A range of 30-62% of functioning multiciliated airway cells is sufficient to maintain ciliary airway clearance

BACKGROUND

Primary ciliary dyskinesia is a genetic disorder caused by aberrant motile cilia function that results in defective ciliary airway clearance and subsequently leads to recurrent airway infections and bronchiectasis. We aimed to determine: how many functional multiciliated airway cells are sufficient to maintain ciliary airway clearance?

METHODS

To answer this question we exploited the molecular defects of the X-linked recessive primary ciliary dyskinesia variant caused by pathogenic variants in DNAAF6 (PIH1D3), characterised by immotile cilia in affected males. We carefully analysed the clinical phenotype and molecular defect (using immunofluorescence and transmission electron microscopy) and performed in vitro studies (particle tracking in air-liquid interface cultures) and in vivo studies (radiolabelled tracer studies) to assess ciliary clearance of respiratory cells from female individuals with heterozygous and male individuals with hemizygous pathogenic DNAAF6 variants.

RESULTS

Primary ciliary dyskinesia male individuals with hemizygous pathogenic DNAAF6 variants displayed exclusively immotile cilia, absence of ciliary clearance and severe primary ciliary dyskinesia symptoms. Owing to random or skewed X-chromosome inactivation in six female carriers with heterozygous pathogenic DNAAF6 variants, 54.3±10% (range 38-70%) of multiciliated cells were defective. Nevertheless, in vitro and in vivo assessment of the ciliary airway clearance was normal or slightly abnormal. Consistently, heterozygous female individuals showed no or only mild respiratory symptoms.

CONCLUSIONS

Our findings indicate that having 30-62% of multiciliated respiratory cells functioning can generate either normal or slightly reduced ciliary clearance. Because heterozygous female carriers displayed either no or subtle respiratory symptoms, complete correction of 30% of cells by precision medicine could improve ciliary airway clearance in individuals with primary ciliary dyskinesia, as well as clinical symptoms.

Infertility and pregnancy outcomes among adults with primary ciliary dyskinesia

STUDY QUESTION

What is the prevalence of infertility and ectopic pregnancies among individuals with primary ciliary dyskinesia (PCD)?

SUMMARY ANSWER

We found that 39 of 50 men (78%) and 72 of 118 women (61%) with PCD were infertile and that women with PCD had an increased risk of ectopic pregnancies (7.6 per 100 pregnancies, 95% CI 4.7-12.2).

WHAT IS KNOWN ALREADY

PCD is a heterogeneous multiorgan disease caused by mutations in genes required for the function and structure of motile cilia. Previous studies identified a link between PCD and infertility, but original data on prevalence of infertility and risk of ectopic pregnancies, the use and efficacy of medically assisted reproduction (MAR), and the association of fertility with PCD genotype are extremely limited.

STUDY DESIGN SIZE DURATION

We performed a cross-sectional survey about fertility within the Living with PCD study (formerly COVID-PCD). Living with PCD is an international, online, participatory study that collects information directly from people with PCD. People with PCD of any age from anywhere in the world can participate in the study. At the time of the survey, 482 adults with PCD were registered within the Living with PCD study.

PARTICIPANTS/MATERIALS SETTING METHODS

We sent a questionnaire on fertility on 12 July 2022, to all participants older than 18 years enrolled in the Living with PCD study. Responses were collected until 8 March 2023. The fertility questionnaire covered topics related to pregnancy attempts, use of MAR, and pregnancy outcomes. Data were collected via the Research Electronic Data Capture (REDCap) platform. We defined infertility as failure to achieve a clinical pregnancy after 12 months or use of MAR for at least one pregnancy.

MAIN RESULTS AND THE ROLE OF CHANCE

In total, 265 of 482 adult participants (55%) completed the fertility questionnaire. Among 168 adults who had tried to conceive, 39 of 50 men (78%) and 72 of 118 women (61%) were infertile. Of the infertile men, 28 had tried MAR, and 17 of them (61%) fathered a child with the help of MAR. Among infertile women, 59 had used MAR, and 41 of them (69%) became pregnant with the help of MAR. In our population, women with PCD showed a relatively high risk of ectopic pregnancies: 1 in 10 women who became pregnant had at least one ectopic pregnancy and 7.6% of pregnancies were ectopic (95% CI 4.7-12.2). We evaluated the association between fertility and affected PCD genes in 46 individuals (11 men, 35 women) with available genetic and fertility information, and found differences between genotypes, e.g. all five women with a mutation in CCDC40 were infertile and all five with DNAH11 were fertile.

LIMITATIONS REASONS FOR CAUTION

The study has limitations, including potential selection bias as people experiencing problems with fertility might be more likely to fill in the questionnaire, which may have influenced our prevalence estimates. We were unable to validate clinical data obtained from participant self-reports owing to the anonymous study design, which is likely to lead to recall bias.

WIDER IMPLICATIONS OF THE FINDINGS

The study underlines the need for addressing infertility in routine PCD care, with a focus on informing individuals with PCD about their increased risk. It emphasizes the utility and efficacy of MAR in PCD-related infertility. Additionally, women attempting conception should be made aware of the increased risk of ectopic pregnancies and seek systematic early consultation to confirm an intrauterine pregnancy. Fertility, efficacy of MAR, and risk for adverse pregnancy outcomes differ between people with PCD-depending on genotypes-and close monitoring and support might be needed from fertility specialists to increase chances of successful conception.

STUDY FUNDING/COMPETING INTERESTS

Our research was funded by the Swiss National Science Foundation, Switzerland (SNSF 320030B_192804), the Swiss Lung Association, Switzerland (2021-08_Pedersen), and we also received support from the PCD Foundation, USA; the Verein Kartagener Syndrom und Primäre Ciliäre Dyskinesie, Germany; the PCD Support UK, UK; and PCD Australia, Australia. M. Goutaki received funding from the Swiss National Science Foundation, Switzerland (PZ00P3_185923). B. Maitre participates in the RaDiCo-DCP funded by INSERM France. The study authors participate in the BEAT-PCD Clinical Research Collaboration supported by the European Respiratory Society. All authors declare no conflict of interest.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov ID NCT04602481.

Primary Ciliary Dyskinesia: A Clinical Review

Primary ciliary dyskinesia (PCD) is a rare, genetically heterogeneous, motile ciliopathy, characterized by neonatal respiratory distress, recurrent upper and lower respiratory tract infections, subfertility, and laterality defects. Diagnosis relies on a combination of tests for confirmation, including nasal nitric oxide (nNO) measurements, high-speed videomicroscopy analysis (HSVMA), immunofluorescent staining, axonemal ultrastructure analysis via transmission electron microscopy (TEM), and genetic testing. Notably, there is no single gold standard confirmatory or exclusionary test. Currently, 54 causative genes involved in cilia assembly, structure, and function have been linked to PCD; this rare disease has a spectrum of clinical manifestations and emerging genotype-phenotype relationships. In this review, we provide an overview of the structure and function of motile cilia, the emerging genetics and pathophysiology of this rare disease, as well as clinical features associated with motile ciliopathies, novel diagnostic tools, and updates on genotype-phenotype relationships in PCD.

A Review: Biomechanical Aspects of the Fallopian Tube Relevant to its Function in Fertility

The fallopian tube (FT) plays a crucial role in the reproductive process by providing an ideal biomechanical and biochemical environment for fertilization and early embryo development. Despite its importance, the biomechanical functions of the FT that originate from its morphological aspects, and ultrastructural aspects, as well as the mechanical properties of FT, have not been studied nor used sufficiently, which limits the understanding of fertilization, mechanotrasduction, and mechanobiology during embryo development, as well as the replication of the FT in laboratory settings for infertility treatments. This paper reviews and revives valuable information on human FT reported in medical literature in the past five decades relevant to the biomechanical aspects of FT. In this review, we summarized the current state of knowledge concerning the morphological, ultrastructural aspects, and mechanical properties of the human FT. We also investigate the potential arising from a thorough consideration of the biomechanical functions and exploring often neglected mechanical aspects. Our investigation encompasses both macroscopic measurements (such as length, diameter, and thickness) and microscopic measurements (including the height of epithelial cells, the percentage of ciliated cells, cilia structure, and ciliary beat frequency). Our primary focus has been on healthy women of reproductive age. We have examined various measurement techniques, encompassing conventional metrology, 2D histological data as well as new spatial measurement techniques such as micro-CT.

