM1 as the cause of their condition. SCNM1 encodes a protein recently shown to be a component of the human minor spliceosome. However, so far the effect of loss of SCNM1 function on human cells had not been assessed. Using a comparative transcriptome analysis between fibroblasts derived from an OFD-affected individual harboring SCNM1 mutations and control fibroblasts, we identified a set of genes with defective minor intron (U12) processing in the fibroblasts of the affected subject. These results were reproduced in SCNM1 knockout hTERT RPE-1 (RPE-1) cells engineered by CRISPR-Cas9-mediated editing and in SCNM1 siRNA-treated RPE-1 cultures. Notably, expression of TMEM107 and FAM92A encoding primary cilia and basal body proteins, respectively, and that of DERL2, ZC3H8, and C17orf75, were severely reduced in SCNM1-deficient cells. Primary fibroblasts containing SCNM1 mutations, as well as SCNM1 knockout and SCNM1 knockdown RPE-1 cells, were also found with abnormally elongated cilia. Conversely, cilia length and expression of SCNM1-regulated genes were restored in SCNM1-deficient fibroblasts following reintroduction of SCNM1 via retroviral delivery. Additionally, functional analysis in SCNM1-retrotransduced fibroblasts showed that SCNM1 is a positive mediator of Hedgehog (Hh) signaling. Our findings demonstrate that defective U12 intron splicing can lead to a typical ciliopathy such as OFD and reveal that primary cilia length and Hh signaling are regulated by the minor spliceosome through SCNM1 activity.

Keywords:  SCNM1; U12 introns; ciliopathy; hedgehog signaling; minor spliceosome; orofaciodigital syndrome; primary cilia

DOI:  https://doi.org/10.1016/j.ajhg.2022.08.009
Cells. 2022 Aug 28. pii: 2677. [Epub ahead of print]11(17):

Heterogeneity of the NIH3T3 Fibroblast Cell Line.

Amir Mohammad Rahimi, Mingfang Cai, Sigrid Hoyer-Fender.

  The embryonic mouse fibroblast cell line NIH3T3 is widely used in life science research, including the study of cell cycle control and primary cilia. Fibroblasts are the most important cell type in connective tissue, as they produce components of the extracellular matrix and determine tissue architecture. However, they are very heterogeneous and consist of subtypes specific to their organ of residence, among others. The NIH3T3 cell line was derived from whole mouse embryos that developed to pre-birth and is therefore most likely composed of different fibroblast subtypes. Furthermore, prolonged proliferation may have influenced their cellular composition. A heterogeneous cell population is unsuitable for any sophisticated research project. We found that the proportion of ciliated cells in the total NIH3T3 cell population was highly variable and asked whether this was a consequence of cellular heterogeneity and what molecular signatures were associated with it. We have established sub-cell lines by clonal expansion of single cells and characterized them morphologically and molecularly. Eventually, a myofibroblast-like and a fibroblast-like cell line were generated that differ in ciliation and proliferation. These homogeneous cell lines are valuable for a more detailed study of their molecular signatures, not least to uncover further the molecular pathways that contribute to the formation of the primary cilium.

Keywords:  NIH3T3; fibroblasts; myofibroblasts; primary cilia; proliferation

DOI:  https://doi.org/10.3390/cells11172677
Genet Med. 2022 Sep 07. pii: S1098-3600(22)00870-X. [Epub ahead of print]

Biallelic DAW1 variants cause a motile ciliopathy characterized by laterality defects and subtle ciliary beating abnormalities.

Joseph S Leslie, Rim Hjeij, Asaf Vivante, Elizabeth A Bearce, Laura Dyer, Jiaolong Wang, Lettie Rawlins, Joanna Kennedy, Nishanka Ubeyratna, James Fasham, Zoe H Irons, Samuel B Craig, Julia Koenig, Sebastian George, Ben Pode-Shakked, Yoav Bolkier, Ortal Barel, Shrikant Mane, Kathrine K Frederiksen, Olivia Wenger, Ethan Scott, Harold E Cross, Esben Lorentzen, Dominic P Norris, Yair Anikster, Heymut Omran, Daniel T Grimes, Andrew H Crosby, Emma L Baple.

