bims-bicyki Biomed News
on Bicaudal-C1 and interactors in cystic kidney disease
Issue of 2021‒01‒31
sixteen papers selected by
Céline Gagnieux
École Polytechnique Fédérale de Lausanne (EPFL)

  1. Pediatr Nephrol. 2021 Jan 27.
      Autosomal dominant polycystic kidney disease (ADPKD) is associated with distinct cytopenias in observational studies; the most consistent and strongest association is seen with alternations in the lymphocytic lineages. Although the underlying mechanism of these associations is unclear, it has been hypothesized to be secondary to sequestration of white blood cells in cystic organs, or related to the uremic environment in chronic kidney disease (CKD). However, since mutations in PKD1 or -2 affect several immunomodulating pathways, cytopenia may well be an unrecognized extrarenal manifestation of ADPKD. Furthermore, many important questions on the clinical implications of this finding and the effect on the disease course in these patients are unanswered. In this review article, we provide an overview of the current evidence on cytopenia in ADPKD and explore the underlying mechanisms of this association and its potential prognostic implications. Based on the current literature, we hypothesize that polycystin deficiency can disturb immune cell homeostasis and that cytopenia is thus an intrinsic feature of ADPKD, related to genetic factors. Taken together, these findings warrant further investigation to establish the exact etiology and role of cytopenia in patients with ADPKD.
    Keywords:  ADPKD; CKD; Ciliopathies; Leukopenia; Lymphopenia
  2. Exp Clin Transplant. 2021 Jan 26.
      Autosomal dominant polycystic kidney disease is the fourth most common single cause of end-stage renal disease worldwide with both renal and extrarenal manifestations, resulting in significant morbidity. Approaches to the management of this disease vary widely, with no broadly accepted practice guidelines. Herein, we reviewed the various surgical and interventional management options that are targeted toward treating the symptoms or addressing the resulting kidney failure. Novel treatment modalities such as celiac plexus blockade and renal denervation appear to be promising in pain relief; however, further studies are lacking. Renal cyst decortication seems to have a higher success rate in targeting cyst-related pain compared with aspiration only. In terms of requiring major surgical intervention, such as need and timing of native nephrectomy, there are several considerations when deciding on transplantation with or without a pretransplant native nephrectomy. Patients who are not candidates for native nephrectomy may consider transcatheter arterial embolization. Based on our review of the contemporary indications for genitourinary interventions in the management of autosomal dominant polycystic kidney disease, we propose an algorithm that depicts the decision-making process on assessing the indications and timing of native nephrectomy in patients with end-stage renal disease awaiting transplant.
  3. Nat Commun. 2021 01 28. 12(1): 662
      Dynamic assembly and disassembly of primary cilia controls embryonic development and tissue homeostasis. Dysregulation of ciliogenesis causes human developmental diseases termed ciliopathies. Cell-intrinsic regulatory mechanisms of cilia disassembly have been well-studied. The extracellular cues controlling cilia disassembly remain elusive, however. Here, we show that lysophosphatidic acid (LPA), a multifunctional bioactive phospholipid, acts as a physiological extracellular factor to initiate cilia disassembly and promote neurogenesis. Through systematic analysis of serum components, we identify a small molecular-LPA as the major driver of cilia disassembly. Genetic inactivation and pharmacological inhibition of LPA receptor 1 (LPAR1) abrogate cilia disassembly triggered by serum. The LPA-LPAR-G-protein pathway promotes the transcription and phosphorylation of cilia disassembly factors-Aurora A, through activating the transcription coactivators YAP/TAZ and calcium/CaM pathway, respectively. Deletion of Lpar1 in mice causes abnormally elongated cilia and decreased proliferation in neural progenitor cells, thereby resulting in defective neurogenesis. Collectively, our findings establish LPA as a physiological initiator of cilia disassembly and suggest targeting the metabolism of LPA and the LPA pathway as potential therapies for diseases with dysfunctional ciliogenesis.
  4. Mol Med Rep. 2021 Mar;pii: 195. [Epub ahead of print]23(3):
      Autosomal dominant polycystic kidney disease (ADPKD), a common disease with a high incidence ratio of between 1/400 and 1/1,000 individuals, often results in kidney failure and even mortality. However, there are relatively few effective treatments available, and treatment is limited to lifelong hemodialysis or kidney transplant. Our previous studies have reported that curcumin (Cur) and ginkgolide B (GB) inhibited cystogenesis by regulating the Ras/ERK MAPK signaling pathway. In the present study, it was hypothesized that Cur and GB may have a synergistic effect on the inhibition of cystogenesis, and their synergistic effect may be the result of regulation of multiple signaling pathways. To assess this hypothesis, an in vitro Madin‑Darby canine kidney (MDCK) cyst model and an in vivo kidney‑specific polycystin 1 transient receptor potential channel interacting (Pkd1) knockout mouse model were established to observe the effects of the combination of Cur and GB. The cysts exposed to Cur, GB and Cur combined with GB became small thick‑walled cysts, small thin‑walled cysts and round shaped cell colonies, respectively. The combination of Cur and GB was more effective compared with either treatment alone in inhibiting cystogenesis. Additionally, to the best of our knowledge, the present study was the first to demonstrate the synergistic effect of Cur and GB on the inhibition of cystogenesis in Pkd1 knockout mice. Cur may have mediated its anti‑cyst effects by blocking EGFR/ERK1/2, JNK and PI3K/mTOR signaling pathways, while GB may have inhibited cystogenesis via the downregulation of the EGFR/ERK1/2, JNK and p38 signaling pathways. These results provide a proof‑of‑concept for application of the combination of Cur and GB in inhibiting cystogenesis in ADPKD.
  5. Iran J Kidney Dis. 2021 Jan;1(1): 61-63
      Renal lymphangiomatosis is an unusual disorder. It may develop due to the abnormality of the intrarenal, peripelvic and perirenal lymphatics. The differential diagnosis contains renal lymphoma, polycystic kidney disease, multicystic dysplasia and renal tumors. We report a case of renal lymphangiomatosis, previously diagnosed as autosomal dominant polycystic kidney disease, to emphasize that these two diseases can be easily confused. It should be kept in mind that RL is in the differential diagnosis of polycystic renal disease to prevent overtreatment.
  6. Open Biol. 2021 Jan;11(1): 200283
      Precision genomic alterations largely rely on homology directed repair (HDR), but targeting without homology using the non-homologous end-joining (NHEJ) pathway has gained attention as a promising alternative. Previous studies demonstrated precise insertions formed by the ligation of donor DNA into a targeted genomic double-strand break in both dividing and non-dividing cells. Here, we demonstrate the use of NHEJ repair to replace genomic segments with donor sequences; we name this method 'Replace' editing (Rational end-joining protocol delivering a targeted sequence exchange). Using CRISPR/Cas9, we create two genomic breaks and ligate a donor sequence in-between. This exchange of a genomic for a donor sequence uses neither microhomology nor homology arms. We target four loci in cell lines and show successful exchange of exons in 16-54% of human cells. Using linear amplification methods and deep sequencing, we quantify the diversity of outcomes following Replace editing and profile the ligated interfaces. The ability to replace exons or other genomic sequences in cells not efficiently modified by HDR holds promise for both basic research and medicine.
    Keywords:  CRISPR; exon replacement; gene editing; replace editing
  7. Nat Commun. 2021 01 27. 12(1): 612
      The motile cilia of ependymal cells coordinate their beats to facilitate a forceful and directed flow of cerebrospinal fluid (CSF). Each cilium originates from a basal body with a basal foot protruding from one side. A uniform alignment of these basal feet is crucial for the coordination of ciliary beating. The process by which the basal foot originates from subdistal appendages of the basal body, however, is unresolved. Here, we show FGFR1 Oncogene Partner (FOP) is a useful marker for delineating the transformation of a circular, unpolarized subdistal appendage into a polarized structure with a basal foot. Ankyrin repeat and SAM domain-containing protein 1A (ANKS1A) interacts with FOP to assemble region I of the basal foot. Importantly, disruption of ANKS1A reduces the size of region I. This produces an unstable basal foot, which disrupts rotational polarity and the coordinated beating of cilia in young adult mice. ANKS1A deficiency also leads to severe degeneration of the basal foot in aged mice and the detachment of cilia from their basal bodies. This role of ANKS1A in the polarization of the basal foot is evolutionarily conserved in vertebrates. Thus, ANKS1A regulates FOP to build and maintain the polarity of subdistal appendages.
  8. Front Cell Dev Biol. 2020 ;8 616762
      The rho-associated coiled-coil-containing proteins (ROCKs or rho kinase) are effectors of the small rho-GTPase rhoA, which acts as a signaling molecule to regulate a variety of cellular processes, including cell proliferation, adhesion, polarity, cytokinesis, and survival. Owing to the multifunctionality of these kinases, an increasing number of studies focus on understanding the pleiotropic effects of the ROCK signaling pathway in the coordination and control of growth (proliferation, initiation, and progression), development (morphology and differentiation), and survival in many cell types. There is growing evidence that ROCKs actively phosphorylate several actin-binding proteins and intermediate filament proteins during oocyte cytokinesis, the preimplantation embryos as well as the stem cell development and differentiation. In this review, we focus on the participation of ROCK proteins in oocyte maturation, blastocyst formation, and stem cell development with a special focus on the selective targeting of ROCK isoforms, ROCK1, and ROCK2. The selective switching of cell fate through ROCK inhibition would provide a novel paradigm for in vitro oocyte maturation, experimental embryology, and clinical applications.
    Keywords:  actin; differentiation; oocyte; rho kinase; stem cells
  9. Histochem Cell Biol. 2021 Jan 25.
      Urothelial bladder cancer is the tenth most common cancer worldwide. It is divided into muscle and non-muscle invading bladder cancer. Primary cilia have been related to several cancer hallmarks such as proliferation, epithelial-to-mesenchymal transition (EMT) or tumoral progression mainly through signaling pathways as Hedgehog (Hh). In the present study, we used immunohistochemical and ultrastructural techniques in human tissues of healthy bladder, non-muscle-invasive bladder cancer (NMIBC) and muscle-invasive bladder cancer (MIBC) to study and clarify the activation of epithelial-to-mesenchymal transition and Hedgehog signaling pathway and the presence of primary cilia. Thus, we found a clear correlation between EMT and Hedgehog activation and bladder cancer stage and progression. Moreover, we identified the presence of primary cilia in these tissues. Interestingly, we found that in NMIBC, some ciliated cells cross the basement membrane and localized in lamina propria, near blood vessels. These results show a correlation between EMT beginning from urothelial basal cells and primary cilia assembly and suggest a potential implication of this structure in tumoral migration and invasiveness (likely in a Hh-dependent way). Hence, primary cilia may play a fundamental role in urothelial bladder cancer progression and suppose a potential therapeutic target.
    Keywords:  Bladder cancer; Epithelial–mesenchymal transition; Hedeghog signalling pathway; Primary cilia; Transmission electron microscopy; Ultrastructure
  10. Biology (Basel). 2021 Jan 20. pii: E70. [Epub ahead of print]10(2):
      The small GTPase RhoA, and its down-stream effector ROCK kinase, and the interacting Rac1and and mTORC2 pathways, are the principal regulators of the actin cytoskeleton and actin-related functions in all eukaryotic cells, including the immune cells. As such, they also regulate the phenotypes and functions of macrophages in the immune response and beyond. Here, we review the results of our and other's studies on the role of the actin and RhoA pathway in shaping the macrophage functions in general and macrophage immune response during the development of chronic (long term) rejection of allografts in the rodent cardiac transplantation model. We focus on the importance of timing of the macrophage functions in chronic rejection and how the circadian rhythm may affect the anti-chronic rejection therapies.
    Keywords:  ROCK; Rac1; RhoA; actin; chronic rejection; circadian rhythm; macrophage; mouse; rat; timing; transplantation
  11. PLoS Pathog. 2021 Jan;17(1): e1008548
      Bartonellae are Gram-negative facultative-intracellular pathogens that use a type-IV-secretion system (T4SS) to translocate a cocktail of Bartonella effector proteins (Beps) into host cells to modulate diverse cellular functions. BepC was initially reported to act in concert with BepF in triggering major actin cytoskeletal rearrangements that result in the internalization of a large bacterial aggregate by the so-called 'invasome'. Later, infection studies with bepC deletion mutants and ectopic expression of BepC have implicated this effector in triggering an actin-dependent cell contractility phenotype characterized by fragmentation of migrating cells due to deficient rear detachment at the trailing edge, and BepE was shown to counterbalance this remarkable phenotype. However, the molecular mechanism of how BepC triggers cytoskeletal changes and the host factors involved remained elusive. Using infection assays, we show here that T4SS-mediated transfer of BepC is sufficient to trigger stress fiber formation in non-migrating epithelial cells and additionally cell fragmentation in migrating endothelial cells. Interactomic analysis revealed binding of BepC to a complex of the Rho guanine nucleotide exchange factor GEF-H1 and the serine/threonine-protein kinase MRCKα. Knock-out cell lines revealed that only GEF-H1 is required for mediating BepC-triggered stress fiber formation and inhibitor studies implicated activation of the RhoA/ROCK pathway downstream of GEF-H1. Ectopic co-expression of tagged versions of GEF-H1 and BepC truncations revealed that the C-terminal 'Bep intracellular delivery' (BID) domain facilitated anchorage of BepC to the plasma membrane, whereas the N-terminal 'filamentation induced by cAMP' (FIC) domain facilitated binding of GEF-H1. While FIC domains typically mediate post-translational modifications, most prominently AMPylation, a mutant with quadruple amino acid exchanges in the putative active site indicated that the BepC FIC domain acts in a non-catalytic manner to activate GEF-H1. Our data support a model in which BepC activates the RhoA/ROCK pathway by re-localization of GEF-H1 from microtubules to the plasma membrane.
