bims-bicyki Biomed News
on Bicaudal-C1 and interactors in cystic kidney disease
Issue of 2021‒04‒25
twenty-four papers selected by
Céline Gagnieux
École Polytechnique Fédérale de Lausanne (EPFL)

  1. JBMR Plus. 2021 Apr;5(4): e10464
      Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited cause of chronic kidney disease (CKD) and leads to a specific type of bone disease. The primary cilium is a major cellular organelle implicated in the pathophysiology of ADPKD caused by mutations in polycystin-1 (PKD1) and polycystin-2 (PKD2). In this study, for the first time, cilia were characterized in primary preosteoblasts isolated from patients with ADPKD. All patients with ADPKD had low bone turnover and primary osteoblasts were also obtained from patients with non-ADPKD CKD with low bone turnover. Image-based immunofluorescence assays analyzed cilia using standard markers, pericentrin, and acetylated-α-tubulin, where cilia induction and elongation were chosen as relevant endpoints for these initial investigations. Osteoblastic activity was examined by measuring alkaline phosphatase levels and mineralized matrix deposition rates. It was found that primary cilia can be visualized in patient-derived osteoblasts and respond to elongation treatments. Compared with control cells, ADPKD osteoblasts displayed abnormal cilia elongation that was significantly more responsive in cells with PKD2 nontruncating mutations and PKD1 mutations. In contrast, non-ADPKD CKD osteoblasts were unresponsive and had shorter cilia. Finally, ADPKD osteoblasts showed increased rates of mineralized matrix deposition compared with non-ADPKD CKD. This work represents the first study of cilia in primary human-derived osteoblasts from patients with CKD and patients with ADPKD who have normal kidney function, offering new insights as bone disease phenotypes are not well recapitulated in animal models. These data support a model whereby altered cilia occurs in PKD-mutated osteoblasts, and that ADPKD-related defects in bone cell activity and mineralization are distinct from adynamic bone disease from patients with non-ADPKD CKD. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.
  2. Int J Nephrol Renovasc Dis. 2021 ;14 105-115
      Background: Autosomal dominant polycystic kidney disease (ADPKD) is a rare inherited kidney disorder with considerable symptom burden and negative effects even in early-stage disease. Patients' reporting of ADPKD symptom burden may differ from physicians' impressions. In this quantitative, cross-section survey study, we evaluated patient and physician assessments of symptom burden at early- and late-stage ADPKD.Methods: In the United States, 300 patients with ADPKD and 155 physicians treating patients with ADPKD completed online surveys administered by Kantar. Disease stage was categorized as early (chronic kidney disease [CKD] stages 1-3) or late (stages 4-5). Patients completed the Work Productivity and Activity Impairment Questionnaire and reported current disease symptoms. Patients and physicians assessed impacts of ADPKD on daily life and burden of specific symptoms. Statistical analyses compared patient versus physician responses stratified by early- versus late-stage ADPKD.
    Results: We found that impairment in work productivity was statistically greater in late- versus early-stage CKD. Compared with physicians' impressions, patients were more likely at early stages and less likely at later stages to report a moderate/strong impact of ADPKD on daily life. Among patients, 74% with early- and 88% with late-stage disease reported that ADPKD caused them to modify their daily lives. In early-stage disease, patients reported a statistically greater burden from feeling exhausted and less burden from dull kidney pain, cardiovascular problems, high blood pressure, and liver cysts than physicians assumed. At later stages, patients reported feeling exhausted and skeletal/joint pain as more burdensome, and frequent urination, high blood pressure, liver cysts, and hematuria as less burdensome, compared with physicians' impressions.
    Conclusion: The results of this survey study demonstrate a disconnect between patients' experiences and physicians' awareness of the burden of ADPKD and highlight the need for more patient/physician discussion of symptoms and disease management.
    Keywords:  ADPKD; autosomal dominant polycystic kidney disease; patient reports; physician views; survey; symptom burden
  3. J Biol Chem. 2021 Apr 16. pii: S0021-9258(21)00469-5. [Epub ahead of print] 100680
      Primary cilia are hubs for several signaling pathways, and disruption in cilia function and formation leads to a range of diseases collectively known as ciliopathies. Both ciliogenesis and cilia maintenance depend on vesicle trafficking along a network of microtubules and actin filaments toward the basal body. The DIAPH (Diaphanous-related) family of formins promote both actin polymerization and microtubule (MT) stability. Recently, we showed that the formin DIAPH1 is involved in ciliogenesis. However, the role of other DIAPH family members in ciliogenesis had not been investigated. Here we show that depletion of either DIAPH2 or DIAPH3 also disrupted ciliogenesis and cilia length. DIAPH3 depletion also reduced trafficking within cilia. To specifically examine the role of DIAPH3 at the base, we used fused full length DIAPH3 to centrin, which targeted DIAPH3 to the basal body, causing increased trafficking to the ciliary base, an increase in cilia length and formation of bulbs at the tips of cilia. Additionally, we confirmed that the microtubule-stabilizing properties of DIAPH3 are important for its cilia length functions and trafficking. These results indicate the importance of DIAPH proteins in regulating cilia maintenance. Moreover, defects in ciliogenesis caused by DIAPH depletion could only be rescued by expression of the specific family member depleted, indicating non-redundant roles for these proteins.
    Keywords:  DIAPH2; DIAPH3; cilia; cilia maintenance; ciliogenesis
  4. JCI Insight. 2021 Apr 22. pii: 146041. [Epub ahead of print]
      Flow-activated Na+ and HCO3- transport in kidney proximal tubules (PTs) underlies relatively constant fractional reabsorption during changes in glomerular filtration rate (GFR), or glomerulotubular balance (GTB). In view of hypothesized connections of epithelial cilia to flow-sensing, we examined flow-activated transport in three polycystic kidney disease-related mouse models based on inducible conditional knockout (KO) of Pkd1, Pkd2, and Kif3a. PTs. were harvested from mice after gene inactivation but prior to cyst formation, and flow-mediated PTs transport were measured. We confirm that higher flow increases both Na+ and HCO3- absorption in control and observe that this flow effect is preserved in PTs of Pkd1-/- and Kif3a-/-mice. However, flow-activation is absent in Pkd2+/- and Pkd2-/- proximal tubules. In heterozygous (Pkd2+/-) mice, a dopamine receptor (DA1) antagonist (SCH23390) restored transport flow sensitivity. When given chronically, this same antagonist reduced renal cyst formation in Pkd2-/- as evidenced by reduced kidney weight, BUN and the cystic index, when compared to untreated mice. In contrast, SCH23390 did not prevent cyst formation in Pkd1-/- mice. These results indicate that Pkd2 is necessary for normal GTB, and that restoration of flow-activated transport by DA1 antagonist can slow renal cyst formation in Pkd2-/- mice.
    Keywords:  Drug therapy; Mouse models; Nephrology; Transport
  5. J Am Soc Nephrol. 2021 Apr 22. pii: ASN.2020101512. [Epub ahead of print]
      BACKGROUND: The V2 receptor antagonist tolvaptan is prescribed to patients with autosomal dominant polycystic kidney disease to slow disease progression. Tolvaptan may alter BP via various acute and chronic effects.METHODS: To investigate the magnitude and time course of the effect of tolvaptan use on BP, we conducted a post hoc study of the TEMPO 3:4 trial, which included 1445 patients with autosomal dominant polycystic kidney disease randomized 2:1 to tolvaptan or placebo for 3 years. We evaluated systolic and diastolic BP, mean arterial pressure, hypertension status, and use and dosing of antihypertensive drugs over the course of the trial.
    RESULTS: At baseline, BP did not differ between study arms. After 3 weeks of tolvaptan use, mean body weight had decreased from 79.7 to 78.8 kg, and mean plasma sodium increased from 140.4 to 142.6 mmol/L (both P<0.001), suggesting a decrease in circulating volume. We observed none of these changes in the placebo arm. Nonetheless, BP remained similar in the study arms. After 3 years of treatment, however, mean systolic BP was significantly lower in participants receiving tolvaptan versus placebo (126 versus 129 mm Hg, respectively; P=0.002), as was mean diastolic BP (81.2 versus 82.6 mm Hg, respectively; P=0.01). These differences leveled off at follow-up 3 weeks after discontinuation of the study medication. Use of antihypertensive drugs remained similar in both study arms during the entire study.
    CONCLUSIONS: Long-term treatment with tolvaptan gradually lowered BP compared with placebo, which may be attributed to a beneficial effect on disease progression, a continued natriuretic effect, or both.
    Keywords:  ADPKD; V2 receptor antagonist; blood pressure; vasopressin
  6. PLoS One. 2021 ;16(4): e0248400
      Augmentation of endogenous nitric oxide (NO) synthesis, either by the classical L-arginine-NO synthase pathway, or the recently discovered entero-salivary nitrate-nitrite-NO system, may slow the progression of autosomal dominant polycystic kidney disease (ADPKD). To test this hypothesis, the expression of NO in human ADPKD cell lines (WT 9-7, WT 9-12), and the effect of L-arginine on an in vitro model of three-dimensional cyst growth using MDCK cells, was examined. In addition, groups of homozygous Pkd1RC/RC mice (a hypomorphic genetic ortholog of ADPKD) received either low, moderate or high dose sodium nitrate (0.1, 1 or 10 mmol/kg/day), or sodium chloride (vehicle; 10 mmol/kg/day), supplemented drinking water from postnatal month 1 to 9 (n = 12 per group). In vitro, intracellular NO, as assessed by DAF-2/DA fluorescence, was reduced by >70% in human ADPKD cell lines, and L-arginine and the NO donor, sodium nitroprusside, both attenuated in vitro cyst growth by up to 18%. In contrast, in Pkd1RC/RC mice, sodium nitrate supplementation increased serum nitrate/nitrite levels by ~25-fold in the high dose group (P<0.001), but kidney enlargement and percentage cyst area was not altered, regardless of dose. In conclusion, L-arginine has mild direct efficacy on reducing renal cyst growth in vitro, whereas long-term sodium nitrate supplementation was ineffective in vivo. These data suggest that the bioconversion of dietary nitrate to NO by the entero-salivary pathway may not be sufficient to influence the progression of renal cyst growth in ADPKD.
  7. Cureus. 2021 Mar 15. 13(3): e13905
      We report a case of exceptionally large kidneys in autosomal dominant polycystic kidney disease (ADPKD) in India. A 43-year-old male with a family history of ADPKD presented with abdominal pain, intermittent fever, and a sense of bilateral fullness in both flanks. On examination, he had bilaterally enlarged kidneys extending towards iliac fossae. The serum metabolic panel revealed elevated serum creatinine and blood urea nitrogen. Ultrasound abdomen and pelvis showed enlarged kidneys with parenchyma replaced by multiple varying-sized cysts and few cysts in both the kidneys leading to hemorrhagic transformation. CT abdomen showed bulky bilateral kidneys with multiple non-communicating cysts, with few cysts showing the hemorrhagic and calcific transformation. The right kidney measured 30.3 x 15 cm, weighing 9 lb, was resected. The left kidney measured 37.0 x 14.0 cm and was resected three months later. The specimen weighed 19.8 lb. Histopathological examination showed a gross specimen with a bossellated surface composed of sub-capsular multiple cysts of varying sizes. Both the enlarged kidneys were resected due to cyst hemorrhage and infection. The patient is currently on hemodialysis until he receives a renal graft.
    Keywords:  adpdk; autosomal dominant; nephrectomy; polycystic kidney
  8. JSLS. 2021 Jan-Mar;25(1):pii: e2020.00107. [Epub ahead of print]25(1):
      Background and Objectives: Laparoscopic nephrectomy is now considered a feasible surgical approach, even for large kidneys. In the case of massive kidneys, laparoscopy can be problematic, so that some authors suggest an open approach. However, previous studies have shown that hand-assisted laparoscopic nephrectomy (HALN) may represent a useful compromise.We describe our hand-assisted laparoscopic technique for nephrectomy of large kidneys (> 2500 g) to encourage the use of laparoscopy for nephrectomy in autosomal dominant polycystic kidney disease.Methods: We retrospectively analyzed data from 26 nephrectomies in 17 patients who underwent HALN for ADPKD and compared them to a group of 22 nephrectomies in 18 patients with open surgical technique.
    Results: The duration of the procedure was significantly longer in the laparoscopic group, with a median of 180 minutes versus 90 minutes for the unilateral nephrectomies, and 240 minutes versus 122 minutes for the bilateral procedures. The median kidney weight in the open group was 2500 g (range 1300 - 4500 g), while the median weight in the HALN group was 2375 g (range 1000 - 4700 g). The median hospital stay was comparable. No significant differences were recorded in the intra- and postoperative complication rate.
    Conclusion: Hand-assisted laparoscopic nephrectomy can be considered a technique of choice for patients suffering from ADPKD requiring nephrectomy, also with massive kidneys weighing more than 3500 g. Compared to open nephrectomy, HALN can be performed safely, with reasonably longer operating times and without major complications, and offers a significant reduction in hospitalization time, pain and postoperative discomfort.
    Keywords:  Autosomal dominant polycystic Kidney disease (ADPKD); Bilateral nephrectomy; Hand-assisted laparoscopic nephrectomy; Laparoscopic nephrectomy; Polycystic kidneys
  9. Cytoskeleton (Hoboken). 2021 Apr 19.
      Motile cilia (also interchangeably called "flagella") are conserved organelles extending from the surface of many animal cells and play essential functions in eukaryotes including cell motility and environmental sensing. Large motor complexes, the ciliary dyneins, are present on ciliary outer-doublet microtubules and drive movement of cilia. Ciliary dyneins are classified into two general types; the outer dynein arms (ODAs) and the inner dynein arms (IDAs). While ODAs are important for generation of force and regulation of ciliary beat frequency, IDAs are essential for control of the size and shape of the bend, features collectively referred to as waveform. Also, recent studies have revealed unexpected links between IDA components and human diseases. In spite of their importance, however, studies on IDAs have been difficult since they are very complex and composed for several types of IDA motors, each unique in composition and location in the axoneme. Thanks in part to genetic, biochemical and structural analysis of Chlamydomonas reinhardtii, we are beginning to understand the organization and function of the ciliary IDAs. In this review, we summarize the composition of Chlamydomonas IDAs particularly focusing on each subunit, and discuss the assembly, conservation, and functional role(s) of these IDA subunits. Further, we raise several additional questions/challenges regarding IDAs, and discuss future perspectives of IDA studies. This article is protected by copyright. All rights reserved.
    Keywords:  Chlamydomonas; IDA; cilia; flagella; inner-arm dynein; motility; subunit
  10. Cell Rep. 2021 Apr 20. pii: S2211-1247(21)00333-8. [Epub ahead of print]35(3): 109019
      Reversible differentiation of vascular smooth muscle cells (VSMCs) plays a critical role in vascular biology and disease. Changes in VSMC differentiation correlate with stiffness of the arterial extracellular matrix (ECM), but causal relationships remain unclear. We show that VSMC plasticity is mechanosensitive and that both the de-differentiated and differentiated fates are promoted by the same ECM stiffness. Differential equations developed to model this behavior predicted that a null VSMC state generates the dual fates in response to ECM stiffness. Direct measurements of cellular forces, proliferation, and contractile gene expression validated these predictions and showed that fate outcome is mediated by Rac-Rho homeostasis. Rac, through distinct effects on YAP and TAZ, is required for both fates. