bims-bicyki 2021-04-18 papers

bims-bicyki

Biomed News

on Bicaudal-C1 and interactors in cystic kidney disease

Issue of 2021–04–18
24 papers selected by
Céline Gagnieux, École Polytechnique Fédérale de Lausanne

A methionine-Mettl3-N6-methyladenosine axis promotes polycystic kidney disease.
Renal Squamous Cell Carcinoma-related Polymyositis in a Patient with Autosomal Dominant Polycystic Kidney Disease.
Sequential Liver-Kidney Transplantation for Recurrent Liver Cysts Infection in a Patient With Autosomal Dominant Polycystic Kidney Disease: A Case Report.
A Web of Science-based scientometric analysis about mammalian target of rapamycin signaling pathway in kidney disease from 1986 to 2020.
Preventive project of Autosomal Dominant Polycystic Kidney Disease (ADPKD).
A complex of distal appendage-associated kinases linked to human disease regulates ciliary trafficking and stability.
Time-resolved proteomics profiling of the ciliary Hedgehog response.
CDKL kinase regulates the length of the ciliary proximal segment.
Evaluation of sirtuin 1 (SIRT1) levels in autosomal dominant polycystic kidney disease.
CRISPR/Cas9-mediated mutagenesis reveals the roles of Calaxin in gastropod larval cilia.
Attenuation of the extracellular matrix increases the number of synapses but suppresses synaptic plasticity through upregulation of SK channels.
Moonlighting of mitotic regulators in cilium disassembly.
Effectively Intervening Epithelial-Mesenchymal Transition of Retinal Pigment Epithelial Cells With a Combination of ROCK and TGF-β Signaling Inhibitors.
A ZFYVE19 gene mutation associated with neonatal cholestasis and cilia dysfunction: case report with a novel pathogenic variant.
Imaging manifestations of Caroli disease with autosomal recessive polycystic kidney disease: a case report and literature review.
STORM imaging reveals the spatial arrangement of transition zone components and IFT particles at the ciliary base in Tetrahymena.
The implication of ROCK 2 as a potential senotherapeutic target via the suppression of the harmful effects of the SASP: Do senescent cancer cells really engulf the other cells?
Primary cilia and the DNA damage response: linking a cellular antenna and nuclear signals.
BBS4 protein has basal body/ciliary localization in sensory organs but extra-ciliary localization in oligodendrocytes during human development.
Structural insights into the cause of human RSPH4A primary ciliary dyskinesia.
Modulating the Electrical and Mechanical Microenvironment to Guide Neuronal Stem Cell Differentiation.
[Phosphorus binders: trigger for intestinal diverticula formation in an ADPKD patient].
ARHGEF18/p114RhoGEF Coordinates PKA/CREB Signaling and Actomyosin Remodeling to Promote Trophoblast Cell-Cell Fusion During Placenta Morphogenesis.
Semaphorin3F Drives Dendritic Spine Pruning Through Rho-GTPase Signaling.

Cell Metab. 2021 Apr 09. pii: S1550-4131(21)00131-5. [Epub ahead of print]

A methionine-Mettl3-N6-methyladenosine axis promotes polycystic kidney disease.

Harini Ramalingam, Sonu Kashyap, Patricia Cobo-Stark, Andrea Flaten, Chun-Mien Chang, Sachin Hajarnis, Kyaw Zaw Hein, Jorgo Lika, Gina M Warner, Jair M Espindola-Netto, Ashwani Kumar, Mohammed Kanchwala, Chao Xing, Eduardo N Chini, Vishal Patel.

  Autosomal dominant polycystic kidney disease (ADPKD) is a common monogenic disorder marked by numerous progressively enlarging kidney cysts. Mettl3, a methyltransferase that catalyzes the abundant N6-methyladenosine (m6A) RNA modification, is implicated in development, but its role in most diseases is unknown. Here, we show that Mettl3 and m6A levels are increased in mouse and human ADPKD samples and that kidney-specific transgenic Mettl3 expression produces tubular cysts. Conversely, Mettl3 deletion in three orthologous ADPKD mouse models slows cyst growth. Interestingly, methionine and S-adenosylmethionine (SAM) levels are also elevated in ADPKD models. Moreover, methionine and SAM induce Mettl3 expression and aggravate ex vivo cyst growth, whereas dietary methionine restriction attenuates mouse ADPKD. Finally, Mettl3 activates the cyst-promoting c-Myc and cAMP pathways through enhanced c-Myc and Avpr2 mRNA m6A modification and translation. Thus, Mettl3 promotes ADPKD and links methionine utilization to epitranscriptomic activation of proliferation and cyst growth.

Keywords:  AVPR2; METTL3; N(6)-methyladenosine; S-adenosylmethionine; c-Myc; m6A mRNA methylation; mRNA translation; methionine; polycystic kidney disease

DOI:  https://doi.org/10.1016/j.cmet.2021.03.024
Intern Med. 2021 ;60(8): 1237-1242

Renal Squamous Cell Carcinoma-related Polymyositis in a Patient with Autosomal Dominant Polycystic Kidney Disease.

Kanako Terakawa, Naoki Sawa, Hiroki Mizuno, Akinari Sekine, Noriko Hayami, Daisuke Ikuma, Masahiro Kawada, Rikako Hiramatsu, Keiichi Sumida, Masayuki Yamanouchi, Eiko Hasegawa, Tatsuya Suwabe, Junichi Hoshino, Keiichi Kinowaki, Kenichi Ohashi, Takeshi Fujii, Yoshifumi Ubara.