[Primary ciliary dyskinesia]

Primary ciliary dyskinesia (PCD) is a rare genetic disorder with a variable clinical phenotype that is accompanied by reduced motility of the cilia in the respiratory tract and numerous other organs. This leads to various characteristic symptoms and disease manifestations, primarily affecting the lungs (chronic persistent productive cough, bronchiectasis), the nose and paranasal sinuses (chronic persistent rhinitis or rhinosinusitis) as well as the middle ear (chronic otitis media, middle ear effusion). Moreover, PCD is associated with impaired fertility or lateralization defects (situs anomalies, congenital heart defects). The diagnostics of PCD are complex and require a combination of several sophisticated instrument-based diagnostic procedures. Through thorough history taking and evaluation, suspected cases can be comparatively well identified based on typical clinical features and referred to further diagnostics. In recent years, molecular genetic analysis through panel diagnostics or whole exome and whole genome sequencing, has gained in importance as this enables affected individuals to participate in disease-specific and genotype-specific clinical trials. Although the current treatment is purely symptomatic, the earliest possible diagnosis is crucial for connecting patients to specialized PCD centers, which can have a significant impact on the clinical course of the affected individuals.

Flow Physics Explains Morphological Diversity of Ciliated Organs

Organs that pump fluids by the coordinated beat of motile cilia through the lumen are integral to animal physiology. Such organs include the human airways, brain ventricles, and reproductive tracts. Although cilia organization and duct morphology vary drastically in the animal kingdom, ducts are typically classified as either carpet or flame designs. The reason behind this dichotomy and how duct design relates to fluid pumping remain unclear. Here, we demonstrate that two structural parameters -- lumen diameter and cilia-to-lumen ratio -- organize the observed duct diversity into a continuous spectrum that connects carpets to flames across all animal phyla. Using a unified fluid model, we show that carpet and flame designs maximize flow rate and pressure generation, respectively. We propose that convergence of ciliated organ designs follows functional constraints rather than phylogenetic distance, along with universal design rules for ciliary pumps.

Cilia Structure and Function in Human Disease

Ciliary dysfunction causes a large group of developmental and degenerative human diseases known as ciliopathies. These diseases reflect the critical roles that cilia play in sensing the environment and in force generation for motility. Sensory functions include our senses of vision and olfaction. In addition, primary and motile cilia throughout our body monitor the environment allowing cells to coordinate their biology with the cells around them. This coordination is critical to organ development and maintenance, and ciliary dysfunction causes diverse structural birth defects and degenerative diseases. Defects in motility cause lung disease due to the failure of mucociliary clearance, male infertility due to the failure of sperm motility and the ability of sperm to move through the efferent ducts, and disturbances of the left-right axis due to a failure of nodal cilia to establish proper left-right cues.

Fertility care among people with primary ciliary dyskinesia

INTRODUCTION

Fertility care is important for people living with primary ciliary dyskinesia (PCD) who are at increased risk of fertility problems. We investigated fertility care in an international participatory study.

METHODS

Participants of the COVID-PCD study completed an online questionnaire addressing fertility issues. We used logistic regression to study factors associated with fertility specialist visits.

RESULTS

Among 384 respondents (response rate 53%), 266 were adults (median age 44 years, interquartile range [IQR]: 33-54, 68% female), 16 adolescents, and 102 parents of children with PCD. Only half of adult participants (128; 48%) received care from fertility specialists at a median age of 30 years (IQR: 27-33)-a median of 10 years after PCD diagnosis. Only 12% were referred to fertility specialists by their PCD physician. Fertility specialist visits were reported more often by adults with pregnancy attempts (odds ratio [OR]: 9.1, 95% confidence interval [CI]: 3.8-23.6) and among people who reported fertility as important for them (OR: 5.9, 95% CI: 2.6-14.6) and less often by females (OR: 0.4, 95% CI: 0.2-0.8). Only 56% of participants who talked with healthcare professionals about fertility were satisfied with information they received. They expressed needs for more comprehensive fertility information and reported dissatisfaction with physician knowledge about PCD and fertility.

CONCLUSION

People with PCD are inconsistently referred to fertility specialists. We recommend care from fertility specialists become standard in routine PCD care, and that PCD physicians provide initial fertility information either at diagnosis or no later than transition to adult care.

Adenosine Stimulates Beating of Neonatal Brain-Derived Cilia through Adenosine A2B Receptor on the Cilia and Activation of Protein Kinase A Pathway

Motile cilia in the ependymal cells that line the brain ventricles play pivotal roles in cerebrospinal fluid (CSF) flow in well-defined directions. However, the substances and pathways which regulate their beating have not been well studied. Here, we used primary cultured cells derived from neonatal mouse brain that possess motile cilia and found that adenosine (ADO) stimulates ciliary beating by increasing the ciliary beat frequency (CBF) in a concentration-dependent manner, with the ED50 value being 5 µM. Ciliary beating stimulated by ADO was inhibited by A2B receptor (A2BR) antagonist MRS1754 without any inhibition by antagonists of other ADO receptor subtypes. The expression of A2BR on the cilia was also confirmed by immunofluorescence. The values of CBF were also increased by forskolin, which is an activator of adenylate cyclase, whereas they were not further increased by the addition of ADO. Furthermore, ciliary beating was not stimulated by ADO in the presence of a protein kinase A (PKA) inhibitors. These results altogether suggest that ADO stimulates ciliary beating through A2BR on the cilia, and activation of PKA.

Single-cell transcriptomics identifies a WNT7A-FZD5 signaling axis that maintains fallopian tube stem cells in patient-derived organoids

The study of fallopian tube (FT) function in health and disease has been hampered by limited knowledge of FT stem cells and lack of in vitro models of stem cell renewal and differentiation. Using optimized organoid culture conditions to address these limitations, we find that FT stem cell renewal is highly dependent on WNT/β-catenin signaling and engineer endogenous WNT/β-catenin signaling reporter organoids to biomark, isolate, and characterize these cells. Using functional approaches, as well as bulk and single-cell transcriptomics analyses, we show that an endogenous hormonally regulated WNT7A-FZD5 signaling axis is critical for stem cell renewal and that WNT/β-catenin pathway-activated cells form a distinct transcriptomic cluster of FT cells enriched in extracellular matrix (ECM) remodeling and integrin signaling pathways. Overall, we provide a deep characterization of FT stem cells and their molecular requirements for self-renewal, paving the way for mechanistic work investigating the role of stem cells in FT health and disease.

Primary ciliary dyskinesia

BACKGROUND AND OBJECTIVES

Primary ciliary dyskinesia (PCD, ORPHA:244) is a group of rare genetic disorders characterized by dysfunction of motile cilia. It is phenotypically and genetically heterogeneous, with more than 50 genes involved. Thanks to genetic, clinical, and functional characterization, immense progress has been made in the understanding and diagnosis of PCD. Nevertheless, it is underdiagnosed due to the heterogeneous phenotype and complexity of diagnosis. This review aims to help clinicians navigate this heterogeneous group of diseases. Here, we describe the broad spectrum of phenotypes associated with PCD and address pitfalls and difficult-to-interpret findings to avoid misinterpretation.

METHOD

Review of literature CONCLUSION: PCD diagnosis is complex and requires integration of history, clinical picture, imaging, functional and structural analysis of motile cilia and, if available, genetic analysis to make a definitive diagnosis. It is critical that we continue to expand our knowledge of this group of rare disorders to improve the identification of PCD patients and to develop evidence-based therapeutic approaches.

Neofunctionalization of ciliary BBS proteins to nuclear roles is likely a frequent innovation across eukaryotes

The eukaryotic BBSome is a transport complex within cilia and assembled by chaperonin-like BBS proteins. Recent work indicates nuclear functions for BBS proteins in mammals, but it is unclear how common these are in extant proteins or when they evolved. We screened for BBS orthologues across a diverse set of eukaryotes, consolidated nuclear association via signal sequence predictions and permutation analysis, and validated nuclear localization in mammalian cells via fractionation and immunocytochemistry. BBS proteins are-with exceptions-conserved as a set in ciliated species. Predictions highlight five most likely nuclear proteins and suggest that nuclear roles evolved independently of nuclear access during mitosis. Nuclear localization was confirmed in human cells. These findings suggest that nuclear BBS functions are potentially not restricted to mammals, but may be a common frequently co-opted eukaryotic feature. Understanding the functional spectrum of BBS proteins will help elucidating their role in gene regulation, development, and disease.

Successful ART outcome with donor oocytes in female Kartagener's syndrome: a case report and follow-up

A 30-year-old woman presented with history of primary infertility of 8 years and multiple failed intrauterine insemination (IUI) attempts. She had the classic symptoms of Kartagener's syndrome-situs inversus, chronic sinusitis, and bronchiectasis. She had polycystic ovarian disease (PCOD) with regular menstrual cycles. Her karyotyping was normal. There was no other significant history including surgeries and the marriage was non-consanguineous. Her partner was 34 years old with normal semen and hormonal parameters. Her first intra-cytoplasmic sperm injection (ICSI) cycle with her own oocytes and husband's sperm resulted in a pregnancy but she suffered a miscarriage at 11 weeks. Her second attempt with donor oocytes and husband's sperm resulted in a pregnancy again but she miscarried at 9 weeks. The third attempt with a frozen embryo transfer with supernumerary embryos resulted in a pregnancy and she delivered a live female baby who was followed up for 8 years. This is the first report of a patient with KS undergoing assisted reproduction technologies (ART) treatment with donor oocytes. This is also the first Indian report of a female KS patient undergoing ART treatment with donor oocytes. IUI may not be the ideal treatment option in female patients with KS.

Cystic fibrosis and primary ciliary dyskinesia: Similarities and differences

Cystic fibrosis (CF) and Primary ciliary dyskinesia (PCD) are both rare chronic diseases, inherited disorders associated with multiple complications, namely respiratory complications, due to impaired mucociliary clearance that affect severely patients' lives. Although both are classified as rare diseases, PCD has a much lower prevalence than CF, particularly among Caucasians. As a result, CF is well studied, better recognized by clinicians, and with some therapeutic approaches already available. Whereas PCD is still largely unknown, and thus the approach is based on consensus guidelines, expert opinion, and extrapolation from the larger evidence base available for patients with CF. Both diseases have some clinical similarities but are very different, necessitating different treatment by specialists who are familiar with the complexities of each disease.This review aims to provide an overview of the knowledge about the two diseases with a focus on the similarities and differences between both in terms of disease mechanisms, common clinical manifestations, genetics and the most relevant therapeutic options. We hoped to raise clinical awareness about PCD, what it is, how it differs from CF, and how much information is still lacking. Furthermore, this review emphasises the fact that both diseases require ongoing research to find better treatments and, in particular for PCD, to fill the medical and scientific gaps.

Characterization of a DRC1 null variant associated with primary ciliary dyskinesia and female infertility

PROPOSE

We here present a female case with primary ciliary dyskinesia (PCD) and infertility. In this report, we also present the evaluation of the patient family, including her twin sister, also with PCD and infertility.

METHODS

Confirmation of the PCD clinical diagnosis was performed through assessment of cilia motility, by high-speed video microscopy (HSVM), axoneme ultrastructure, by transmission electron microscopy (TEM), and genetic characterization, by whole-exome sequence (WES). Gene expression studies used qPCR for mRNA expression and immunofluorescence to determine cell protein localization.

RESULTS

We identified a homozygous nonsense variant in the DRC1 gene (NM 145038.5:c.352C>T (p.Gln118Ter)) in the female patient with PCD and infertility that fit the model of autosomal recessive genetic transmission. This variant eventually results in a dyskinetic ciliary beat with a lower frequency and a partial lack of both dynein arms as revealed by TEM analysis. Moreover, this variant implies a decrease in the expression of DRC1 mRNA and protein. Additionally, expression analysis suggested that DRC1 may interact with other DRC elements.

CONCLUSIONS

Our findings suggest that the DRC1 null variant leads to PCD associated with infertility, likely caused by defects in axoneme from Fallopian tube cilia. Overall, our outcomes contribute to a better understanding of the genetic factors involved in the pathophysiology of PCD and infertility, and they highlight the interaction of different genes in the patient phenotype, which should be investigated further because it may explain the high heterogeneity observed in PCD patients.

Expression of Indian hedgehog signaling in murine oviductal infundibulum and its relationship with epithelial homeostasis

Homeostasis of the oviductal infundibulum epithelium is continuously regulated by signaling pathways under physiological and pathological conditions. Herein, we investigated the expression of hedgehog (Hh) signaling-related components in the murine oviductal infundibulum, which is known to maintain homeostasis in the adult epithelium. Additionally, using autoimmune disease-prone MRL/MpJ-Fas^lpr/lpr (MRL/lpr) mice showing abnormal morphofunction of the ciliated epithelium of the infundibulum related to the oviductal inflammation, we examined the relationship between Hh signaling and pathology of the infundibulum. The expression and localization of Pax8, a marker for progenitor cells in the oviductal epithelium, and Foxj1, a marker for ciliogenesis, were examined in the infundibulum. The results showed that Pax8 was downregulated and Foxj1 was upregulated with aging, suggesting that homeostasis of the infundibulum epithelium of MRL/lpr mice was disturbed at 6 months of age. In all mice, the motile cilia of ciliated epithelial cells in the infundibulum harbored Hh signaling pathway-related molecules: patched (Ptch), smoothened (Smo), and epithelial cells harbor Gli. In contrast, Ptch, Smo, and Gli2 were significantly downregulated in the infundibulum of MRL/lpr mice at 6 months of age. The expression levels of Pax8 and Foxj1 were significantly positively correlated with those of Ptch1, Smo, and Gli2. Hh signaling is thought to be involved in homeostasis of the ciliated epithelium in the infundibulum. In MRL/lpr mice, which show exacerbated severe systemic autoimmune abnormalities, molecular alterations in Hh signaling-related components are considered to interact with local inflammation in the infundibulum, leading to disturbances in epithelial homeostasis and reproductive function.

Impairment mechanism of nasal mucosa after radiotherapy for nasopharyngeal carcinoma

The nasal mucosa, which performs the crucial functions of filtering, humidifying and temperature regulation, is one of the most vulnerable areas of nasopharyngeal carcinoma (NPC) patients after radiotherapy (RT). Following RT, NPC patients experience a series of pathological changes in the nasal mucosa, ultimately leading to physiological dysfunction of the nasal epithelium. This article systematically reviews the clinical and pathological manifestations of RT-related nasal damage in NPC patients and summarizes the potential mechanism of damage to the human nasal epithelium by RT. Finally, we outline the current mechanistic models of nasal epithelial alterations after RT in NPC patients and provide additional information to extend the in-depth study on the impairment mechanisms of the nasal mucosa resulting from RT. We also describe the relationship between structural and functional alterations in the nasal mucosa after RT to help mitigate and treat this damage and provide insights informing future clinical and fundamental investigations.

Case Report:Pregnancy and birth in a mild phenotype of Alström syndrome

Background: Alström syndrome (AS) is an ultrarare multisystemic progressive disease caused by autosomal recessive variations of the ALMS1 gene (2p13). AS is characterized by double sensory impairment, cardiomyopathy, childhood obesity, extreme insulin resistance, early nonalcoholic fatty liver disease, renal dysfunction, respiratory disease, endocrine and urologic disorders. In female AS patients, hyperandrogenism has been described but fertility issues and conception have not been investigated so far.

Case: This case report describes the spontaneous conception, pregnancy, and birth in a 27-year-old woman with AS, characterized by a mild phenotype with late onset of visual impairment, residual perception of light, and hypertension. Before pregnancy, menses were regular with increased levels of dihydrotestosterone and androstanediol glucuronide in the follicular phase, and the ovaries and endometrium were normal during vaginal ultrasound. A thorough clinical follow-up of the maternal and fetal conditions was carried out. A weight gain of 10 kg during pregnancy was recorded, and serial blood and urine tests were all within the normal range, except for mild anemia. The course of pregnancy was uneventful up to 34 weeks of gestation when preeclampsia developed with an abnormally high level of blood pressure and edema in the lower limbs. At 35 weeks + 3 days of gestation, an urgent cesarean section was performed, and a healthy male weighing 1,950 g was born. Histological examination of the placenta showed partial signs of flow obstruction, limited abruption areas, congested fetal vessels and villi, and a small single infarcted area.

Conclusion: The present case demonstrates for the first time that conceiving is possible for patients with ALMS. Particular attention should be given to the management of AS systemic comorbidities through the course of pregnancy.

CDC42 governs normal oviduct multiciliogenesis through activating AKT to ensure timely embryo transport

Ciliated and secretory cells are two major cell types that comprise the oviduct epithelia. Accumulating evidences support a role of oviductal multiciliated epithelia for embryo transport, however the mechanisms underlying this specialized cell type differentiation remain elusive. Here, we report that CDC42 depletion in oviduct epithelia hampers the morphogenesis of multiciliated cell, and results in embryo retention, leading to early pregnancy failure. Utilizing the oviduct organoid model, we further observed that CDC42 guides secretory cells transition into multiciliated cells independent of its GTPase activity and the well-known Notch pathway. Further exploration uncovered the AKT as a novel indispensable regulator for multiciliated cells differentiation, whose activity was maintained by CDC42 through interacting with the p110β. Consistently, re-activating AKT partially incites multiciliated cells differentiation in Cdc42 knockout oviductal organoids. Finally, low levels of CDC42 and phospho-AKT with reduced multiciliated cells in the oviduct are observed in women with ectopic pregnancy. Collectively, we provide previously unappreciated evidence that CDC42-AKT signaling is a critical determinant for morphogenesis of oviduct multiciliated cell, which possesses the clinical application in understanding the pathology of ectopic pregnancy and facilitating the development of prevention strategies.

Endometrial gland specific progestagen-associated endometrial protein and cilia gene splicing changes in recurrent pregnancy loss

Endometrial glands are essential for fertility, consisting of ciliated and secretory cells that facilitate a suitable uterine environment for embryo implantation. This study sought to determine whether an endometrial gland specific transcriptome and splicing profile are altered in women with recurrent pregnancy loss. Our data provide a comprehensive catalogue of cilia and PAEP gene isoforms and relative exon usage in endometrial glands. We report a previously unannotated endometrial gland cilia transcript GALNT11 and its susceptibility to exon skipping. Key endometrial receptivity gene transcripts are also reported to change in endometrial glands of women with recurrent pregnancy loss. The endometrial gland cilia and PAEP targets identified in this study could be used to identify a perturbed endometrium, isolate causes of recurrent pregnancy loss and develop targeted therapies in personalised medicine.

Consensus nomenclature for dyneins and associated assembly factors

Dyneins are highly complex, multicomponent, microtubule-based molecular motors. These enzymes are responsible for numerous motile behaviors in cytoplasm, mediate retrograde intraflagellar transport (IFT), and power ciliary and flagellar motility. Variants in multiple genes encoding dyneins, outer dynein arm (ODA) docking complex subunits, and cytoplasmic factors involved in axonemal dynein preassembly (DNAAFs) are associated with human ciliopathies and are of clinical interest. Therefore, clear communication within this field is particularly important. Standardizing gene nomenclature, and basing it on orthology where possible, facilitates discussion and genetic comparison across species. Here, we discuss how the human gene nomenclature for dyneins, ODA docking complex subunits, and DNAAFs has been updated to be more functionally informative and consistent with that of the unicellular green alga Chlamydomonas reinhardtii, a key model organism for studying dyneins and ciliary function. We also detail additional nomenclature updates for vertebrate-specific genes that encode dynein chains and other proteins involved in dynein complex assembly.

Identification of Two Novel DNAAF2 Variants in Two Consanguineous Families with Primary Ciliary Dyskinesia

Background

Dynein axonemal assembly factor 2 (DNAAF2) is involved in the early preassembly of dynein in the cytoplasm, which is essential for motile cilia function. Primary ciliary dyskinesia (PCD) associated with DNAAF2 variants has rarely been reported in females with infertility. Moreover, there is no report linking DNAAF2 to scoliosis in human.

Materials and Methods

We recruited patients from two consanguineous families with a clinical diagnosis of PCD and collected their clinical history, laboratory tests, and radiographic data. Sequencing and bioinformatics analysis were then performed. Immunofluorescence and high-speed microscope analysis were used to support the pathogenicity of the variant.

Results

Proband 1, a 26-year-old female from family I, exhibited scoliosis, bronchiectasis, sinusitis, situs inversus, and infertility. We found a novel homozygous missense variant in DNAAF2, c.491T>C, p.(Leu164Pro) in this patient. Subsequent immunofluorescence indicated the absence of outer dynein arm and inner dynein arm of cilia, and high-speed microscopy analysis showed that the most of the cilia are static, which support the pathogenicity of this variant. Proband 2, a 53-year-old female, presented with bronchiectasis, sinusitis, and infertility. In this patient, a new homozygous frameshift variant DNAAF2, c.822del, p.(Ala275Profs*10) was identified. The disease-causing variants mentioned above are not included in the current authorized genetic databases.

Conclusion

Our findings expand the spectrum of DNAAF2 variants and link DNAAF2 to female infertility and likely scoliosis in patients with PCD.

Bi-allelic mutations in MCIDAS and CCNO cause human infertility associated with abnormal gamete transport

Reduced generation of multiple motile cilia (RGMC) and the consequent primary ciliary dyskinesia (PCD) cause infertility due to a substantial reduction in the number of multiciliated cells (MCCs) in the efferent ducts (EDs)/oviducts. MCIDAS acts upstream of CCNO to regulate the biogenesis of basal bodies (BBs); therefore, both genes play a vital role in the multiciliogenesis of the reproductive tract epithelium. In this study, whole-exome sequencing was performed to identify the causative genes in 10 unrelated infertile patients with PCD: seven males and three females. Notably, homozygous frameshift mutations in MCIDAS (c.186dupT, p.Pro63Serfs*22) and CCNO (c.262_263insGGCCC, p.Gln88Argfs*8) were identified in one male and one female participant from two unrelated consanguineous families. Haematoxylin-eosin staining/scanning electron microscopy revealed abnormal MCCs in the mutated EDs/oviducts. Furthermore, transmission electron microscopy revealed significantly reduced BBs. Immunofluorescence staining showed the absence of MCIDAS and CCNO signals in the affected tissues and confirmed that MCIDAS acts upstream of CCNO in the context of multiciliogenesis in the reproductive tract epithelium. In vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) was successful, with a positive pregnancy outcome in both MCIDAS- and CCNO-mutated patients. Our results support the use of IVF/ICSI interventions to treat infertility due to RGMC in couples.

Primary Ciliary Dyskinesia

Primary ciliary dyskinesia (PCD) is an inherited cause of bronchiectasis. The estimated PCD prevalence in children with bronchiectasis is up to 26% and in adults with bronchiectasis is 1 to 13%. Due to dysfunction of the multiple motile cilia of the respiratory tract patients suffer from poor mucociliary clearance. Clinical manifestations are heterogeneous; however, a typical patient presents with chronic productive cough and rhinosinusitis from early life. Other symptoms reflect the multiple roles of motile cilia in other organs and can include otitis media and hearing loss, infertility, situs inversus, complex congenital heart disease, and more rarely other syndromic features such as hydrocephalus and retinitis pigmentosa. Awareness, identification, and diagnosis of a patient with PCD are important for multidisciplinary care and genetic counseling. Diagnosis can be pursued through a multitest pathway which includes the measurement of nasal nitric oxide, sampling the nasal epithelium to assess ciliary function and structure, and genotyping. Diagnosis is confirmed by the identification of a hallmark ultrastructural defect or pathogenic mutations in one of > 45 PCD causing genes. When a diagnosis is established management is centered around improving mucociliary clearance through physiotherapy and treatment of infection with antibiotics. The first international randomized controlled trial in PCD has recently been conducted showing azithromycin is effective in reducing exacerbations. It is likely that evidence-based PCD-specific management guidelines and therapies will be developed in the near future. This article examines prevalence, clinical features, diagnosis, and management of PCD highlighting recent advances in basic science and clinical care.

Flow analysis of Carreau fluid model induced by the ciliary cells, smooth muscle cells and pressure gradient at the ampullar region entrance

This theoretical analysis considers a biomechanical model in which the Carreau fluid model characterizes the viscoelastic nature of growing human embryo and secreted fluid. This model incorporates transport mechanisms that involve the swaying motions of ciliary cells, peristaltic contractions of smooth muscle cells and pressure gradient at the ampullar region entrance. Series form solutions of the resulting partial differential equations are obtained using the regular perturbation method. A theoretical estimate of effects of the condition of pressure gradient, geometric parameters and fluid model parameters on the flow variables that have relevance to the problem of growing embryo transport in the human fallopian tube is presented through the discussion of graphs. Furthermore, an analogy between the linearly viscous fluid, and the shear thinning and shear thickening characteristics of the Carreau fluid model is also presented. The pertinence of the obtained results with growing embryo transport in the human fallopian tube revealed that when shear thickening characteristics of the Carreau fluid model are considered then complete mitotic divisions take place properly with an estimated appropriate residue time about 3-4 days. Smaller size trapped boluses of the secreted fluid make the smooth forwarding of the growing embryo in the human fallopian tube when shear thinning characteristics of the Carreau fluid model are taken into account. Key modulators: progesterone ([Formula: see text] and estradiol ([Formula: see text]), prostaglandin [Formula: see text] ([Formula: see text]) and prostaglandin [Formula: see text] ([Formula: see text]) constraint the growing embryo transport.

Cystic ovary disease impairs transport speed, smooth muscle contraction, and epithelial ion transport in the bovine oviduct

Cystic ovary disease (COD) is a common cause of bovine infertility but the impact of this disease on the oviduct is unknown. The aim of this study was to analyze the effects of COD on particle transport speed (PTS), ciliary beat frequency, myosalpinx contraction, and epithelial ion transport. Oviducts were obtained from cows affected by COD and compared with those of healthy, mid-diestrus cows. PTS and CBF were examined using live-cell imaging. Smooth muscle contraction and epithelial ion transport were investigated using organ baths and Ussing chambers. Our results showed that muscarinic receptors are involved in cholinergic signaling in the oviduct and that forskolin-induced cyclic AMP production is involved in active ion transport in the oviductal epithelium. Oviducts from cows with luteal cysts revealed significantly decreased PTS (p = 0.02). Further to that, in the oviducts of COD cows, the cholinergic regulation of smooth muscle contractions and active epithelial ion transport were significantly diminished (p < 0.0001). These results imply that in COD cows, oviductal transport is compromised by decreased fluid flow speed and reduced cholinergic regulation of smooth muscle contraction and ion transport. This knowledge contributes to a more comprehensive understanding of COD supporting the development of novel therapeutic concepts for infertility treatment.

Oviductal motile cilia are essential for oocyte pickup but dispensable for sperm and embryo transport

Mammalian oviducts play an essential role in female fertility by picking up ovulated oocytes and transporting and nurturing gametes (sperm/oocytes) and early embryos. However, the relative contributions to these functions from various cell types within the oviduct remain controversial. The oviduct in mice deficient in two microRNA (miRNA) clusters (miR-34b/c and miR-449) lacks cilia, thus allowing us to define the physiological role of oviductal motile cilia. Here, we report that the infundibulum without functional motile cilia failed to pick up the ovulated oocytes. In the absence of functional motile cilia, sperm could still reach the ampulla region, and early embryos managed to migrate to the uterus, but the efficiency was reduced. Further transcriptomic analyses revealed that the five messenger ribonucleic acids (mRNAs) encoded by miR-34b/c and miR-449 function to stabilize a large number of mRNAs involved in cilium organization and assembly and that Tubb4b was one of their target genes. Our data demonstrate that motile cilia in the infundibulum are essential for oocyte pickup and thus, female fertility, whereas motile cilia in other parts of the oviduct facilitate gamete and embryo transport but are not absolutely required for female fertility.

A report of pregnancy following ICSI in one of two sisters with familiar primary ciliary dyskinesia

Primary ciliary dyskinesia (PCD) is a disorder of structure and function of motor ciliary and dyskinetic activity of ciliary in the fallopian tubes of affected women and could lead to infertility in some cases. In vitro fertilisation (IVF) is a choice of treatment in infertile women with PCD, which could conquer the tubal dysfunction. In this case study, we report a PCD affected woman with infertility who was treated by IVF and pregnancy was achieved but it failed due to the spontaneous abortion. We also performed whole-exome sequencing for this case and her PCD-affected sister, which did not reveal any genetic abnormality related to the PCD or infertility.

Exposure of human fallopian tube epithelium to elevated testosterone results in alteration of cilia gene expression and beating

STUDY QUESTION

How does exposure to a testosterone rich environment affect the function and gene expression of human fallopian tube epithelium (hFTE)?

SUMMARY ANSWER

Elevated testosterone level alters several gene transcripts that regulate cilia expression and negatively impacts the rate of cilia beating.

WHAT IS KNOWN ALREADY

The presence of estrogen in the follicular phase of the menstrual cycle increases the human fallopian tube ciliary beating frequency. The luteal phase, triggered by ovulation and increasing progesterone, is marked by a decrease in ciliary beating. Women with polycystic ovarian syndrome (PCOS) may have twice the serum level of testosterone than ovulatory women. To date, the effect of elevated androgens on the function of the human fallopian tube is not well-understood. We chose to examine the impact of elevated testosterone on hFTE.

STUDY DESIGN, SIZE, DURATION

A prospective basic science study of human fallopian tube specimens from reproductive-aged women undergoing benign gynecologic surgery was performed. Fallopian tube removal at a large US academic center was collected and provided to us to continue with epithelium isolation and culturing. A total of 12 patients were analyzed in the study.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Fallopian tube epithelium was isolated and exposed to two different conditions: normal with low testosterone concentration of 0.8 nM and PCOS-like, with high testosterone concentration of 2 nM. The study was conducted in both static and dynamic conditions in microfluidic devices for a total of 14 days, after which the tissue was collected for processing including RNA extraction, quantitative PCR and immunohistochemistry. After the first 7 days of each experiment, a sample of tissue from each condition was imaged to quantify cilia beating frequency.

MAIN RESULTS AND THE ROLE OF CHANCE

hFTE exposed to the 2 nM testosterone displayed slower cilia beating, inhibited estrogen signaling and decreased expression of the ciliary marker FOXJ1 when compared to stimulation with 0.8 nM testosterone.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

The in vivo response to elevated testosterone may differ from in vitro studies. RNA amount was limited from tissue cultured in the microfluidic devices as compared to static culture.

WIDER IMPLICATIONS OF THE FINDINGS

Understanding elevated testosterone in tubal function may explain an additional contribution to subfertility in women with PCOS and other hyper-androgen disorders, aside from oligo-ovulation. Furthermore, this adds to the body of literature of fallopian tube function using a microfluidic device.

STUDY FUNDING/COMPETING INTEREST(S)

NIH grants: UH3 ES029073 and R01 CA240301. There are no competing interests.

Motility of efferent duct cilia aids passage of sperm cells through the male reproductive system

Motile cilia line the efferent ducts of the mammalian male reproductive tract. Several recent mouse studies have demonstrated that a reduced generation of multiple motile cilia in efferent ducts is associated with obstructive oligozoospermia and fertility issues. However, the sole impact of efferent duct cilia dysmotility on male infertility has not been studied so far either in mice or human. Using video microscopy, histological- and ultrastructural analyses, we examined male reproductive tracts of mice deficient for the axonemal motor protein DNAH5: this defect exclusively disrupts the outer dynein arm (ODA) composition of motile cilia but not the ODA composition and motility of sperm flagella. These mice have immotile efferent duct cilia that lack ODAs, which are essential for ciliary beat generation. Furthermore, they show accumulation of sperm in the efferent duct. Notably, the ultrastructure and motility of sperm from these males are unaffected. Likewise, human individuals with loss-of-function DNAH5 mutations present with reduced sperm count in the ejaculate (oligozoospermia) and dilatations of the epididymal head but normal sperm motility, similar to DNAH5 deficient mice. The findings of this translational study demonstrate, in both mice and men, that efferent duct ciliary motility is important for male reproductive fitness and uncovers a novel pathomechanism distinct from primary defects of sperm motility (asthenozoospermia). If future work can identify environmental factors or defects in genes other than DNAH5 that cause efferent duct cilia dysmotility, this will help unravel other causes of oligozoospermia and may influence future practices in genetic and fertility counseling as well as ART.

Aquatic models of human ciliary diseases

Cilia are microtubule-based structures that either transmit information into the cell or move fluid outside of the cell. There are many human diseases that arise from malfunctioning cilia. Although mammalian models provide vital insights into the underlying pathology of these diseases, aquatic organisms such as Xenopus and zebrafish provide valuable tools to help screen and dissect out the underlying causes of these diseases. In this review we focus on recent studies that identify or describe different types of human ciliopathies and outline how aquatic organisms have aided our understanding of these diseases.

Motile cilia and airway disease

A finely regulated system of airway epithelial development governs the differentiation of motile ciliated cells of the human respiratory tract, conferring the body's mucociliary clearance defence system. Human cilia dysfunction can arise through genetic mutations and this is a cause of debilitating disease morbidities that confer a greatly reduced quality of life. The inherited human motile ciliopathy disorder, primary ciliary dyskinesia (PCD), can arise from mutations in genes affecting various aspects of motile cilia structure and function through deficient production, transport and assembly of cilia motility components or through defective multiciliogenesis. Our understanding about the development of the respiratory epithelium, motile cilia biology and the implications for human pathology has expanded greatly over the past 20 years since isolation of the first PCD gene, rising to now nearly 50 genes. Systems level insights about cilia motility in health and disease have been made possible through intensive molecular and omics (genomics, transcriptomics, proteomics) research, applied in ciliate organisms and in animal and human disease modelling. Here, we review ciliated airway development and the genetic stratification that underlies PCD, for which the underlying genotype can increasingly be connected to biological mechanism and disease prognostics. Progress in this field can facilitate clinical translation of research advances, with potential for great medical impact, e.g. through improvements in ciliopathy disease diagnosis, management, family counselling and by enhancing the potential for future genetically tailored approaches to disease therapeutics.

Novel dynein axonemal assembly factor 1 mutations identified using whole‑exome sequencing in patients with primary ciliary dyskinesia

Primary ciliary dyskinesia (PCD) is a rare, genetically heterogeneous disorder caused by dysfunction of the cilia and flagella; however, causative genetic defects have not been detected in all patients with PCD. Seven Chinese Han patients with Kartagener syndrome were enrolled onto the present study. Transmission electron microscopy (TEM) was performed to evaluate the cilial defects and whole‑exome sequencing was used to analyze relevant genetic variations in all patients. In two of the seven patients with PCD, four novel dynein axonemal assembly factor 1 (DNAAF1) mutations were identified (NM_178452.6:c.3G>A, c.124+1G>C, c.509delG and c.943A>T) in three alleles. Both of these patients had long‑standing infertility. Their chest computed tomography results showed bronchiectasis, lung infections and situs inversus, and paranasal computed tomography revealed sinusitis. Semen analysis of the male patient showed poor sperm motility. TEM showed defects in the inner and outer dynein arms in both patients. The DNAAF1 sequences of family members were then analyzed. Bioinformatics analysis indicated that these mutations may be the cause of the cilial defects in these two probands. Thus, the present study identified novel PCD‑causing mutations in DNAAF1 in two patients with PCD. These genetic variations were predicted to alter DNAAF1 amino acid residues and lead to loss of function, thereby inhibiting cilia‑mediated motility. Accordingly, the two probands had PCD symptoms, and one of them died due to PCD‑associated complications.

[Management of Primary Ciliary Dyskinesia]

Die Primäre Ciliäre Dyskinesie (PCD, MIM 242650) ist eine seltene hereditäre Multisystemerkrankung mit klinisch heterogenem Phänotyp. Leitsymptom ist eine chronische Sekretretention der oberen und unteren Atemwege, welche durch die Dysfunktion motiler respiratorischer Zilien entsteht. In der Folge kommt es zur Ausbildung von Bronchiektasen, häufig zu einer Infektion durch Pseudomonas aeruginosa sowie einer abnehmenden Lungenfunktion bis hin zum Lungenversagen.

Bislang gibt es kaum evidenzbasierte Therapieempfehlungen, da randomisierte Langzeitstudien zur Behandlung der PCD fehlten. In diesem Jahr wurden die Daten einer ersten placebokontrollierten Medikamentenstudie bei PCD veröffentlicht. Anlässlich dieses Meilensteins im Management der PCD wurde der vorliegende Übersichtsartikel als Konsens von Patientenvertretern sowie Klinikern, die langjährige Erfahrung in der Behandlung der PCD haben, verfasst. Diese Arbeit bietet eine Zusammenfassung aktuell eingesetzter Behandlungsverfahren, die überwiegend auf persönlichen Erfahrungen und Expertenmeinungen beruhen oder von anderen Atemwegserkrankungen wie der Cystischen Fibrose (CF), COPD oder Bronchiektasen-Erkrankung abgeleitet werden. Da es derzeit keine kurative Therapie für PCD gibt, stehen symptomatische Maßnahmen wie die regelmäßige Reinigung der Atemwege und die Behandlung von rezidivierenden Atemwegsinfektionen im Fokus. Nicht respiratorische Manifestationen werden organspezifisch behandelt. Um neben der ersten Medikamentenstudie mehr evidenzbasiertes Wissen zu generieren, werden weitere Projekte etabliert, u. a. ein internationales PCD-Register. Hierüber wird Patienten der Zugang zu klinischen und wissenschaftlichen Studien erleichtert und die Vernetzung behandelnder Zentren gefördert. Des Weiteren können Erkenntnisse über eine Genotyp-spezifische Erkrankungsschwere erlangt werden, um folglich die therapeutische Versorgung der Patienten zu verbessern und somit zu individualisieren.

Motile ciliopathies

Motile cilia are highly complex hair-like organelles of epithelial cells lining the surface of various organ systems. Genetic mutations (usually with autosomal recessive inheritance) that impair ciliary beating cause a variety of motile ciliopathies, a heterogeneous group of rare disorders. The pathogenetic mechanisms, clinical symptoms and severity of the disease depend on the specific affected genes and the tissues in which they are expressed. Defects in the ependymal cilia can result in hydrocephalus, defects in the cilia in the fallopian tubes or in sperm flagella can cause female and male subfertility, respectively, and malfunctional motile monocilia of the left-right organizer during early embryonic development can lead to laterality defects such as situs inversus and heterotaxy. If mucociliary clearance in the respiratory epithelium is severely impaired, the disorder is referred to as primary ciliary dyskinesia, the most common motile ciliopathy. No single test can confirm a diagnosis of motile ciliopathy, which is based on a combination of tests including nasal nitric oxide measurement, transmission electron microscopy, immunofluorescence and genetic analyses, and high-speed video microscopy. With the exception of azithromycin, there is no evidence-based treatment for primary ciliary dyskinesia; therapies aim at relieving symptoms and reducing the effects of reduced ciliary motility.

Sperm defects in primary ciliary dyskinesia and related causes of male infertility

The core axoneme structure of both the motile cilium and sperm tail has the same ultrastructural 9 + 2 microtubular arrangement. Thus, it can be expected that genetic defects in motile cilia also have an effect on sperm tail formation. However, recent studies in human patients, animal models and model organisms have indicated that there are differences in components of specific structures within the cilia and sperm tail axonemes. Primary ciliary dyskinesia (PCD) is a genetic disease with symptoms caused by malfunction of motile cilia such as chronic nasal discharge, ear, nose and chest infections and pulmonary disease (bronchiectasis). Half of the patients also have situs inversus and in many cases male infertility has been reported. PCD genes have a role in motile cilia biogenesis, structure and function. To date mutations in over 40 genes have been identified cause PCD, but the exact effect of these mutations on spermatogenesis is poorly understood. Furthermore, mutations in several additional axonemal genes have recently been identified to cause a sperm-specific phenotype, termed multiple morphological abnormalities of the sperm flagella (MMAF). In this review, we discuss the association of PCD genes and other axonemal genes with male infertility, drawing particular attention to possible differences between their functions in motile cilia and sperm tails.

Long-term defects of nasal epithelium barrier functions in patients with nasopharyngeal carcinoma post chemo-radiotherapy

BACKGROUND AND PURPOSE

Chronic and recurrent upper respiratory tract infection and inflammation is common in patients with nasopharyngeal carcinoma (NPC) post chemo-radiotherapy (CRT). Whether it is due to intrinsic (e.g., host-defense mechanisms of the epithelium), epigenetic or extrinsic factors is not fully understood.

MATERIALS AND METHODS

Tissue biopsies of the middle turbinate (MT) and inferior turbinate (IT) from NPC patients after CRT (mean of 3 years, n = 39) were compared with the IT biopsies from healthy subjects (n = 44). The epithelial ultrastructure was examined by transmission electron microscope (TEM). mRNA and protein expressions of epithelial stem/progenitor cells markers, as well markers of cell proliferation and differentiation markers was analyzed.

RESULTS

Abnormal epithelial architecture was observed in all tissue samples of NPC patients. Significantly decreased expression levels of mRNA and protein levels for p63 (basal cells), Ki67 (cell proliferation), p63⁺/KRT5⁺ (epithelial stem/progenitor cells), MUC5AC and MUC5B (secretary proteins from goblet cells), alpha-tubulin, beta-tubulin and TAp73 (ciliated cells), DNAH5 and DNAI1 and RSPH4A (microtubule assemblies of motile cilia), FOXJ1 and CP110 (ciliogenesis-associated markers) were evident in MT and IT biopsies from NPC patients when compared to healthy controls.

CONCLUSION

CRT causes long-term defects of epithelial barrier functions and increases the susceptibility of these patients to upper respiratory tract infection and inflammation.

A genomics approach to females with infertility and recurrent pregnancy loss

Infertility affects 10% of reproductive-age women and is extremely heterogeneous in etiology. The genetic contribution to female infertility is incompletely understood, and involves chromosomal and single-gene defects. Our aim in this study is to decipher single-gene causes in infertile women in whom endocrinological, anatomical, and chromosomal causes have been excluded. Our cohort comprises women with recurrent pregnancy loss and no offspring from spontaneous pregnancies (RPL, n = 61) and those who never achieved clinical pregnancy and were referred for in vitro fertilization [primary infertility (PI), n = 14]. Whole-exome sequencing revealed candidate variants in 14, which represents 43% of those with PI and 13% of those with RPL. These include variants in previously established female infertility-related genes (TLE6, NLRP7, FSHR, and ZP1) as well as genes with only tentative links in the literature (NLRP5). Candidate variants in genes linked to primary ciliary dyskinesia (DNAH11 and CCNO) were identified in individuals with and without systemic features of the disease. We also identified variants in genes not previously linked to female infertility. These include one homozygous variant each in CCDC68, CBX3, CENPH, PABPC1L, PIF1, PLK1, and REXO4, which we propose as candidate genes for infertility based on their established biology or compatible animal models. Our study expands the contribution of single genes to the etiology of PI and RPL, improves the precision of disease classification at the molecular level, and offers the potential for future treatment and development of human genetics-inspired fertility regulators.

Frequency of Cystic Fibrosis Transmembrane Conductance Regulator Variants in Individuals Evaluated for Primary Ciliary Dyskinesia

OBJECTIVE

To evaluate whether cystic fibrosis transmembrane conductance regulator (CFTR) variants are more common among individuals tested for primary ciliary dyskinesia (PCD) compared with controls.

STUDY DESIGN

Data were studied from 1021 individuals with commercial genetic testing for suspected PCD and 91 777 controls with genetic testing at the same company (Invitae) for symptoms/diseases unrelated to PCD or CFTR testing. The prevalence of CFTR variants was compared between controls and each of 3 groups of individuals tested for PCD (PCD-positive, -uncertain, and -negative molecular diagnosis).

RESULTS

The prevalence of 1 pathogenic CFTR variant was similar among the individual groups. When combining the PCD-uncertain and PCR-negative molecular diagnosis groups, there was a higher prevalence of single pathogenic CFTR variants compared with controls (P = .03). Importantly, >1% of individuals who had negative genetic testing results for PCD had 2 pathogenic CFTR variants (8 of 723), and the incidence of cystic fibrosis (CF) (2 pathogenic variants) is roughly 1 in 3000 individuals of Caucasian ethnicity (∼0.03%). This incidence was also greater than that of 2 pathogenic CFTR variants in the control population (0.09% [84 of 91 777]; P = 9.60 × 10^-16). These variants correlate with mild CFTR-related disease.

CONCLUSIONS

Our results suggest that a single pathogenic CFTR variant is not likely to be a PCD-mimetic, but ongoing studies are needed in individuals in whom PCD is suspected and genetic testing results are uncertain or negative. Furthermore, CF may be misdiagnosed as PCD, reflecting phenotypic overlap. Among individuals evaluated for PCD, CF should be considered in the differential even in the CF newborn screening era.

De Novo Mutations in FOXJ1 Result in a Motile Ciliopathy with Hydrocephalus and Randomization of Left/Right Body Asymmetry

Hydrocephalus is one of the most prevalent form of developmental central nervous system (CNS) malformations. Cerebrospinal fluid (CSF) flow depends on both heartbeat and body movement. Furthermore, it has been shown that CSF flow within and across brain ventricles depends on cilia motility of the ependymal cells lining the brain ventricles, which play a crucial role to maintain patency of the narrow sites of CSF passage during brain formation in mice. Using whole-exome and whole-genome sequencing, we identified an autosomal-dominant cause of a distinct motile ciliopathy related to defective ciliogenesis of the ependymal cilia in six individuals. Heterozygous de novo mutations in FOXJ1, which encodes a well-known member of the forkhead transcription factors important for ciliogenesis of motile cilia, cause a motile ciliopathy that is characterized by hydrocephalus internus, chronic destructive airway disease, and randomization of left/right body asymmetry. Mutant respiratory epithelial cells are unable to generate a fluid flow and exhibit a reduced number of cilia per cell, as documented by high-speed video microscopy (HVMA), transmission electron microscopy (TEM), and immunofluorescence analysis (IF). TEM and IF demonstrate mislocalized basal bodies. In line with this finding, the focal adhesion protein PTK2 displays aberrant localization in the cytoplasm of the mutant respiratory epithelial cells.

Characterization of Primary Cilia in Normal Fallopian Tube Epithelium and Serous Tubal Intraepithelial Carcinoma

Supplemental digital content is available in the text.

Objectives

The aim of this study was to investigate the distribution of primary cilia on secretory cells in normal fallopian tube (FT) and serous tubal intraepithelial carcinoma (STIC).

Methods

Fallopian tube tissue samples were obtained from 4 females undergoing prophylactic hysterectomies and 6 patients diagnosed with STIC. A mogp-TAg transgenic mouse STIC sample was also compared with a wild-type mouse FT sample. Serous tubal intraepithelial carcinoma was identified by hematoxylin and eosin staining and confirmed by positive Ki-67 and p53 immunohistochemical staining of tissue sections. We assessed the relative distribution of primary cilia on secretory cells and motile cilia on multiple ciliated cells by immunofluorescence and immunohistochemical staining. Ciliary function was assessed by immunofluorescence staining of specific ciliary marker proteins and responsiveness to Sonic Hedgehog signaling.

Results

Primary cilia are widespread on secretory cells in the ampulla, isthmus, and in particular, the fimbriae of human FT where they may appear to mediate ciliary-mediated Sonic Hedgehog signaling. A statistically significant reduction in the number of primary cilia on secretory cells was observed in human STIC samples compared with normal controls (P < 0.0002, Student t test), supported by similar findings in a mouse STIC sample. Immunohistochemical staining for dynein axonemal heavy chain 5 discriminated multiple motile cilia from primary cilia in human FT.

Conclusions

Primary cilia are widespread on secretory cells in the ampulla, isthmus, and in particular, the fimbriae of the human FT but are significantly reduced in both human and mouse STIC samples. Immunohistochemical staining for ciliary proteins may have clinical utility for early detection of STIC.

Transcription factor TAp73 and microRNA-449 complement each other to support multiciliogenesis

Motile cilia serve vital functions in development, homeostasis, and regeneration. We recently demonstrated that TAp73 is an essential transcriptional regulator of respiratory multiciliogenesis. Here, we show that TAp73 is expressed in multiciliated cells (MCCs) of diverse tissues. Analysis of TAp73 mutant animals revealed that TAp73 regulates Foxj1, Rfx2, Rfx3, axonemal dyneins Dnali1 and Dnai1, plays a pivotal role in the generation of MCCs in male and female reproductive ducts, and contributes to fertility. However, the function of MCCs in the brain appears to be preserved despite the loss of TAp73, and robust activity of cilia-related networks is maintained in the absence of TAp73. Notably, TAp73 loss leads to distinct changes in ciliogenic microRNAs: miR34bc expression is reduced, whereas the miR449 cluster is induced in diverse multiciliated epithelia. Among different MCCs, choroid plexus (CP) epithelial cells in the brain display prominent miR449 expression, whereas brain ventricles exhibit significant increase in miR449 levels along with an increase in the activity of ciliogenic E2F4/MCIDAS circuit in TAp73 mutant animals. Conversely, E2F4 induces robust transcriptional response from miR449 genomic regions. To address whether increased miR449 levels in the brain maintain the multiciliogenesis program in the absence of TAp73, we deleted both TAp73 and miR449 in mice. Although loss of miR449 alone led to a mild ciliary defect in the CP, more pronounced ciliary defects and hydrocephalus were observed in the brain lacking both TAp73 and miR449. In contrast, miR449 loss in other MCCs failed to enhance ciliary defects associated with TAp73 loss. Together, our study shows that, in addition to the airways, TAp73 is essential for generation of MCCs in male and female reproductive ducts, whereas miR449 and TAp73 complement each other to support multiciliogenesis and CP development in the brain.

Exploring the Role of Fallopian Ciliated Cells in the Pathogenesis of High-Grade Serous Ovarian Cancer

High-grade serous epithelial ovarian cancer (HGSOC) is the fifth leading cause of cancer death in women and the first among gynecological malignancies. Despite an initial response to standard chemotherapy, most HGSOC patients relapse. To improve treatment options, we must continue investigating tumor biology. Tumor characteristics (e.g., risk factors and epidemiology) are valuable clues to accomplish this task. The two most frequent risk factors for HGSOC are the lifetime number of ovulations, which is associated with increased oxidative stress in the pelvic area caused by ovulation fluid, and a positive family history due to genetic factors. In the attempt to identify novel genetic factors (i.e., genes) associated with HGSOC, we observed that several genes in linkage with HGSOC are expressed in the ciliated cells of the fallopian tube. This finding made us hypothesize that ciliated cells, despite not being the cell of origin for HGSOC, may take part in HGSOC tumor initiation. Specifically, malfunction of the ciliary beat impairs the laminar fluid flow above the fallopian tube epithelia, thus likely reducing the clearance of oxidative stress caused by follicular fluid. Herein, we review the up-to-date findings dealing with HGSOC predisposition with the hypothesis that fallopian ciliated cells take part in HGSOC onset. Finally, we review the up-to-date literature concerning genes that are located in genomic loci associated with epithelial ovarian cancer (EOC) predisposition that are expressed by the fallopian ciliated cells.

Advances in the Genetics of Primary Ciliary Dyskinesia: Clinical Implications

Primary ciliary dyskinesia is a rare genetic disease of the motile cilia and is one of a rapidly expanding collection of disorders known as ciliopathies. Patients with primary ciliary dyskinesia have diverse clinical manifestations, including chronic upper and lower respiratory tract disease, left-right laterality defects, and infertility. In recent years, our understanding of the genetics of primary ciliary dyskinesia has rapidly advanced. A growing number of disease-associated genes and pathogenic mutations have been identified, which encode axonemal, cytoplasmic, and regulatory proteins involved in the assembly, structure, and function of motile cilia. Our knowledge of cilia genetics and the function of the proteins encoded has led to a greater understanding of the clinical manifestations of motile ciliopathies. These advances have changed our approach toward diagnostic testing for primary ciliary dyskinesia. In this review, we will describe how new insights into genetics have allowed us to define the clinical features of primary ciliary dyskinesia, revolutionize diagnostics, and reveal previously unrecognized genotype-phenotype relationships in primary ciliary dyskinesia.

Effects of pelvic endometriosis and adenomyosis on ciliary beat frequency and muscular contractions in the human fallopian tube

BACKGROUND

Pelvic endometriosis (EM) and adenomyosis (AM) have different effects on the fallopian tube. This study aimed to assess the transport capability of the fallopian tube in women with pelvic EM or AM.

METHODS

Twenty women with uterine leiomyoma (control group), 20 with adenomyosis without pelvic EM (AM group) and 35 with pelvic EM without AM (EM group) were included. EM cases were further divided into the tubal EM and non-tubal EM subgroups. Ciliary beat frequency (CBF), percentage of ciliated cells, and smooth muscle contraction were measured.

RESULTS

CBFs of the ampulla in EM cases were significantly lower than those of control and AM cases; CBFs of the ampulla and isthmus in tubal EM cases were significantly lower than those of the control group and non-tubal EM subgroup. In both the ampulla and isthmus segment, percentages of ciliated cells in EM patients were significantly lower than those of AM and control patients; the tubal EM subgroup showed significantly lower values than the control group and non-tubal EM subgroup. Amplitude-to-weight ratios of longitudinal muscular contractility in EM cases were significantly lower than control values; tubal EM cases showed significantly lower values than controls and the non-tubal EM subgroup. Contraction frequencies in EM cases were significantly lower than those of control and AM cases, in both longitudinal and circular muscles; tubal EM cases showed significantly lower values than controls and the non-tubal EM subgroup.

CONCLUSION

EM with tubal EM damaged transport function of the fallopian tube, to varying degrees, whereas tubal function in EM without tubal EM and in AM is not altered.

Sensing the cilium, digital capture of ciliary data for comparative genomics investigations

Background

Cilia are specialized, hair-like structures that project from the cell bodies of eukaryotic cells. With increased understanding of the distribution and functions of various types of cilia, interest in these organelles is accelerating. To effectively use this great expansion in knowledge, this information must be made digitally accessible and available for large-scale analytical and computational investigation. Capture and integration of knowledge about cilia into existing knowledge bases, thus providing the ability to improve comparative genomic data analysis, is the objective of this work.

Methods

We focused on the capture of information about cilia as studied in the laboratory mouse, a primary model of human biology. The workflow developed establishes a standard for capture of comparative functional data relevant to human biology. We established the 310 closest mouse orthologs of the 302 human genes defined in the SYSCILIA Gold Standard set of ciliary genes. For the mouse genes, we identified biomedical literature for curation and used Gene Ontology (GO) curation paradigms to provide functional annotations from these publications.

Results

Employing a methodology for comprehensive capture of experimental data about cilia genes in structured, digital form, we established a workflow for curation of experimental literature detailing molecular function and roles of cilia proteins starting with the mouse orthologs of the human SYSCILIA gene set. We worked closely with the GO Consortium ontology development editors and the SYSCILIA Consortium to improve the representation of ciliary biology within the GO. During the time frame of the ontology improvement project, we have fully curated 134 of these 310 mouse genes, resulting in an increase in the number of ciliary and other experimental annotations.

Conclusions

We have improved the GO annotations available for mouse genes orthologous to the human genes in the SYSCILIA Consortium’s Gold Standard set. In addition, ciliary terminology in the GO itself was improved in collaboration with GO ontology developers and the SYSCILIA Consortium. These improvements to the GO terms for the functions and roles of ciliary proteins, along with the increase in annotations of the corresponding genes, enhance the representation of ciliary processes and localizations and improve access to these data during large-scale bioinformatic analyses.

Electronic supplementary material

The online version of this article (10.1186/s13630-018-0057-0) contains supplementary material, which is available to authorized users.