  PURPOSE: The clinical spectrum of motile ciliopathies includes laterality defects, hydrocephalus, and infertility as well as primary ciliary dyskinesia when impaired mucociliary clearance results in otosinopulmonary disease. Importantly, approximately 30% of patients with primary ciliary dyskinesia lack a genetic diagnosis.METHODS: Clinical, genomic, biochemical, and functional studies were performed alongside in vivo modeling of DAW1 variants.
RESULTS: In this study, we identified biallelic DAW1 variants associated with laterality defects and respiratory symptoms compatible with motile cilia dysfunction. In early mouse embryos, we showed that Daw1 expression is limited to distal, motile ciliated cells of the node, consistent with a role in left-right patterning. daw1 mutant zebrafish exhibited reduced cilia motility and left-right patterning defects, including cardiac looping abnormalities. Importantly, these defects were rescued by wild-type, but not mutant daw1, gene expression. In addition, pathogenic DAW1 missense variants displayed reduced protein stability, whereas DAW1 loss-of-function was associated with distal type 2 outer dynein arm assembly defects involving axonemal respiratory cilia proteins, explaining the reduced cilia-induced fluid flow in particle tracking velocimetry experiments.
CONCLUSION: Our data define biallelic DAW1 variants as a cause of human motile ciliopathy and determine that the disease mechanism involves motile cilia dysfunction, explaining the ciliary beating defects observed in affected individuals.

Keywords:  DAW1; Heterotaxy; Left-right asymmetry; Motile cilia; Primary ciliary dyskinesia

DOI:  https://doi.org/10.1016/j.gim.2022.07.019
PLoS Biol. 2022 Sep 07. 20(9): e3001782

The evolutionary conserved proteins CEP90, FOPNL, and OFD1 recruit centriolar distal appendage proteins to initiate their assembly.

Pierrick Le Borgne, Logan Greibill, Marine Hélène Laporte, Michel Lemullois, Khaled Bouhouche, Mebarek Temagoult, Olivier Rosnet, Maeva Le Guennec, Laurent Lignières, Guillaume Chevreux, France Koll, Virginie Hamel, Paul Guichard, Anne-Marie Tassin.

In metazoa, cilia assembly is a cellular process that starts with centriole to basal body maturation, migration to the cell surface, and docking to the plasma membrane. Basal body docking involves the interaction of both the distal end of the basal body and the transition fibers/distal appendages, with the plasma membrane. Mutations in numerous genes involved in basal body docking and transition zone assembly are associated with the most severe ciliopathies, highlighting the importance of these events in cilium biogenesis. In this context, the ciliate Paramecium has been widely used as a model system to study basal body and cilia assembly. However, despite the evolutionary conservation of cilia assembly events across phyla, whether the same molecular players are functionally conserved, is not fully known. Here, we demonstrated that CEP90, FOPNL, and OFD1 are evolutionary conserved proteins crucial for ciliogenesis. Using ultrastructure expansion microscopy, we unveiled that these proteins localize at the distal end of both centrioles/basal bodies in Paramecium and mammalian cells. Moreover, we found that these proteins are recruited early during centriole duplication on the external surface of the procentriole. Functional analysis performed both in Paramecium and mammalian cells demonstrate the requirement of these proteins for distal appendage assembly and basal body docking. Finally, we show that mammalian centrioles require another component, Moonraker (MNR), to recruit OFD1, FOPNL, and CEP90, which will then recruit the distal appendage proteins CEP83, CEP89, and CEP164. Altogether, we propose that this OFD1, FOPNL, and CEP90 functional module is required to determine in mammalian cells the future position of distal appendage proteins.

DOI: https://doi.org/10.1371/journal.pbio.3001782
Cells. 2022 Sep 01. pii: 2722. [Epub ahead of print]11(17):

Carnitine Protects against MPP+-Induced Neurotoxicity and Inflammation by Promoting Primary Ciliogenesis in SH-SY5Y Cells.

Ji-Eun Bae, Joon Bum Kim, Doo Sin Jo, Na Yeon Park, Yong Hwan Kim, Ha Jung Lee, Seong Hyun Kim, So Hyun Kim, Mikyung Son, Pansoo Kim, Hong-Yeoul Ryu, Won Ha Lee, Zae Young Ryoo, Hyun-Shik Lee, Yong-Keun Jung, Dong-Hyung Cho.

  Primary cilia help to maintain cellular homeostasis by sensing conditions in the extracellular environment, including growth factors, nutrients, and hormones that are involved in various signaling pathways. Recently, we have shown that enhanced primary ciliogenesis in dopamine neurons promotes neuronal survival in a Parkinson's disease model. Moreover, we performed fecal metabolite screening in order to identify several candidates for improving primary ciliogenesis, including L-carnitine and acetyl-L-carnitine. However, the role of carnitine in primary ciliogenesis has remained unclear. In addition, the relationship between primary cilia and neurodegenerative diseases has remained unclear. In this study, we have evaluated the effects of carnitine on primary ciliogenesis in 1-methyl-4-phenylpyridinium ion (MPP+)-treated cells. We found that both L-carnitine and acetyl-L-carnitine promoted primary ciliogenesis in SH-SY5Y cells. In addition, the enhancement of ciliogenesis by carnitine suppressed MPP+-induced mitochondrial reactive oxygen species overproduction and mitochondrial fragmentation in SH-SY5Y cells. Moreover, carnitine inhibited the production of pro-inflammatory cytokines in MPP+-treated SH-SY5Y cells. Taken together, our findings suggest that enhanced ciliogenesis regulates MPP+-induced neurotoxicity and inflammation.

Keywords:  L-carnitine; MPP+; Mitochondria; SH-SY5Y cells; acetyl-L-carnitine; primary cilia

DOI:  https://doi.org/10.3390/cells11172722
J Paediatr Child Health. 2022 Sep 07.

Progress in diagnosis of primary ciliary dyskinesia.

Shuna Wei, Haojun Xie, Yuanxiong Cheng.

  Primary ciliary dyskinesia (PCD) is an autosomal recessive genetic disorder characterised by motor ciliary dysfunction. The main manifestations are bronchiectasis, chronic sinusitis and situs inversus (viscera translocation triad). Additionally, it can present as male infertility and female ectopic pregnancy. However, there is currently no recognised diagnostic standard for PCD, which brings great challenges to its diagnosis and treatment. In addition to clinical data, the current diagnostic methods of PCD mainly include PICADAR, nasal exhaled nitric oxide, transmission electron microscopy, high-resolution immunofluorescence, high-speed video microscopy analysis and gene detection. This article makes a comprehensive comparison of the above diagnostic methods and suggests that genetic detection technology will become the general trend of PCD diagnosis.

Keywords:  gene therapy; immunofluorescence; nasal exhaled nitric oxide; primary ciliary dyskinesia; transmission electron microscopy

DOI:  https://doi.org/10.1111/jpc.16196
PLoS Genet. 2022 Sep 08. 18(9): e1010154

Deletion of CEP164 in mouse photoreceptors post-ciliogenesis interrupts ciliary intraflagellar transport (IFT).

Michelle Reed, Ken-Ichi Takemaru, Guoxin Ying, Jeanne M Frederick, Wolfgang Baehr.

Centrosomal protein of 164 kDa (CEP164) is located at distal appendages of primary cilia and is necessary for basal body (BB) docking to the apical membrane. To investigate the function of photoreceptor CEP164 before and after BB docking, we deleted CEP164 during retina embryonic development (Six3Cre), in postnatal rod photoreceptors (iCre75) and in mature retina using tamoxifen induction (Prom1-ETCre). BBs dock to the cell cortex during postnatal day 6 (P6) to extend a connecting cilium (CC) and an axoneme. P6 retina-specific knockouts (retCep164-/-) are unable to dock BBs, thereby preventing formation of CC or outer segments (OSs). In rod-specific knockouts (rodCep164-/-), Cre expression starts after P7 and CC/OS form. P16 rodCep164-/- rods have nearly normal OS lengths, and maintain OS attachment through P21 despite loss of CEP164. Intraflagellar transport components (IFT88, IFT57 and IFT140) were reduced at P16 rodCep164-/- BBs and CC tips and nearly absent at P21, indicating impaired intraflagellar transport. Nascent OS discs, labeled with a fluorescent dye on P14 and P18 and harvested on P19, showed continued rodCep164-/- disc morphogenesis but absence of P14 discs mid-distally, indicating OS instability. Tamoxifen induction with PROM1ETCre;Cep164F/F (tamCep164-/-) adult mice affected maintenance of both rod and cone OSs. The results suggest that CEP164 is key towards recruitment and stabilization of IFT-B particles at the BB/CC. IFT impairment may be the main driver of ciliary malfunction observed with hypomorphic CEP164 mutations.

DOI: https://doi.org/10.1371/journal.pgen.1010154
Stem Cell Reports. 2022 Aug 27. pii: S2213-6711(22)00415-5. [Epub ahead of print]

In vitro modeling and rescue of ciliopathy associated with IQCB1/NPHP5 mutations using patient-derived cells.

Kamil Kruczek, Zepeng Qu, Emily Welby, Hiroko Shimada, Suja Hiriyanna, Milton A English, Wadih M Zein, Brian P Brooks, Anand Swaroop.