  A 74-year-old Japanese woman diagnosed with autosomal dominant polycystic kidney disease (ADPKD) was admitted to our institute for the further examination of right-side groin pain developing in the past week. The patient was diagnosed with polymyositis (PM). Diagnostic imaging showed a mass lesion measuring 8 cm and a renal stone in the right kidney. Immediately following surgical resection of the right kidney, the patient's serum CK decreased to the normal range. A histopathological analysis showed well-differentiated squamous cell carcinoma. In conclusion, this case showed a close relationship between the occurrence of squamous cell carcinoma and the development of PM in an ADPKD patient.

Keywords:  autosomal dominant polycystic kidney disease; paraneoplastic syndrome; polymyositis; renal pelvis cancer; squamous cell carcinoma; squamous metaplasia

DOI:  https://doi.org/10.2169/internalmedicine.5375-20
Transplant Proc. 2021 Apr 12. pii: S0041-1345(21)00145-7. [Epub ahead of print]

Sequential Liver-Kidney Transplantation for Recurrent Liver Cysts Infection in a Patient With Autosomal Dominant Polycystic Kidney Disease: A Case Report.

Zaina Issa, Olga Ciccarelli, Arnaud Devresse, Nada Kanaan, Eva Larranaga Lapique, Julien De Greef, Renaud Lhommel, Anja Kerschen, Mina Komuta, Bénédicte Delire, Géraldine Dahlqvist.

Autosomal dominant polycystic kidney disease (ADPKD) is the most prevalent hereditary kidney disorder. Liver cysts are the most common extrarenal manifestation of the disease and usually remain asymptomatic. Liver cyst infection is rare, and its treatment is challenging. Liver transplantation (LT) is the only curative therapeutic option in symptomatic polycystic liver disease associated with ADPKD. Only a few cases of LT for recurrent liver cyst infection have been published. To our knowledge, we report the first case of sequential liver-kidney transplantation for recurrent liver cysts infection in a patient with ADPKD. A 55-year-old woman with ADPKD who had a kidney transplantation (KT) presented with multiple liver cysts infection 9 months after her KT. These episodes started after biliary tract complications due to an ampullary adenoma necessitating multiple endoscopic interventions. Her general status gradually degraded because antibiotic treatment was not effective, and she underwent LT for recurrent liver cysts infection 1 year and 9 months after her KT. LT in this setting turned out to be challenging but was possible. We think that better biliary tract workup before KT may prompt better care in these patients.

DOI: https://doi.org/10.1016/j.transproceed.2021.02.018
Transl Androl Urol. 2021 Mar;10(3): 1006-1017

A Web of Science-based scientometric analysis about mammalian target of rapamycin signaling pathway in kidney disease from 1986 to 2020.

Lian-Zhong Wu, Yi-Qin Weng, Yi-Xin Ling, Shu-Juan Zhou, Xiao-Kai Ding, Si-Qi Wu, Kang Yu, Song-Fu Jiang, Yi Chen.

   Background: The mammalian target of rapamycin (mTOR) signaling pathway is vital for the regulation of cell metabolism, growth and proliferation in the kidney. This study aims to show current research focuses and predict future trends about mTOR pathway in kidney disease by the methods of scientometric analysis.
Methods: We referred to publications from the Web of ScienceTM Core Collection (WoSCC) Database. Carrot2, VOSviewer and CiteSpace programs were applied to evaluate the distribution and contribution of authors, institutes and countries/regions of extensive bibliographic metadata, show current research focuses and predict future trends in kidney disease's area.
Results: Until July 10, 2020, there are 2,585 manuscripts about mTOR signaling pathway in kidney disease in total and every manuscript is cited 27.39 times on average. The big name of course is the United States. Research hot spots include "diabetic nephropathy", "kidney transplantation", "autosomal dominant polycystic kidney disease", "tuberous sclerosis complex", "renal cell carcinoma" and "autophagy". Seven key clusters are detected, including "kidney transplantation", "autosomal dominant polycystic kidney disease", "renal transplantation", "renal cell carcinoma", "hamartin", "autophagy" and "tuberous sclerosis complex".
Conclusions: Diabetic nephropathy, kidney transplantation, autosomal dominant polycystic kidney disease, tuberous sclerosis complex, renal cell carcinoma and autophagy are future research hot spots by utilizing scientometric analysis. In the future, it is necessary to research these fields.

Keywords:  Bibliometrics; CiteSpace; TOR serine-threonine kinases; VOSviewer; kidney diseases

DOI:  https://doi.org/10.21037/tau-20-1469
Nefrologia. 2021 Apr 12. pii: S0211-6995(21)00062-X. [Epub ahead of print]

Preventive project of Autosomal Dominant Polycystic Kidney Disease (ADPKD).

Rafael J Esteban de la Rosa, Antonio Miguel Poyatos Andújar, Ana Isabel Morales García, Luis Martínez Navarro, María García Valverde, Juan Antonio Bravo Soto.

DOI: https://doi.org/10.1016/j.nefro.2020.11.022
Proc Natl Acad Sci U S A. 2021 Apr 20. pii: e2018740118. [Epub ahead of print]118(16):

A complex of distal appendage-associated kinases linked to human disease regulates ciliary trafficking and stability.

Abdelhalim Loukil, Chloe Barrington, Sarah C Goetz.

  Cilia biogenesis is a complex, multistep process involving the coordination of multiple cellular trafficking pathways. Despite the importance of ciliogenesis in mediating the cellular response to cues from the microenvironment, we have only a limited understanding of the regulation of cilium assembly. We previously identified Tau tubulin kinase 2 (TTBK2) as a key regulator of ciliogenesis. Here, using CRISPR kinome and biotin identification screening, we identify the CK2 catalytic subunit CSNK2A1 as an important modulator of TTBK2 function in cilia trafficking. Superresolution microscopy reveals that CSNK2A1 is a centrosomal protein concentrated at the mother centriole and associated with the distal appendages. Csnk2a1 mutant cilia are longer than those of control cells, showing instability at the tip associated with ciliary actin cytoskeleton changes. These cilia also abnormally accumulate key cilia assembly and SHH-related proteins. De novo mutations of Csnk2a1 were recently linked to the human genetic disorder Okur-Chung neurodevelopmental syndrome (OCNDS). Consistent with the role of CSNK2A1 in cilium stability, we find that expression of OCNDS-associated Csnk2a1 variants in wild-type cells causes ciliary structural defects. Our findings provide insights into mechanisms involved in ciliary length regulation, trafficking, and stability that in turn shed light on the significance of cilia instability in human disease.

Keywords:  CSNK2A1; OCNDS; TTBK2; actin modulators; primary cilia

DOI:  https://doi.org/10.1073/pnas.2018740118
J Cell Biol. 2021 May 03. pii: e202007207. [Epub ahead of print]220(5):

Time-resolved proteomics profiling of the ciliary Hedgehog response.

Elena A May, Marian Kalocsay, Inès Galtier D'Auriac, Patrick S Schuster, Steven P Gygi, Maxence V Nachury, David U Mick.

The primary cilium is a signaling compartment that interprets Hedgehog signals through changes of its protein, lipid, and second messenger compositions. Here, we combine proximity labeling of cilia with quantitative mass spectrometry to unbiasedly profile the time-dependent alterations of the ciliary proteome in response to Hedgehog. This approach correctly identifies the three factors known to undergo Hedgehog-regulated ciliary redistribution and reveals two such additional proteins. First, we find that a regulatory subunit of the cAMP-dependent protein kinase (PKA) rapidly exits cilia together with the G protein-coupled receptor GPR161 in response to Hedgehog, and we propose that the GPR161/PKA module senses and amplifies cAMP signals to modulate ciliary PKA activity. Second, we identify the phosphatase Paladin as a cell type-specific regulator of Hedgehog signaling that enters primary cilia upon pathway activation. The broad applicability of quantitative ciliary proteome profiling promises a rapid characterization of ciliopathies and their underlying signaling malfunctions.

DOI: https://doi.org/10.1083/jcb.202007207
Curr Biol. 2021 Apr 08. pii: S0960-9822(21)00441-3. [Epub ahead of print]

CDKL kinase regulates the length of the ciliary proximal segment.

Kwangjin Park, Chunmei Li, Sofia Tsiropoulou, João Gonçalves, Christine Kondratev, Laurence Pelletier, Oliver E Blacque, Michel R Leroux.

  Cilia are organelles found throughout most unicellular eukaryotes and different metazoan cell types. To accomplish their essential roles in cell motility, fluid flow, and signaling, cilia are divided into subcompartments with variable structures, compositions, and functions. How these specific subcompartments are built remains almost completely unexplored. Here, we show that C. elegans CDKL-1, related to the human CDKL kinase family (CDKL1/CDKL2/CDKL3/CDKL4/CDKL5), specifically controls the length of the proximal segment, a ciliary subdomain conserved in evolution from Tetrahymena motile cilia to C. elegans chemosensory, mammalian olfactory, and photoreceptor non-motile cilia. CDKL-1 associates with intraflagellar transport (IFT), influences the distribution of the IFT anterograde motors heterotrimeric kinesin-II and homodimeric OSM-3-kinesin/KIF17 in the proximal segment, and shifts the boundary between the proximal and distal segments (PS/DS boundary). CDKL-1 appears to function independently from several factors that influence cilium length, namely the kinases DYF-5 (mammalian CILK1/MAK) and NEKL-1 (NEK9), as well as the depolymerizing kinesins KLP-13 (KIF19) and KLP-7 (KIF2). However, a different kinase, DYF-18 (CCRK), is needed for the correct localization and function of CDKL-1 and similarly influences the length of the proximal segment. Loss of CDKL-1, which affects proximal segment length without impairing overall ciliary microtubule structural integrity, also impairs cilium-dependent processes, namely cGMP-signaling-dependent body length control and CO2 avoidance. Collectively, our findings suggest that cilium length is regulated by various pathways and that the IFT-associated kinase CDKL-1 is essential for the construction of a specific ciliary compartment and contributes to development and sensory physiology.

Keywords:  CDKL; cilia; ciliopathy; cilium length; development; kinase; proximal segment; signaling

DOI:  https://doi.org/10.1016/j.cub.2021.03.068
Int Urol Nephrol. 2021 Apr 17.

Evaluation of sirtuin 1 (SIRT1) levels in autosomal dominant polycystic kidney disease.

Pervin Ozkan Kurtgoz, Suleyman Karakose, Cigdem Damla Cetinkaya, Edip Erkus, Ibrahim Guney.

   PURPOSE: Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic kidney disease and the majority of patients have a PKD-1 or PKD-2 mutation. Sirtuin 1 (SIRT1) has roles in cellular aging, antioxidant activity, cellular proliferation. In an experimental study, inhibition of SIRT1 was found to delay renal cyst development in ADPKD. The purpose of this study is to determine the SIRT1 levels in ADPKD patients. To our knowledge, this is the first study that investigating blood and urine SIRT1 levels in ADPKD patients.
METHODS: Sixty-seven patients with ADPKD and 34 control cases with normal renal functions and without renal cysts were included in this study. Serum and urine SIRT1 concentrations were determined by human enzyme-linked immunosorbent assay (ELISA) kit. 24-h urine samples were used for urine SIRT1 measurements.
RESULTS: The urine SIRT1 levels were statistically significantly lower in ADPKD patients group (p < 0.001). Although blood SIRT1 levels of ADPKD patients were higher than control cases but there were no statistically significant difference between the groups in terms of blood SIRT1 levels. Urine SIRT1 levels (β = 2.452, CI 95% 1.419-4.239, p = 0.001) were found an independent factor in multivariate regression analysis for ADPKD.
CONCLUSIONS: Urine SIRT1 levels were lower in ADPKD patients than control group. The low urinary SIRT1 levels despite the similar blood SIRT1 levels might be due to the impaired metabolism of SIRT1 in ADPKD patients; this state might has a role in cyst development.

Keywords:  Polycystic kidney disease; Sirtuin 1; Urine SIRT1 levels

DOI:  https://doi.org/10.1007/s11255-021-02862-2
Gene. 2021 Apr 09. pii: S0378-1119(21)00234-1. [Epub ahead of print] 145640

CRISPR/Cas9-mediated mutagenesis reveals the roles of Calaxin in gastropod larval cilia.

Pin Huan, Menglu Cui, Qian Wang, Baozhong Liu.

  Obtaining detectable knockout phenotypes in the G0 generation is essential for gene function studies. Although CRISPR/Cas9-mediated gene editing has been employed to knock out molluscan genes, detectable phenotypes in the G0 generation have not been reported in these animals. In this study, we determined the knockout phenotype of a cilium-related gene, calaxin, using CRISPR/Cas9 technology in the gastropod mollusk Lottia goshimai. Injections with the Cas9-sgRNA complex caused approximately 30-80% of the injected larvae to exhibit a short-cilia phenotype characteristic of shortened cilia and decreased motility in the larvae. This phenotype was detectable in the G0 generation and was consistent for two independent sgRNAs. Genotyping of the injected larvae revealed various types of deletions and insertions in the target gene, which occurred in all sequences from the short-cilia larvae. This result indicated that the short-cilia phenotype was indeed caused by calaxin knockout. This possibility was supported by an RNAi assay targeting calaxin, which produced a highly similar short-cilia phenotype. We observed that a single SNP in the target sequences of the sgRNAs could show varied effects on the efficiency of mutagenesis. These results help to establish a foundation for future studies on molluscan gene editing using the CRISPR/Cas9 technique and contribute to the body of knowledge on molluscan ciliary functions.

Keywords:  CRISPR/Cas9; calaxin; gene editing; mollusk

DOI:  https://doi.org/10.1016/j.gene.2021.145640
Cell Calcium. 2021 Apr 08. pii: S0143-4160(21)00060-9. [Epub ahead of print]96 102406

Attenuation of the extracellular matrix increases the number of synapses but suppresses synaptic plasticity through upregulation of SK channels.

Yulia Dembitskaya, Nikolay Gavrilov, Igor Kraev, Maxim Doronin, Yong Tang, Li Li, Alexey Semyanov.

  The effect of brain extracellular matrix (ECM) on synaptic plasticity remains controversial. Here, we show that targeted enzymatic attenuation with chondroitinase ABC (ChABC) of ECM triggers the appearance of new glutamatergic synapses on hippocampal pyramidal neurons, thereby increasing the amplitude of field EPSPs while decreasing both the mean miniature EPSC amplitude and AMPA/NMDA ratio. Although the increased proportion of 'unpotentiated' synapses caused by ECM attenuation should promote long-term potentiation (LTP), surprisingly, LTP was suppressed. The upregulation of small conductance Ca2+-activated K+ (SK) channels decreased the excitability of pyramidal neurons, thereby suppressing LTP. A blockade of SK channels restored cell excitability and enhanced LTP; this enhancement was abolished by a blockade of Rho-associated protein kinase (ROCK), which is involved in the maturation of dendritic spines. Thus, targeting ECM elicits the appearance of new synapses, which can have potential applications in regenerative medicine. However, this process is compensated for by a reduction in postsynaptic neuron excitability, preventing network overexcitation at the expense of synaptic plasticity.

Keywords:  Dendritic spine; Extracellular matrix; LTP; SK channel

DOI:  https://doi.org/10.1016/j.ceca.2021.102406
Cell Mol Life Sci. 2021 Apr 15.

Moonlighting of mitotic regulators in cilium disassembly.

Cenna Doornbos, Ronald Roepman.

  Correct timing of cellular processes is essential during embryological development and to maintain the balance between healthy proliferation and tumour formation. Assembly and disassembly of the primary cilium, the cell's sensory signalling organelle, are linked to cell cycle timing in the same manner as spindle pole assembly and chromosome segregation. Mitotic processes, ciliary assembly, and ciliary disassembly depend on the centrioles as microtubule-organizing centres (MTOC) to regulate polymerizing and depolymerizing microtubules. Subsequently, other functional protein modules are gathered to potentiate specific protein-protein interactions. In this review, we show that a significant subset of key mitotic regulator proteins is moonlighting at the cilium, among which PLK1, AURKA, CDC20, and their regulators. Although ciliary assembly defects are linked to a variety of ciliopathies, ciliary disassembly defects are more often linked to brain development and tumour formation. Acquiring a better understanding of the overlap in regulators of ciliary disassembly and mitosis is essential in finding therapeutic targets for the different diseases and types of tumours associated with these regulators.

Keywords:  Cell cycle regulators; Centrioles; Cilia; Cilium resorption; Tumour development; WNT

DOI:  https://doi.org/10.1007/s00018-021-03827-5
Invest Ophthalmol Vis Sci. 2021 Apr 01. 62(4): 21

Effectively Intervening Epithelial-Mesenchymal Transition of Retinal Pigment Epithelial Cells With a Combination of ROCK and TGF-β Signaling Inhibitors.

Yi Chen, Binxin Wu, Jian Feng He, Jingyao Chen, Zi Wei Kang, Dandan Liu, Junjie Luo, Kexin Fang, Xiaoxu Leng, Haibin Tian, Jingying Xu, Caixia Jin, Jieping Zhang, Juan Wang, Jingfa Zhang, Qingjian Ou, Lixia Lu, Furong Gao, Guo-Tong Xu.

Purpose: Epithelial-mesenchymal transition (EMT) of retinal pigment epithelial (RPE) cells is a key pathological event in proliferative retinal diseases such as proliferative vitreoretinopathy (PVR). This study aimed to explore a new method to reverse EMT in RPE cells to develop an improved therapy for proliferative retinal diseases.
Methods: In vitro, human embryonic stem cell-derived RPE cells were passaged and cultured at low density for an extended period of time to establish an EMT model. At different stages of EMT after treatment with known molecules or combinations of molecules, the morphology was examined, transepithelial electrical resistance (TER) was measured, and expression of RPE- and EMT-related genes were examined with RT-PCR, Western blotting, and immunofluorescence. In vivo, a rat model of EMT in RPE cells was established via subretinal injection of dispase. Retinal function was examined by electroretinography (ERG), and retinal morphology was examined.
Results: EMT of RPE cells was effectively induced by prolonged low-density culture. After EMT occurred, only the combination of the Rho-associated coiled-coil containing protein kinase (ROCK) inhibitor Y27632 and the TGF-β receptor inhibitor RepSox (RY treatment) effectively suppressed and reversed the EMT process, even in cells in an intermediate state of EMT. In dispase-treated Sprague-Dawley rats, RY treatment maintained the morphology of RPE cells and the retina and preserved retinal function.
Conclusions: RY treatment might promote mesenchymal-epithelial transition (MET), the inverse process of EMT, to maintain the epithelial-like morphology and function of RPE cells. This combined RY therapy could be a new strategy for treating proliferative retinal diseases, especially those involving EMT of RPE cells.

DOI: https://doi.org/10.1167/iovs.62.4.21
Orphanet J Rare Dis. 2021 Apr 14. 16(1): 179

A ZFYVE19 gene mutation associated with neonatal cholestasis and cilia dysfunction: case report with a novel pathogenic variant.

Claudia Mandato, Maria Anna Siano, Lucia Nazzaro, Monica Gelzo, Paola Francalanci, Francesca Rizzo, Ylenia D'Agostino, Manuela Morleo, Simona Brillante, Alessandro Weisz, Brunella Franco, Pietro Vajro.

   BACKGROUND: ZFYVE19 (Zinc Finger FYVE-Type Containing 19) mutations have most recently been associated to a novel type of high gamma-glutamyl transpeptidase (GGT), non-syndromic, neonatal-onset intrahepatic chronic cholestasis possibly associated to cilia dysfunction. Herein, we report a new case with further studies of whole exome sequencing (WES) and immunofluorescence in primary cilia of her cultured fibroblasts which confirm the observation.
RESULTS: A now 5-year-old girl born to clinically healthy consanguineous Moroccan parents was assessed at 59 days of life due to severe cholestatic jaundice with increased serum bile acids and GGT, and preserved hepatocellular synthetic function. Despite fibrosis/cirrhosis and biliary ducts proliferation on liver biopsy suggested an extrahepatic biliary obstacle, normal intra-operatory cholangiography excluded biliary atresia. Under choleretic treatment, she maintained a clinically stable anicteric cholestasis but developped hyperlipidemia. After exclusion of the main causes of cholestasis by multiple tests, abnormal concentrations of sterols and WES led to a diagnosis of hereditary sitosterolemia (OMIM #618666), likely unrelated to her cholestasis. Further sequencing investigation revealed a homozygous non-sense mutation (p.Arg223Ter) in ZFYVE19 leading to a 222 aa truncated protein and present in both heterozygous parents. Immunofluorescence analysis of primary cilia on cultured skin fibroblasts showed a ciliary phenotype mainly defined by fragmented cilia and centrioles abnormalities.
CONCLUSIONS: Our findings are consistent with and expands the recent evidence linking ZFYVE19 to a novel, likely non-syndromic, high GGT-PFIC phenotype with neonatal onset. Due to the possible role of ZFYVE19 in cilia function and the unprecedented coexistence of a coincidental hereditary sterol disorder in our case, continuous monitoring will be necessary to substantiate type of liver disease progression and/or possible emergence of a multisystemic involvement. What mentioned above confirms that the application of WES in children with undiagnosed cholestasis may lead to the identification of new causative genes, widening the knowledge on the pathophysiology.

Keywords:  Children; Cholestasis; Ciliopathy; ZFYVE19

DOI:  https://doi.org/10.1186/s13023-021-01775-8
BMC Pregnancy Childbirth. 2021 Apr 12. 21(1): 294

Imaging manifestations of Caroli disease with autosomal recessive polycystic kidney disease: a case report and literature review.

Xiuzhen Yao, Weiqun Ao, Jianhua Fang, Guoqun Mao, Chuanghua Chen, Lifang Yu, Huaijie Cai, Chenke Xu.

   BACKGROUND: Both Caroli disease (CD) and autosomal recessive polycystic kidney disease (ARPKD) are autosomal recessive disorders, which are more commonly found in infants and children, for whom surviving to adulthood is rare. Early diagnosis and intervention can improve the survival rate to some extent. This study adopted the case of a 26-year-old pregnant woman to explore the clinical and imaging manifestations and progress of CD concomitant with ARPKD to enable a better understanding of the disease.
CASE PRESENTATION: A 26-year-old pregnant woman was admitted to our hospital for more than 2 months following the discovery of pancytopenia and increased creatinine. Ultrasonography detected an enlarged left liver lobe, widened hepatic portal vein, splenomegaly, and dilated splenic vein. In addition, both kidneys were obviously enlarged and sonolucent areas of varying sizes were visible, but color Doppler flow imaging revealed no abnormal blood flow signals. The gestational age was approximately 25 weeks, which was consistent with the actual fetal age. Polyhydramnios was detected but no other abnormalities were identified. Magnetic resonance imaging revealed that the liver was plump, and polycystic liver disease was observed near the top of the diaphragm. The T1 and T2 weighted images were the low and high signals, respectively. The bile duct was slightly dilated; the portal vein was widened; and the spleen volume was enlarged. Moreover, the volume of both kidneys had increased to an abnormal shape, with multiple, long, roundish T1 and T2 abnormal signals being observed. Magnetic resonance cholangiopancreatography revealed that intrahepatic cystic lesions were connected with intrahepatic bile ducts. The patient underwent a genetic testing, the result showed she carried two heterozygous mutations in PKHD1. The patient was finally diagnosed with CD with concomitant ARPKD. The baby underwent a genetic test three months after birth, the result showed that the patient carried one heterozygous mutations in PKHD1, which indicated the baby was a PKHD1 carrier.
CONCLUSIONS: This case demonstrates that imaging examinations are of great significance for the diagnosis and evaluation of CD with concomitant ARPKD.

Keywords:  Autosomal recessive polycystic kidney disease; Caroli disease; Diagnosis; Magnetic resonance imaging; Ultrasound

DOI:  https://doi.org/10.1186/s12884-021-03768-8
Sci Rep. 2021 Apr 12. 11(1): 7899

STORM imaging reveals the spatial arrangement of transition zone components and IFT particles at the ciliary base in Tetrahymena.

Khodor S Hazime, Zhu Zhou, Ewa Joachimiak, Natalia A Bulgakova, Dorota Wloga, Jarema J Malicki.

The base of the cilium comprising the transition zone (TZ) and transition fibers (TF) acts as a selecting gate to regulate the intraflagellar transport (IFT)-dependent trafficking of proteins to and from cilia. Before entering the ciliary compartment, IFT complexes and transported cargoes accumulate at or near the base of the cilium. The spatial organization of IFT proteins at the cilia base is key for understanding cilia formation and function. Using stochastic optical reconstruction microscopy (STORM) and computational averaging, we show that seven TZ, nine IFT, three Bardet-Biedl syndrome (BBS), and one centrosomal protein, form 9-clustered rings at the cilium base of a ciliate Tetrahymena thermophila. In the axial dimension, analyzed TZ proteins localize to a narrow region of about 30 nm while IFT proteins dock approximately 80 nm proximal to TZ. Moreover, the IFT-A subcomplex is positioned peripheral to the IFT-B subcomplex and the investigated BBS proteins localize near the ciliary membrane. The positioning of the HA-tagged N- and C-termini of the selected proteins enabled the prediction of the spatial orientation of protein particles and likely cargo interaction sites. Based on the obtained data, we built a comprehensive 3D-model showing the arrangement of the investigated ciliary proteins.

DOI: https://doi.org/10.1038/s41598-021-86909-5
Cell Signal. 2021 Apr 13. pii: S0898-6568(21)00095-4. [Epub ahead of print]84 110007

The implication of ROCK 2 as a potential senotherapeutic target via the suppression of the harmful effects of the SASP: Do senescent cancer cells really engulf the other cells?

Yaprak Dilber Şimay Demir, Aysun Özdemir, Ceren Sucularlı, Elifnur Benhür, Mustafa Ark.

  Chemotherapy-induced senescent cancer cells secrete several factors in their microenvironment called SASP. Accumulated evidence states that SASP is responsible for some of the harmful effects of chemotherapy such as drug resistance and the induction of cancer cell proliferation, migration, and invasion. Therefore, to develop senolytic and/or senomorphic drugs, targeting the senescent cells gains importance as a new strategy for preventing the damage that senescent cancer cells cause. In the current work, we evaluated whether Rho/Rho kinase pathway has the potential to be used as a target pathway for the development of senolytic and/or senomorphic drugs in doxorubicin-induced senescent cancer cell lines. We have determined that inhibition of Rho/Rho kinase pathway with CT04 and Y27632 reduced the secretory activity of senescent cancer cells and changed the composition of SASP. Our results indicate that ROCK 2 isoform was responsible for these observed effects on the SASP. In addition, non-senescent cancer cell proliferation and migration accelerated by senescent cells were set back to the pre-induction levels after ROCK inhibition. Moreover, contrary to the previous observations, another important finding of the current work is that senescent HeLa and A549 cells did not engulf the non-senescent HeLa, A549 cells, and non-cancer HUVEC. These results indicate that ROCK inhibitors, in particular ROCK 2 specific inhibitors, have the potential to be developed as novel senomorphic drugs. In addition, we found that all senescent cancer cells do not share the same engulfment ability, and this process should not be generalized.

Keywords:  Chemotherapy-induced senescence; Rho/ROCK pathway; Senescence-associated secretory phenotype; Senescent cell secretome; Senotherapeutic

DOI:  https://doi.org/10.1016/j.cellsig.2021.110007
Biochem Soc Trans. 2021 Apr 12. pii: BST20200751. [Epub ahead of print]

Primary cilia and the DNA damage response: linking a cellular antenna and nuclear signals.

Ciaran G Morrison.

  The maintenance of genome stability involves integrated biochemical activities that detect DNA damage or incomplete replication, delay the cell cycle, and direct DNA repair activities on the affected chromatin. These processes, collectively termed the DNA damage response (DDR), are crucial for cell survival and to avoid disease, particularly cancer. Recent work has highlighted links between the DDR and the primary cilium, an antenna-like, microtubule-based signalling structure that extends from a centriole docked at the cell surface. Ciliary dysfunction gives rise to a range of complex human developmental disorders termed the ciliopathies. Mutations in ciliopathy genes have been shown to impact on several functions that relate to centrosome integrity, DNA damage signalling, responses to problems in DNA replication and the control of gene expression. This review covers recent findings that link cilia and the DDR and explores the various roles played by key genes in these two contexts. It outlines how proteins encoded by ciliary genes impact checkpoint signalling, DNA replication and repair, gene expression and chromatin remodelling. It discusses how these diverse activities may integrate nuclear responses with those that affect a structure of the cell periphery. Additional directions for exploration of the interplay between these pathways are highlighted, with a focus on new ciliary gene candidates that alter genome stability.

Keywords:  DNA synthesis and repair; cell cycle; centrosomes; cilia

DOI:  https://doi.org/10.1042/BST20200751
Cell Tissue Res. 2021 Apr 16.

BBS4 protein has basal body/ciliary localization in sensory organs but extra-ciliary localization in oligodendrocytes during human development.

K Bénardais, G Delfino, B Samama, D Devys, M C Antal, M S Ghandour, N Boehm.

  Bardet-Biedl syndrome protein 4 (BBS4) localization has been studied in human embryos/fetuses from Carnegie stage 15 to 37 gestational weeks in neurosensory organs and brain, underlying the major clinical signs of BBS. We observed a correlation between the differentiation of the neurosensory cells (hair cells, photoreceptors, olfactory neurons) and the presence of a punctate BBS4 immunostaining in their apical cytoplasm. In the brain, BBS4 was localized in oligodendrocytes and myelinated tracts. In individual myelinated fibers, BBS4 immunolabelling was discontinuous, predominantly at the periphery of the myelin sheath. BBS4 immunolabelling was confirmed in postnatal developing white matter tracts in mouse as well as in mouse oligodendrocytes cultures. In neuroblasts/neurons, BBS4 was only present in reelin-expressing Cajal-Retzius cells. Our results show that BBS4, a protein of the BBSome, has both basal body/ciliary localization in neurosensory organs but extra-ciliary localization in oligodendrocytes. The presence of BBS4 in developing oligodendrocytes and myelin described in the present paper might attribute a new role to this protein, requiring further investigation in the field of myelin formation.

Keywords:  BBS4; Development; Human; Immunostaining; Oligodendrocyte

DOI:  https://doi.org/10.1007/s00441-021-03440-9
Mol Biol Cell. 2021 Apr 14. mbcE20120806

Structural insights into the cause of human RSPH4A primary ciliary dyskinesia.

Yanhe Zhao, Justine Pinskey, Jianfeng Lin, Weining Yin, Patrick R Sears, Leigh A Daniels, Maimoona A Zariwala, Michael R Knowles, Lawrence E Ostrowski, Daniela Nicastro.

Cilia and flagella are evolutionarily conserved eukaryotic organelles involved in cell motility and signaling. In humans, mutations in Radial Spoke Head Protein 4 homolog A (RSPH4A) can lead to primary ciliary dyskinesia (PCD), a life-shortening disease characterized by chronic respiratory tract infections, abnormal organ positioning, and infertility. Despite its importance for human health, the location of RSPH4A in human cilia has not been resolved, and the structural basis of RSPH4A-/- PCD remains elusive. Here, we present the native, three-dimensional structure of RSPH4A-/- human respiratory cilia using samples collected non-invasively from a PCD patient. Using cryo-electron tomography and subtomogram averaging, we compared the structures of control and RSPH4A-/- cilia, revealing primary defects in two of the three radial spokes (RSs) within the axonemal repeat and secondary (heterogeneous) defects in the central pair complex. Similar to RSPH1-/- cilia, the radial spoke heads of RS1 and RS2, but not RS3, were missing in RSPH4A-/- cilia. However, RSPH4A-/- cilia also exhibited defects within the arch domains adjacent to the RS1 and RS2 heads, which were not observed with RSPH1 loss. Our results provide insight into the underlying structural basis for RSPH4A-/- PCD and highlight the benefits of applying cryo-ET directly to patient samples for molecular structure determination. [Media: see text].

DOI: https://doi.org/10.1091/mbc.E20-12-0806
Adv Sci (Weinh). 2021 Apr;8(7): 2002112

Modulating the Electrical and Mechanical Microenvironment to Guide Neuronal Stem Cell Differentiation.

Byeongtaek Oh, Yu-Wei Wu, Vishal Swaminathan, Vivek Lam, Jun Ding, Paul M George.

