bims-bicyki 2022-03-20 papers

bims-bicyki

Biomed News

on Bicaudal-C1 and interactors in cystic kidney disease

Issue of 2022–03–20
six papers selected by
Céline Gagnieux, École Polytechnique Fédérale de Lausanne

Mayo imaging classification is a good predictor of rapid progress among Korean patients with autosomal dominant polycystic kidney disease: results from the KNOW-CKD study.
Imaging the cAMP Signaling Microdomain of the Primary Cilium Using Targeted FRET-Based Biosensors.
Pinostrobin inhibits renal CFTR-mediated Cl- secretion and retards cyst growth in cell-derived cyst and polycystic kidney disease rats.
Primary cilia on muscle stem cells are critical to maintain regenerative capacity and are lost during aging.
ENKD1 promotes CP110 removal through competing with CEP97 to initiate ciliogenesis.
Vascular smooth muscle ROCK1 contributes to hypoxia-induced pulmonary hypertension development in mice.

Kidney Res Clin Pract. 2022 Mar 03.

Mayo imaging classification is a good predictor of rapid progress among Korean patients with autosomal dominant polycystic kidney disease: results from the KNOW-CKD study.

Hayne Cho Park, Yeji Hong, Jeong-Heum Yeon, Hyunjin Ryu, Yong-Chul Kim, Joongyub Lee, Yeong Hoon Kim, Dong-Wan Chae, WooKyung Chung, Curie Ahn, Kook-Hwan Oh, Yun Kyu Oh.

   Background: Mayo imaging classification (MIC) is a useful biomarker to predict disease progression in autosomal dominant polycystic kidney disease (ADPKD). This study was performed to validate MIC in the prediction of renal outcome in a prospective Korean ADPKD cohort and evaluate clinical parameters associated with rapid disease progression.
Methods: A total of 178 ADPKD patients were enrolled and prospectively observed for an average duration of 6.2 ± 1.9 years. Rapid progressor was defined as MIC 1C through 1E while slow progressor was defined as 1A through 1B. Renal composite outcome (doubling of serum creatinine, 50% decline of estimated glomerular filtration rate [eGFR], or initiation of renal replacement therapy) as well as the annual percent change of height-adjusted total kidney volume (mHTKV-α), and eGFR decline (mGFR-α) were compared between groups.
Results: A total of 110 patients (61.8%) were classified as rapid progressors. These patients were younger and showed a higher proportion of male patients. Rapid progressor was an independent predictor for renal outcome (hazard ratio, 4.09; 95% confidence interval, 1.23-13.54; p = 0.02). The mGFR-α was greater in rapid progressors (-3.58 mL/min per year in 1C, -3.7 in 1D, and -4.52 in 1E) compared with that in slow progressors (-1.54 in 1A and -2.06 in 1B). The mHTKV-α was faster in rapid progressors (5.3% per year in 1C, 9.4% in 1D, and 11.7% in 1E) compared with that in slow progressors (1.2% in 1A and 3.8% in 1B).
Conclusion: MIC is a good predictive tool to define rapid progressors in Korean ADPKD patients.

Keywords:  Autosomal dominant polycystic kidney; Computer-assisted image interpretation; Glomerular filtration rate; Prognosis; Renal insufficiency

DOI:  https://doi.org/10.23876/j.krcp.21.261
Methods Mol Biol. 2022 ;2483 77-92

Imaging the cAMP Signaling Microdomain of the Primary Cilium Using Targeted FRET-Based Biosensors.

Danielle T Arena, Aldebaran M Hofer.

