bims-bicyki Biomed News
on Bicaudal-C1 and interactors in cystic kidney disease
Issue of 2021‒08‒22
sixteen papers selected by
Céline Gagnieux
École Polytechnique Fédérale de Lausanne (EPFL)

  1. J Cereb Blood Flow Metab. 2021 Aug 20. 271678X211037869
      Cilia dysfunction in autosomal-dominant polycystic kidney disease (ADPKD) may impair the integrity of glymphatic system and be implicated in the progression of cerebral small vessel disease (SVD), although the link between the two diseases has not been investigated. We evaluated the association of ADPKD pathology with SVD pattern and severity. Overall, 304 individuals in an ADPKD (chronic kidney disease stage ≤4 and age ≥50 years) cohort and their age, sex, and estimated glomerular filtration rate (eGFR)-matched controls were retrospectively included. ADPKD severity was classified into 1 A-B, 1 C, and 1 D-E, according to age and height-adjusted total kidney volume. SVD parameters included white-matter hyperintensity (WMH) severity scale, enlarged perivascular space (ePVS) score, and degree of lacunes or cerebral microbleeds (CMBs). After adjustments for age, sex, eGFR, and cerebrovascular risk factor parameters, ADPKD was associated with higher ePVS scores (P < 0.001), but not with the WMH severity or degree of lacunes or CMBs. In the ADPKD subgroup, higher ADPKD severity class was associated with higher ePVS scores (P < 0.001), WMH severity (P = 0.003), and degree of lacunes (P = 0.002). ADPKD associated cilia dysfunction may induce chronic cerebral glymphatic system dysfunction, which may contribute to the specific progression of ePVS compared with other SVD markers.
    Keywords:  Autosomal dominant polycystic kidney disease; cilia dysfunction; enlarged perivascular space; glymphatic system; small vessel disease
  2. Kidney Med. 2021 Jul-Aug;3(4):3(4): 536-545.e1
      Rationale & Objective: Pain is a frequent complication of autosomal dominant polycystic kidney disease (ADPKD) and includes back and abdominal pain. We hypothesized that in adults with early- and late-stage ADPKD, overweight and obesity are independently associated with greater self-reported back, abdominal, and radicular pain at baseline and that weight loss would be associated with decreased pain over a follow-up period.Study Design: Post hoc analysis of pooled data from 2 randomized trials.
    Setting & Participants: Participants in the HALT-PKD study A or B. 867 individuals were included in a cross-sectional analysis. 4,248 observations from 871 participants were included in a longitudinal analysis.
    Predictor: Overweight and obesity (cross-sectional); annual change in weight as a time-varying predictor (longitudinal).
    Outcome: Pain (Likert-scale responses; cross-sectional); annual change in pain (binary outcome of worsening pain or not worsening; longitudinal).
    Analytical Approach: Multivariable ordinal logistic regression (cross-sectional); generalized estimating equation analysis (longitudinal).
    Results: Participants were aged 42±10 years and baseline estimated glomerular filtration rate was 71±26 mL/min/1.73 m2. Back, abdominal, and radicular pain were reported more frequently in individuals with increasing body mass index category (all P < 0.05 for trend). After multivariable adjustment, obesity was associated with increased odds of greater back and radicular pain, but not abdominal pain. Associations remained similar after further adjustment for baseline height-adjusted kidney and liver volume (study A only, n = 457); back pain: OR, 1.88 (95% CI, 1.15-3.08); and radicular pain: OR, 2.92 (95% CI, 1.45-5.91). Longitudinally (median follow-up, 5 years), weight loss (annual decrease in weight ≥ 4%) was associated with decreased adjusted odds of worsening back pain (OR, 0.87 [95% CI, 0.76-0.99]) compared with the reference group (stable weight).
    Limitations: Post hoc, associative analysis.
    Conclusions: In early- and late-stage ADPKD, obesity was associated with greater back and radicular pain independent of total kidney/liver volume. Mild weight loss was associated with favorable effects on back pain.
    Keywords:  Body mass index; obesity; pain; polycystic kidney disease; weight loss
  3. Am J Kidney Dis. 2021 Aug 12. pii: S0272-6386(21)00790-3. [Epub ahead of print]
      RATIONALE & OBJECTIVE: Autosomal dominant polycystic kidney disease (ADPKD) is a common inherited disorder that leads to kidney failure and has few treatment options. Metformin is well tolerated and safe in other patient populations. The primary objective of this clinical trial was to determine the safety and tolerability of metformin in patients with ADPKD and without diabetes mellitus.STUDY DESIGN: Prospective, randomized, controlled, double-blind clinical trial.
    SETTING & PARTICIPANTS: N=51 adults 30-60 years of age with ADPKD, without diabetes, and an estimated glomerular filtration rate (eGFR) 50-80 mL/min/1.73 m2.
    INTERVENTION: Metformin (maximum dose 2,000 mg/day) or placebo for 12 months.
    OUTCOMES: Co-primary endpoints were the percentage of participants in each group prescribed at the end of the 12-month period: (a) the full randomized dose, and (b) at least 50% of the randomized dose. Secondary and exploratory outcomes were the effect of metformin compared to placebo on (a) percent change in TKV referenced to height (htTKV in mL/m) and (b) change in eGFR over a 12-month period.
    RESULTS: Mean age was 48 ± 8 years and eGFR was 70 ± 14 mL/min/1.73m2. The metformin group had no cases of lactic acidosis and there was one episode of mild hypoglycemia in each group. Participants in the metformin group reported more adverse symptoms, mostly related to gastrointestinal symptoms. 11 of 22 (50%) of metformin-treated participants completed the treatment phase on the full dose compared to 23 of 23 (100%) in the placebo group. 82% of participants on metformin tolerated at least 50% of the dose, compared to 100% in the placebo group. In exploratory analyses, changes in height-adjusted total kidney volume or eGFR were not significantly different between groups.
    LIMITATIONS: Short study duration.
    CONCLUSIONS: 50% or more of the maximal metformin dose was safe and well tolerated over 12 months in patients with ADPKD. Safety of other preparations of metformin as well as its efficacy should be tested in future clinical trials.
    Keywords:  AMPK activator; Key words: Autosomal dominant polycystic kidney disease; estimated glomerular filtration rate; metformin; total kidney volume
  4. Sci Rep. 2021 Aug 16. 11(1): 16532
      Recent advances in induced pluripotent stem cells (iPSCs), genome editing technologies and 3D organoid model systems highlight opportunities to develop new in vitro human disease models to serve drug discovery programs. An ideal disease model would accurately recapitulate the relevant disease phenotype and provide a scalable platform for drug and genetic screening studies. Kidney organoids offer a high cellular complexity that may provide greater insights than conventional single-cell type cell culture models. However, genetic manipulation of the kidney organoids requires prior generation of genetically modified clonal lines, which is a time and labor consuming procedure. Here, we present a methodology for direct differentiation of the CRISPR-targeted cell pools, using a doxycycline-inducible Cas9 expressing hiPSC line for high efficiency editing to eliminate the laborious clonal line generation steps. We demonstrate the versatile use of genetically engineered kidney organoids by targeting the autosomal dominant polycystic kidney disease (ADPKD) genes: PKD1 and PKD2. Direct differentiation of the respective knockout pool populations into kidney organoids resulted in the formation of cyst-like structures in the tubular compartment. Our findings demonstrated that we can achieve > 80% editing efficiency in the iPSC pool population which resulted in a reliable 3D organoid model of ADPKD. The described methodology may provide a platform for rapid target validation in the context of disease modeling.
  5. JMA J. 2021 Jul 15. 4(3): 207-215
      Autophagy is a major intracellular degradation system and plays important roles in various physiological processes such as metabolic adaptation and intracellular homeostasis. It degrades intracellular components both randomly and selectively. Autophagic activity is tightly regulated primarily by nutrient availability, but also by other extracellular and intracellular signals. Growing evidence suggests that there are multiple links between autophagy and the primary cilium. The primary cilium is an organelle present on the cell surface and is important for keeping cellular integrity by transducing extracellular stimuli inside the cell. Recent studies have revealed that autophagy selectively degrades the ciliogenesis inhibitory proteins OFD1 and MYH9, promoting ciliogenesis. Conversely, autophagy also inhibits ciliogenesis under growth conditions. The primary cilium can also regulate autophagic activity. These findings suggest that the relationship between autophagy and the primary cilia is bidirectional, and that both are important for maintaining the normal function of various organs.