  The application of induced pluripotent stem cells (iPSCs) in disease modeling and regenerative medicine can be limited by the prolonged times required for functional human neuronal differentiation and traditional 2D culture techniques. Here, a conductive graphene scaffold (CGS) to modulate mechanical and electrical signals to promote human iPSC-derived neurons is presented. The soft CGS with cortex-like stiffness (≈3 kPa) and electrical stimulation (±800 mV/100 Hz for 1 h) incurs a fivefold improvement in the rate (14d) of generating iPSC-derived neurons over some traditional protocols, with an increase in mature cellular markers and electrophysiological characteristics. Consistent with other culture conditions, it is found that the pro-neurogenic effects of mechanical and electrical stimuli rely on RhoA/ROCK signaling and de novo ciliary neurotrophic factor (CNTF) production respectively. Thus, the CGS system creates a combined physical and continuously modifiable, electrical niche to efficiently and quickly generate iPSC-derived neurons.

Keywords:  cell scaffolds; ciliary neurotrophic factor; conductive polymers; electrical stimulation; electrophysiology; graphene; stem cells

DOI:  https://doi.org/10.1002/advs.202002112
G Ital Nefrol. 2021 Apr 14. pii: 2021-vol2. [Epub ahead of print]38(2):

[Phosphorus binders: trigger for intestinal diverticula formation in an ADPKD patient].

Maurizio Garozzo, Concetta Luisa Monica Gullè, Anna Clementi, Filippo Milone, Giovanni Giorgio Battaglia.

Hyperphosphoremia is common in patients with chronic kidney disease and is an important risk factor in this patient population. Phosphate binding drugs are a key therapeutic strategy to reduce phosphoremia levels, although they have significant side effects especially in the gastrointestinal tract, such as gastritis, diarrhoea and constipation. We report the case of a haemodialysis-dependent patient suffering from chronic kidney disease stage V KDIGO secondary to polycystic autosomal dominant disease; treated with phosphate binders, the case was complicated by the appearance of diverticulosis, evolved into acute diverticulitis.

Keywords: acute diverticulitis; chronic kidney disease; diverticulosis; hyperphosphoremia; phosphate binding drugs; polycystic autosomal dominant disease
Front Cell Dev Biol. 2021 ;9 658006

ARHGEF18/p114RhoGEF Coordinates PKA/CREB Signaling and Actomyosin Remodeling to Promote Trophoblast Cell-Cell Fusion During Placenta Morphogenesis.

Robert Beal, Ana Alonso-Carriazo Fernandez, Dimitris K Grammatopoulos, Karl Matter, Maria S Balda.

  Coordination of cell-cell adhesion, actomyosin dynamics and gene expression is crucial for morphogenetic processes underlying tissue and organ development. Rho GTPases are main regulators of the cytoskeleton and adhesion. They are activated by guanine nucleotide exchange factors in a spatially and temporally controlled manner. However, the roles of these Rho GTPase activators during complex developmental processes are still poorly understood. ARHGEF18/p114RhoGEF is a tight junction-associated RhoA activator that forms complexes with myosin II, and regulates actomyosin contractility. Here we show that p114RhoGEF/ARHGEF18 is required for mouse syncytiotrophoblast differentiation and placenta development. In vitro and in vivo experiments identify that p114RhoGEF controls expression of AKAP12, a protein regulating protein kinase A (PKA) signaling, and is required for PKA-induced actomyosin remodeling, cAMP-responsive element binding protein (CREB)-driven gene expression of proteins required for trophoblast differentiation, and, hence, trophoblast cell-cell fusion. Our data thus indicate that p114RhoGEF links actomyosin dynamics and cell-cell junctions to PKA/CREB signaling, gene expression and cell-cell fusion.

Keywords:  AKAP12; ARHGEF18; CREB; RhoA; cell-cell adhesion; trophoblasts

DOI:  https://doi.org/10.3389/fcell.2021.658006
Mol Neurobiol. 2021 Apr 15.

Semaphorin3F Drives Dendritic Spine Pruning Through Rho-GTPase Signaling.

Bryce W Duncan, Vishwa Mohan, Sarah D Wade, Young Truong, Alexander Kampov-Polevoi, Brenda R Temple, Patricia F Maness.

  Dendritic spines of cortical pyramidal neurons are initially overproduced then remodeled substantially in the adolescent brain to achieve appropriate excitatory balance in mature circuits. Here we investigated the molecular mechanism of developmental spine pruning by Semaphorin 3F (Sema3F) and its holoreceptor complex, which consists of immunoglobulin-class adhesion molecule NrCAM, Neuropilin-2 (Npn2), and PlexinA3 (PlexA3) signaling subunits. Structure-function studies of the NrCAM-Npn2 interface showed that NrCAM stabilizes binding between Npn2 and PlexA3 necessary for Sema3F-induced spine pruning. Using a mouse neuronal culture system, we identified a dual signaling pathway for Sema3F-induced pruning, which involves activation of Tiam1-Rac1-PAK1-3 -LIMK1/2-Cofilin1 and RhoA-ROCK1/2-Myosin II in dendritic spines. Inhibitors of actin remodeling impaired spine collapse in the cortical neurons. Elucidation of these pathways expands our understanding of critical events that sculpt neuronal networks and may provide insight into how interruptions to these pathways could lead to spine dysgenesis in diseases such as autism, bipolar disorder, and schizophrenia.

Keywords:  Actin cytoskeleton; Cell adhesion molecules; Cortical neurons; Dendritic spines; Semaphorins; Signal transduction; Spine pruning

DOI:  https://doi.org/10.1007/s12035-021-02373-2