  Optical approaches have revolutionized our view of second messenger signaling in organelles, allowing precise time-resolved assessment of soluble signaling molecules in situ. Among the most challenging of subcellular signaling microdomains to assay is the primary cilium. A petite but visually arresting organelle, the primary cilium extends from the cell surface of most non-dividing cells. Recently, the concept of the primary cilium as an independent cAMP signaling organelle has attracted substantial interest. The cilium sequesters a very specific subset of ciliary cAMP-linked GPCRs in its membrane (e.g., 5-HT6, D1R, MCR4, FFAR4, TGR5), as well as other key components of the cAMP signaling machinery that include adenylyl cyclases, GNAS, phosphodiesterases, PKA holoenzyme, and biologically important PKA targets. Here we provide a practical guide to assessing ciliary cAMP signals in live cells using targeted genetically encoded FRET biosensors. Key experimental difficulties include gathering sufficient signal from such a small, photon-limited volume, and the susceptibility of cilia to movement artifacts. Other challenges are associated with the fidelity of sensor targeting and the difficulties in distinguishing between cAMP signals produced exclusively within the cilium vs. those that emanate from the cell body. Here we describe ratio imaging approaches used in our lab for time-resolved visualization of ciliary cAMP in cultured renal cells. These methods can be readily adapted to other cell types and microscopy platforms according to the needs of the user.

Keywords:  FRET biosensors; Fluorescent proteins; Live-cell ratio imaging; PKA; Primary cilia; cAMP signaling microdomains

DOI:  https://doi.org/10.1007/978-1-0716-2245-2_5
J Pharmacol Sci. 2022 Apr;pii: S1347-8613(22)00016-0. [Epub ahead of print]148(4): 369-376

Pinostrobin inhibits renal CFTR-mediated Cl- secretion and retards cyst growth in cell-derived cyst and polycystic kidney disease rats.

Kanlayanee Tonum, Napason Chabang, Somsak Fongsupa, Suphat Chantawarin, Chutima Jiarpinitnun, Patoomrattana Tuchinda, Sunhapas Soodvilai.

  Cystic fibrosis transmembrane conductance regulator (CFTR) plays crucial role in renal cyst expansion via increase in fluid accumulation. Inhibition of CFTR has been proposed to retard cyst development and enlargement in polycystic kidney disease (PKD). Pinostrobin, a bioactive natural flavonoid, possesses several pharmacological effects. The present study investigated pharmacological effects of pinostrobin on CFTR-mediated Cl- secretion and renal cyst expansion in in vitro and in vivo models. Pinostrobin (10 and 50 μM) reduced number of MDCK cell-derived cyst colonies and inhibited cyst expansion via inhibition of cell proliferation and CFTR-mediated Cl- secretion. The inhibitory effect of pinostrobin was not due to the decrease in cell viability and activity of Na+-K+-ATPase. We also investigated the natural analogue pinocembrin as well as the synthetic analogue pinostrobin oxime. Both pinocembrin and pinostrobin oxime did not reduce CFTR-mediated Cl- secretion. In PKD rats, oral administration of pinostrobin (40 mg/kg/day) exhibited a decreasing in cystic area compared to vehicle-treated rats. Pinostrobin treatment inhibited renal expression of CFTR protein in PKD rats. Our findings highlighted the potential therapeutic application of pinostrobin in PKD.

Keywords:  CFTR; Flavonoids; Fluid secretion; PCK rats; Polycystic kidney disease

DOI:  https://doi.org/10.1016/j.jphs.2022.02.003
Nat Commun. 2022 Mar 17. 13(1): 1439

Primary cilia on muscle stem cells are critical to maintain regenerative capacity and are lost during aging.

Adelaida R Palla, Keren I Hilgendorf, Ann V Yang, Jaclyn P Kerr, Aaron C Hinken, Janos Demeter, Peggy Kraft, Nancie A Mooney, Nora Yucel, David M Burns, Yu Xin Wang, Peter K Jackson, Helen M Blau.

During aging, the regenerative capacity of muscle stem cells (MuSCs) decreases, diminishing the ability of muscle to repair following injury. We found that the ability of MuSCs to regenerate is regulated by the primary cilium, a cellular protrusion that serves as a sensitive sensory organelle. Abolishing MuSC cilia inhibited MuSC proliferation in vitro and severely impaired injury-induced muscle regeneration in vivo. In aged muscle, a cell intrinsic defect in MuSC ciliation was associated with the decrease in regenerative capacity. Exogenous activation of Hedgehog signaling, known to be localized in the primary cilium, promoted MuSC expansion, both in vitro and in vivo. Delivery of the small molecule Smoothened agonist (SAG1.3) to muscles of aged mice restored regenerative capacity leading to increased strength post-injury. These findings provide fresh insights into the signaling dysfunction in aged MuSCs and identify the ciliary Hedgehog signaling pathway as a potential therapeutic target to counter the loss of muscle regenerative capacity which accompanies aging.

DOI: https://doi.org/10.1038/s41467-022-29150-6
EMBO Rep. 2022 Mar 18. e54090

ENKD1 promotes CP110 removal through competing with CEP97 to initiate ciliogenesis.

Ting Song, Yunfan Yang, Peng Zhou, Jie Ran, Liang Zhang, Xiaofan Wu, Wei Xie, Tao Zhong, Hongbin Liu, Min Liu, Dengwen Li, Huijie Zhao, Jun Zhou.

  Despite the importance of cilia in cell signaling and motility, the molecular mechanisms regulating cilium formation remain incompletely understood. Herein, we characterize enkurin domain-containing protein 1 (ENKD1) as a novel centrosomal protein that mediates the removal of centriolar coiled-coil protein 110 (CP110) from the mother centriole to promote ciliogenesis. We show that Enkd1 knockout mice possess ciliogenesis defects in multiple organs. Super-resolution microscopy reveals that ENKD1 is a stable component of the centrosome throughout the ciliogenesis process. Simultaneous knockdown of ENKD1 and CP110 significantly reverses the ciliogenesis defects induced by ENKD1 depletion. Protein interaction analysis shows that ENKD1 competes with centrosomal protein 97 (CEP97) in binding to CP110. Depletion of ENKD1 enhances the CP110-CEP97 interaction and detains CP110 at the mother centriole. These findings thus identify ENKD1 as a centrosomal protein and uncover a novel mechanism controlling CP110 removal from the mother centriole for the initiation of ciliogenesis.

Keywords:  CP110; ENKD1; centrosome; ciliogenesis; cilium

DOI:  https://doi.org/10.15252/embr.202154090
Biochem Biophys Res Commun. 2022 Mar 09. pii: S0006-291X(22)00253-4. [Epub ahead of print]604 137-143

Vascular smooth muscle ROCK1 contributes to hypoxia-induced pulmonary hypertension development in mice.

Krishna C Penumatsa, Adit A Singhal, Rod R Warburton, Michael D Bear, Chinmayee D Bhedi, Sabina Nasirova, Jamie L Wilson, Guanming Qi, Ioana R Preston, Nicholas S Hill, Barry L Fanburg, Young-Bum Kim, Deniz Toksoz.

Rho kinase (ROCK) is implicated in the development of pulmonary arterial hypertension (PAH) in which abnormal pulmonary vascular smooth muscle (VSM) contractility and remodeling lead to right heart failure. Pharmacologic ROCK inhibitors block experimental pulmonary hypertension (PH) development in rodents but can have off-target effects and do not distinguish between the two ROCK forms, ROCK1 and ROCK2, encoded by separate genes. An earlier study using gene knock out (KO) in mice indicated that VSM ROCK2 is required for experimental PH development, but the role of ROCK1 is not well understood. Here we investigated the in vivo role of ROCK1 in PH development by generating a VSM-targeted homozygous ROCK1 gene KO mouse strain. Adult control mice exposed to Sugen5416 (Su)/hypoxia treatment to induce PH had significantly increased right ventricular systolic pressures (RVSP) and RV hypertrophy versus normoxic controls. In contrast, Su/hypoxia-exposed VSM ROCK1 KO mice did not exhibit significant RVSP elevation, and RV hypertrophy was blunted. Su/hypoxia-induced pulmonary small vessel muscularization was similarly elevated in both control and VSM ROCK1 KO animals. siRNA-mediated ROCK1 knock-down (KD) in human PAH pulmonary arterial SM cells (PASMC) did not affect cell growth. However, ROCK1 KD led to reduced AKT and MYPT1 signaling in serotonin-treated PAH PASMC. The findings suggest that like VSM ROCK2, VSM ROCK1 actively contributes to PH development, but in distinction acts via nonproliferative pathways to promote hypoxemia, and thus may be a distinct therapeutic target in PH.

DOI: https://doi.org/10.1016/j.bbrc.2022.02.064