  Mutations in the IQ calmodulin-binding motif containing B1 (IQCB1)/NPHP5 gene encoding the ciliary protein nephrocystin 5 cause early-onset blinding disease Leber congenital amaurosis (LCA), together with kidney dysfunction in Senior-Løken syndrome. For in vitro disease modeling, we obtained dermal fibroblasts from patients with NPHP5-LCA that were reprogrammed into induced pluripotent stem cells (iPSCs) and differentiated into retinal pigment epithelium (RPE) and retinal organoids. Patient fibroblasts and RPE demonstrated aberrantly elongated ciliary axonemes. Organoids revealed impaired development of outer segment structures, which are modified primary cilia, and mislocalization of visual pigments to photoreceptor cell soma. All patient-derived cells showed reduced levels of CEP290 protein, a critical cilia transition zone component interacting with NPHP5, providing a plausible mechanism for aberrant ciliary gating and cargo transport. Disease phenotype in NPHP5-LCA retinal organoids could be rescued by adeno-associated virus (AAV)-mediated IQCB1/NPHP5 gene augmentation therapy. Our studies thus establish a human disease model and a path for treatment of NPHP5-LCA.

Keywords:  Leber congenital amaurosis; RPE; Senior-Løken syndrome; gene therapy; patient-derived iPSC; photoreceptor; primary cilia; retinal organoids; stem cells; vision

DOI:  https://doi.org/10.1016/j.stemcr.2022.08.006
J Clin Med. 2022 Aug 31. pii: 5163. [Epub ahead of print]11(17):

Otological Manifestations in Adults with Primary Ciliary Dyskinesia: A Controlled Radio-Clinical Study.

Mihaela Alexandru, Paul de Boissieu, Farida Benoudiba, Malik Moustarhfir, Sookyung Kim, Émilie Bequignon, Isabelle Honoré, Gilles Garcia, Rana Mitri-Frangieh, Marie Legendre, Bruno Crestani, Camille Taillé, Estelle Escudier, Bernard Maitre, Jean-François Papon, Jérôme Nevoux.

  Primary ciliary dyskinesia (PCD) is a rare genetical disease characterized by an abnormal structure or function of the cilia, causing sinusitis, otitis, and bronchiectasis. Hearing loss affects 60% of PCD patients, but data are lacking concerning hearing and temporal bone imaging in adults. Our aim was to describe clinical and radiological ear disease in adults with genetically confirmed PCD. Data were recorded from January 2018 to December 2019. PCD patients were compared with controls with bronchiectasis without PCD. Clinical examination included otomicroscopy and auditory tests. A temporal bone CT scan (TBCT) was systematically performed. Seventeen patients (34 ears) were included in each group. The eardrums were abnormal in 25 (74%) PCD ears versus 8 (24%) ears in the controls (p < 0.05). Conductive hearing loss was more frequent in the PCD group (24% vs. 12% in controls). TBCT were abnormal in 94% PCD patients vs. 32% in the controls (p < 0.05). The Main CT-scan images in PCD were middle ear inflammation (65%), mastoid condensation (62%), or ossicular anomalies (35%). With its excellent sensitivity, TBCT gives typical arguments for PCD diagnosis, adding otological signs to the usual sinus CT signs (hypoplasia, aplasia). Systematic TBCT could be useful in the initial evaluation of patients with suspicion of PCD.

Keywords:  chronic otitis media; hearing loss; otitis media with effusion; primary ciliary dyskinesia; temporal bone CT scan

DOI:  https://doi.org/10.3390/jcm11175163
Clin Transl Oncol. 2022 Sep 08.

NIMA-related kinase-6 (NEK6) as an executable target in cancer.

Nagesh Kishan Panchal, Shruti Mohanty, Sabina Evan Prince.

  Cancer is a disease that develops when cells begin to divide uncontrollably and spreads to other parts of the body. Proliferation and invasion of cancerous cells are generally known to be influenced by cell cycle-related proteins in human malignancies. Therefore, in this review, we have emphasized on the serine/threonine kinase named NEK6. NEK6 is been deliberated to play a critical role in mitosis progression that includes mitotic spindle formation, metaphase to anaphase transition, and centrosome separation. Moreover, it has a mechanistic role in DNA repair and can cause apoptosis when inhibited. Past studies have connected NEK6 protein expression to cancer cell senescence. Besides, there are reports relating NEK6 to a range of malignancies including breast, lung, ovarian, prostate, kidney, liver, and others. Given its significance, this review attempts to describe the structural and functional aspects of NEK6 in various cellular processes, as well as how it is linked to different forms of cancer. Lastly, we have accentuated, on some of the plausible inhibitors that have been explored against NEK6 overexpression.

Keywords:  Apoptosis; Cell cycle; DNA repair; Hepatocellular carcinoma; NIMA kinases

DOI:  https://doi.org/10.1007/s12094-022-02926-4