  12. PLoS Pathog. 2021 Jan;17(1): e1009065
      Bartonella T4SS effector BepC was reported to mediate internalization of big Bartonella aggregates into host cells by modulating F-actin polymerization. After that, BepC was indicated to induce host cell fragmentation, an interesting cell phenotype that is characterized by failure of rear-end retraction during cell migration, and subsequent dragging and fragmentation of cells. Here, we found that expression of BepC resulted in significant stress fiber formation and contractile cell morphology, which depended on combination of the N-terminus FIC (filamentation induced by c-AMP) domain and C-terminus BID (Bartonella intracellular delivery) domain of BepC. The FIC domain played a key role in BepC-induced stress fiber formation and cell fragmentation because deletion of FIC signature motif or mutation of two conserved amino acid residues abolished BepC-induced cell fragmentation. Immunoprecipitation confirmed the interaction of BepC with GEF-H1 (a microtubule-associated RhoA guanosine exchange factor), and siRNA-mediated depletion of GEF-H1 prevented BepC-induced stress fiber formation. Interaction with BepC caused the dissociation of GEF-H1 from microtubules and activation of RhoA to induce formation of stress fibers. The ROCK (Rho-associated protein kinase) inhibitor Y27632 completely blocked BepC effects on stress fiber formation and cell contractility. Moreover, stress fiber formation by BepC increased the stability of focal adhesions, which consequently impeded rear-edge detachment. Overall, our study revealed that BepC-induced stress fiber formation was achieved through the GEF-H1/RhoA/ROCK pathway.
  13. Front Immunol. 2020 ;11 597775
      Accumulating evidence indicates that mammalian NIMA (never in mitosis, gene A)-related kinase 6 (NEK6) plays potential roles during the course of tumorigenesis, but little is known about NEK6 in lower vertebrates. Herein, we reported a mammalian ortholog of NEK6 in grass carp (Ctenopharyngodon idellus) (CiNEK6). Multiple alignment of amino acid sequences and phylogenetic analysis showed that CiNEK6 shares a high level of sequence similarity with its counterparts in birds. CiNEK6 was ubiquitously expressed in all tested tissues, and its expression level was increased under treatment with GCRV (dsRNA virus) or poly I:C (dsRNA analog). Q-PCR and dual-luciferase assays suggested that CiNEK6 overexpression suppressed IFN I activity in CIK cells treated with poly I:C. Knockdown of CiNEK6 resulted in a higher level of IFN I expression in CIK cells treated with poly I:C compared to those which received PBS. Interestingly, analysis of subcellular localization demonstrated that CiNEK6 protein scattered throughout the cytoplasm is gradually congregated together at the edges of karyotheca upon stimulation with poly I:C. Co-IP and co-localization assays suggested that CiNEK6 interacts with CiIRF3 after poly I:C challenge. In poly I:C-treated cells, the phosphorylation of CiIRF3 was increased by CiNEK6 knockdown, but was suppressed by CiNEK6 overexpression, suggesting that CiNEK6 decreases IFN I expression through inhibiting CiIRF3 activity. Cell viability assay, crystal violet staining, and detection of Vp5 also showed that CiNEK6 plays an inhibitory role in IRF3-mediated antiviral responses.
    Keywords:  IFN I; IRF3-mediated antiviral responses; NEK6; fish; inhibitor
  14. Mol Med Rep. 2021 Mar;pii: 194. [Epub ahead of print]23(3):
      The aim of the present study was to explore the effect of microRNA (miR)‑153 on the proliferation and migration of pulmonary artery smooth muscle cells (PASMCs) in a hypoxic condition by targeting ρ‑associated, coiled‑coil‑containing protein kinase 1 (ROCK1) and nuclear factor of activated T cells cytoplasmic 3 (NFATc3). The right ventricular systolic pressure, right ventricular hypertrophy index, medial wall thickness and medial wall area were studied at different time‑points after rats were exposed to hypoxia. Western blot analysis was used to detect ROCK1 and NFATc3 protein levels. In addition, reverse transcription‑quantitative (RT‑q) PCR was performed to confirm the mRNA levels of miR‑153, ROCK1 and NFATc3 in human (H)PASMCs under hypoxic conditions. Transfected cells were then used to evaluate the effect of miR‑153 on cell proliferation and migration abilities. The association between miR‑153 and ROCK1 or NFATc3 was identified through double luciferase assays. Hypoxia induced pulmonary vascular remodeling and pulmonary arterial hypertension, which resulted from the abnormal proliferation of HPASMCs. ROCK1 and NFATc3 were the target genes of miR‑153 and miR‑153 mimic inhibited the protein expressions of ROCK1 and NFATc3 in HPASMCs and further inhibited cell proliferation and migration under hypoxic conditions. By contrast, the miR‑153 inhibitor promoted the proliferation and migration of HPASMCs. miR‑153 regulated the proliferation and migration of HPASMCs under hypoxia by targeting ROCK1 and NFATc3.
  15. Int Immunopharmacol. 2021 Jan 25. pii: S1567-5769(20)33826-1. [Epub ahead of print]92 107358
      INF39 is a nontoxic, irreversible, acrylate-based NLRP3 inhibitor and a further optimization of ethyl 2-((2-chlorophenyl) hydroxyl) methyl) acrylate (INF4E). However, the detail mechanism and the direct target of its anti-inflammatory activity is not clear. Here, we show that INF39 is a specific inhibitor for NLRP3 inflammasome activation. INF39 specifically suppresses NLRP3 activation but not the NLRC4 or AIM2 inflammasomes. INF39 has no effect on K+ efflux, ROS generation or mitochondrial membrane potential, which are the upstream events of NLRP3 inflammasome activation. In addition, INF39 has no direct inhibitory effect on GSDMD, which is the downstream event of inflammasomes. More importantly, INF39 inhibits the interaction of NEK7-NLRP3, and subsequently inhibits interaction of NLRP3-NLRP3, NLRP3-ASC, ASC oligomerization and speckle formation. Altogether, our study unveils a deeper anti-inflammatory mechanism for INF39 and suggests it could serve as a lead for developing novel therapeutics combating NLRP3-driven diseases.
    Keywords:  Anti-inflammation; INF39; Inflammasome; NLRP3 inflammasome
  16. Theranostics. 2021 ;11(5): 2460-2474
      Rationale: Inflammatory stimuli from the tumor microenvironment play important roles in cancer progression. However, the mechanism of promotion of cancer metastasis by inflammation in gastric cancer (GC) is poorly understood. Methods: The roles of NEK9 were validated via loss-of-function and gain-of-function experiments in vitro and in an animal model of metastasis. Cytoskeletal reorganization-associated molecules were detected by GST pull-down. The regulation of ARHGEF2 by NEK9 was investigated by phosphoproteomics analysis, immunoprecipitation (IP) and in vitro kinase assay. The transcriptional regulation of miR-520f-3p was studied using luciferase reporter and chromatin immunoprecipitation (ChIP). The expression of these proteins in GC tissues was examined by immunohistochemistry. Results: NEK9 directly regulates cell motility and RhoA activation in GC. The phosphorylation of ARHGEF2 by NEK9 is the key step of this process. NEK9 is a direct target of miR-520f-3p, which is transcriptionally suppressed by IL-6-mediated activation of STAT3. A decrease in miR-520f-3p leads to the amplification of IL-6/STAT3 by targeting GP130. A simultaneous elevation of the levels of NEK9, GP130 and p-STAT3 was confirmed in the lymph nodes and distant metastases. An increase in NEK9, GP130 and STAT3 is associated with reduced overall survival of GC patients. Conclusion: This study demonstrates that activation of STAT3 by IL-6 transcriptionally suppresses miR-520f-3p and diminishes the inhibitory effects of miR-520f-3p on NEK9 and GP130. An increase in GP130 enhances this signaling, and NEK9 directly influences cell motility and RhoA activation by targeting the phosphorylation of ARHGEF2. Targeting the IL-6-STAT3-NEK9 pathway may be a new strategy for GC treatment.
    Keywords:  Gastric cancer; Inflammation; Metastasis; NEK9; Phosphorylation