    Keywords:  autophagy; ciliogenesis; ciliopathy
  6. Biochem Biophys Res Commun. 2021 Aug 12. pii: S0006-291X(21)01207-9. [Epub ahead of print]573 145-150
      Osteocytes are accepted as the primary mechanosensing cell in bone, but how they translate mechanical signals into biochemical signals remains unclear. Adenylyl cyclases (AC) are enzymes that catalyze the production of second messenger cyclic adenosine monophosphate (cAMP). Osteocytes display a biphasic, cAMP response to fluid shear with an initial decrease in cAMP concentrations and then an increased concentration after sustained mechanical stimulation. To date, AC6, a calcium-inhibited AC, is the primary isoform studied in bone. Since osteocytes are calcium-responsive mechanosensors, we asked if a calcium-stimulated isoform contributes to mechanotransduction. Using a transcriptomic dataset of MLO-Y4 osteocyte-like cells from the NIH Gene Expression Omnibus, we identified AC3 as the only calcium-stimulated isoform expressed. We show that inhibiting AC3 in MLO-Y4 cells results in decreased cAMP-signaling with fluid shear and increased osteogenic response to fluid flow (measured as Ptgs2 expression) of longer durations, but not shorter. AC3 likely contributes to osteocyte mechanotransduction through a signaling axis involving the primary cilium and GSK3β. We demonstrate that AC3 localizes to the primary cilium, as well as throughout the cytosol and that fluid-flow regulation of primary cilia length is altered with an AC3 knockdown. Regulation of GSK3β is downstream of the primary cilium and cAMP signaling, and with western blots we found that GSK3β inhibition by phosphorylation is increased after fluid shear in AC3 knockdown groups. Our data show that AC3 contributes to osteocyte mechanotransduction and warrants further investigation to pave the way to identifying new therapeutic targets to treat bone disease like osteoporosis.
    Keywords:  Adenylyl cyclase 3; Gsk3beta; Mechanotransduction; Osteocyte; Primary cilium; cAMP
  7. Biol Psychiatry. 2021 Jun 17. pii: S0006-3223(21)01395-0. [Epub ahead of print]
      BACKGROUND: Morphine is used extensively in the clinical setting owing to its beneficial effects, such as pain relief; its therapeutic utility is limited because the prolonged use of morphine often results in tolerance and addiction. Astrocytes in the brain are a direct target of morphine action and play an essential role in the development of morphine tolerance. Primary cilia and the cilia-mediated sonic hedgehog (SHH) signaling pathways have been shown to play a role in drug resistance and morphine tolerance, respectively. Extracellular vesicles (EVs) play important roles as cargo-carrying vesicles mediating communication among cells and tissues.METHODS: C57BL/6N mice were administered morphine for 8 days to develop tolerance, which was determined using the tail-flick and hot plate assays. EVs were separated from astrocyte-conditioned media using either size exclusion chromatography or ultracentrifugation approaches, followed by characterization of EVs using nanoparticle tracking analysis for EV size distribution and number, Western blotting for EV markers, and electron microscopy for EV morphology. Astrocytes were treated with EVs for 24 hours, followed by assessing primary cilia by fluorescent immunostaining for primary cilia markers (ARL13B and acetylated tubulin).
    RESULTS: Morphine-tolerant mice exhibited an increase in primary cilia length and percentage of ciliated astrocytes. The levels of SHH protein were upregulated in morphine-stimulated astrocyte-derived EVs. SHH on morphine-stimulated astrocyte-derived EVs activated SHH signaling in astrocytes through primary cilia. Our in vivo study demonstrated that inhibition of either EV release or primary cilia prevents morphine tolerance in mice.
    CONCLUSIONS: EV-mediated primary ciliogenesis contributes to the development of morphine tolerance.
    Keywords:  Astrocyte; Extracellular vesicle; Morphine tolerance; Primary cilia; Sonic hedgehog
  8. PLoS Genet. 2021 Aug 19. 17(8): e1009752
      The cilium, the sensing centre for the cell, displays an extensive repertoire of receptors for various cell signalling processes. The dynamic nature of ciliary signalling indicates that the ciliary entry of receptors and associated proteins must be regulated and conditional. To understand this process, we studied the ciliary localisation of the odour-receptor coreceptor (Orco), a seven-pass transmembrane protein essential for insect olfaction. Little is known about when and how Orco gets into the cilia. Here, using Drosophila melanogaster, we show that the bulk of Orco selectively enters the cilia on adult olfactory sensory neurons in two discrete, one-hour intervals after eclosion. A conditional loss of heterotrimeric kinesin-2 during this period reduces the electrophysiological response to odours and affects olfactory behaviour. We further show that Orco binds to the C-terminal tail fragments of the heterotrimeric kinesin-2 motor, which is required to transfer Orco from the ciliary base to the outer segment and maintain within an approximately four-micron stretch at the distal portion of the ciliary outer-segment. The Orco transport was not affected by the loss of critical intraflagellar transport components, IFT172/Oseg2 and IFT88/NompB, respectively, during the adult stage. These results highlight a novel developmental regulation of seven-pass transmembrane receptor transport into the cilia and indicate that ciliary signalling is both developmentally and temporally regulated.
  9. J Cell Biol. 2021 Sep 06. pii: e202107033. [Epub ahead of print]220(9):
      Centriole maturation is essential for ciliogenesis, but which proteins and how they regulate ciliary assembly is unclear. In this issue, Kumar et al. (2021. J. Cell Biol. shed light on this process by identifying a ciliopathy complex at the distal mother centriole that restrains centriole length and supports the formation of distal appendages.
  10. Int J Cardiol Heart Vasc. 2021 Oct;36 100852
      Background: Studies of insulin-like growth factor 1 (IGF-1) as a novel therapy for the treatment of cardiovascular diseases have proven promising. However, elevated IGF-1 levels have also been associated with poor patient outcomes in heart failure with reduced ejection fraction. IGF-1 therapy has additionally been shown to not be beneficial in the percutaneous coronary intervention setting. Although IGF-1 activation of the PI3K/Akt and ERK1/2 pathways have been demonstrated as cardioprotective, other cellular mechanisms have not been fully investigated.Methods: Neonatal rat cardiac myocytes (NCMs) and fibroblasts (NCFs) were isolated from 1 to 2-day old pups using enzymatic digestion. NCMs and NCFs were pre-treated with IGF binding protein 6, inhibitors for the PI3K/Akt Wortmannin, ERK1/2 U0126, Rho Associated Protein Kinase (ROCK) GSK576371, Apoptosis Signal-regulating Kinase-1 (ASK-1) G2261818A, and p38MAPK RWJ67657 pathways before stimulation with IGF-1 for 62 and 50 h, respectively. Cardiac myocyte hypertrophy and fibroblast collagen synthesis were determined by 3H-leucine and 3H-proline incorporation, respectively.
    Results: IGF-1 dose-dependently stimulated NCM hypertrophy and NCF collagen synthesis.Treatment with IGFBP6 and the kinase inhibitors, Wortmannin, U0126, GSK576371, G2261818A and RWJ67657 significantly inhibited IGF-1 stimulated NCM hypertrophy and NCF collagen synthesis.
    Conclusion: This study is the first to demonstrate that IGF-1 treatment in NCMs and NCFs activates the ROCK, ASK-1 and p38MAPK pathways. Future research may be guided by consideration of the PI3K/Akt and ERK1/2 pathways potentially increasing collagen synthesis, and the utilisation of a biased agonist to reduce activation of the ROCK, ASK-1 and p38MAPK pathways to maximise cardioprotective benefit whilst mitigating risks.
    Keywords:  Apoptosis Signal-regulating Kinase 1; Cardiac cellular remodelling; Insulin-like growth factor 1; Rho Associated Protein Kinase; p38 MAPK
  11. CNS Neurol Disord Drug Targets. 2021 Aug 19.
      BACKGROUND: Alzheimer's disease is rapidly becoming a major threat to public health, with an increasing number of individuals affected as the world's population ages. In this sense, studies have been carried out aiming at the identification of new small-molecule kinase inhibitors useful for the treatment of Alzheimer's disease.OBJECTIVE: In the present study, we investigated the compounds developed as inhibitors of different protein kinases associated with the pathogenesis of Alzheimer's disease.
    METHODS: The applied methodology was the use of the Clarivate Analytics Integrity and databases. Moreover, we highlight ROCK2 as a promising target despite being little studied for this purpose. A careful structure-activity relationship analysis of the ROCK2 inhibitors was performed to identify important structural features and fragments for the interaction with the kinase active site, aiming to rationally design novel potent and selective inhibitors.
    RESULTS: We were able to notice some structural characteristics that could serve as the basis to better guide the rational design of new ROCK2 inhibitors as well as some more in-depth characteristics regarding the topology of the active site of both isoforms of these enzymes, thereby identifying differences that could lead to planning more selective compounds.
    CONCLUSION: We hope that this work can be useful to update researchers working in this area, enabling the emergence of new ideas and a greater direction of efforts for designing new ROCK2 inhibitors to identify new therapeutic alternatives for Alzheimer's disease.
    Keywords:  Alzheimer's disease; Kinase inhibitors; Neurodegenerative diseases; ROCK2; ROCK2 inhibitor; Rho kinase 2
  12. Clin Immunol. 2021 Aug 14. pii: S1521-6616(21)00160-1. [Epub ahead of print]230 108823
      Chronic graft-versus-host disease (cGVHD) is an immune-mediated disorder characterized by chronic inflammation and fibrosis. Rho-associated coiled-coil-containing protein kinases (ROCKs) are key coordinators of tissue response to injury, regulating multiple functions, such as gene expression and cell migration, proliferation and survival. Relevant to cGVHD and autoimmunity, only the ROCK2 isoform drives a pro-inflammatory type 17 helper T (Th17) cell response. Moreover, ROCK2 inhibition shifts the Th17/regulatory T (Treg) cell balance toward Treg cells and restores immune homeostasis in animal models of autoimmunity and cGVHD. Furthermore, the selective inhibition of ROCK2 by belumosudil reduces fibrosis by downregulating both transforming growth factor-β signaling and profibrotic gene expression, thereby impeding the creation of focal adhesions. Consistent with its anti-inflammatory and antifibrotic activities, belumosudil has demonstrated efficacy in clinical studies, resulting in an overall response rate of >70% in patients with cGVHD who failed 2 to 5 prior lines of systemic therapy. In summary, selective ROCK2 inhibition has emerged as a promising novel therapeutic approach for treating cGVHD and other immunologic diseases with unique mechanisms of action, targeting both immune imbalance and detrimental fibrotic responses.
    Keywords:  Autoimmunity; Belumosudil; Chronic graft-versus-host disease; Fibrosis; Immunomodulation; ROCK2
  13. Chem Biol Interact. 2021 Aug 17. pii: S0009-2797(21)00263-5. [Epub ahead of print] 109625
      Catalpol is an iridoid glycoside compound isolated from the root of Rehmannia glutinosa, which has been reported to be a promising candidate for the treatment of diabetic diseases. The present study aimed at investigating the effects and potential mechanism of catalpol on endothelial dysfunction and inflammation in diabetic nephropathy (DN). We constructed DN mice and advanced glycation end products (AGEs)-induced mouse glomerular endothelial cells (mGECs) injury model. The results demonstrated that catalpol effectively improved renal pathology and decreased levels of urine protein, serum creatinine, and blood urea nitrogen in DN mice. Catalpol significantly reduced endothelial dysfunction and inflammatory infiltration of macrophages in DN mice and AGEs-induced mGECs. To further study the protective mechanism of catalpol, we transfected DN mice with recombinant adeno-associated virus expressing receptor of AGEs (RAGE) and intervened AGEs-induced mGECs with inhibitors. Catalpol reversed endothelial dysfunction and inflammation aggravated by RAGE overexpression in DN mice. Meanwhile, catalpol significantly inhibited the RAGE/Ras homolog gene family member A (RhoA)/Rho-associated kinase (ROCK) pathway in DN mice with RAGE overexpression. Moreover, the combination of catalpol with inhibitors of RAGE, RhoA and ROCK exerted stronger anti-endothelial dysfunction and anti-macrophage infiltration effects on AGEs-induced mGECs compared with catalpol alone. In short, this study indicated that catalpol could ameliorate endothelial dysfunction and inflammation via suppression of RAGE/RhoA/ROCK pathway, hereby delaying the progression of DN.
    Keywords:  AGEs; Catalpol; Diabetic nephropathy; Endothelial dysfunction; Inflammation; RAGE/RhoA/ROCK pathway
  14. BMC Anesthesiol. 2021 Aug 16. 21(1): 203
      BACKGROUND: Cerebral ischemia/reperfusion injury (CIRI) is a complication of surgical procedure associated with high mortality. The protective effect of dexmedetomidine (DEX) on CIRI has been explored in previous works, yet the underlying molecular mechanism remains unclear. Our study explored the protective effect of DEX and its regulatory mechanism on CIRI.METHODS: A CIRI rat model was established using middle cerebral artery occlusion (MCAO). Neurological deficit scores for rats received MCAO modeling or DEX treatment were measured. Cerebral infarction area of rats was detected by TTC staining, while damage of neurons in hippocampal regions of rats was determined by hematoxylin-eosin (HE) staining. Apoptosis rate of neurons in hippocampal regions was examined by TUNEL staining. The dual-luciferase assay was performed to detect the binding of microRNA-214 (miR-214) to Rho-associated kinase 1 (ROCK1).
    RESULTS: DEX treatment significantly reduced infarction area of MCAO rats and elevated miR-214 expression. Injection of miR-214 inhibitor attenuated the effect of DEX in MCAO rats by increasing the area of cerebral infarction in rats and apoptosis rate of hippocampal neurons. ROCK1 was targeted and negatively regulated by miR-214. The overexpression of ROCK1 led to activation of NF-κB to aggravate CIRI.
    CONCLUSION: Therapeutic effects of DEX on CIRI was elicited by overexpressing miR-214 and impairing ROCK1 expression and NF-κB activation. Our finding might provide novel insights into the molecular mechanism of DEX in rats with CIRI.
    Keywords:  Cerebral ischemia/reperfusion injury; Dexmedetomidine; NF-κB; Rho-associated kinase 1; microRNA-214
  15. Biomed Res Int. 2021 ;2021 5561221
      Brucea javanica oil (BJO) is beneficial for the treatment of ulcerative colitis (UC), and that quassinoids in particular brusatol are bioactive components. However, it is still uncertain whether or not other components in BJO, such as oleic acid and fatty acids, have an anti-UC effect. The present study is aimed at comparing the anti-UC effects between brusatol-enriched BJO (BE-BJO) and brusatol-free BJO (BF-BJO) and at exploring the effects and mechanisms of BE-BJO on colon inflammation and intestinal epithelial barrier function. Balb/C mice received 3% (wt/vol) DSS for one week to establish the UC model. Different doses of BE-BJO, BF-BJO, or BJO were treated. The result illustrated that BE-BJO alleviated DSS-induced loss of body weight, an increase of disease activity index (DAI), and a shortening of colon, whereas BF-BJO did not have these protective effects. BE-BJO treatment improved the morphology of colon tissue, inhibited the production and release of TNF-α, IFN-γ, IL-6, and IL-1β in the colon tissue, and reversed the decreased expressions of ZO-1, occludin, claudin-1, and E-cadherin induced by DSS but augmented claudin-2 expression. Mechanistically, BE-BJO repressed phosphorylation of NF-κB subunit p65, suppressed RhoA activation, downregulated ROCK, and prevented phosphorylation of myosin light chain (MLC) in DSS-treated mice, indicating that the protective effect of BE-BJO is attributed to suppression of NF-κB and RhoA/ROCK signaling pathways. These findings confirm that brusatol is an active component from BJO in the treatment of UC.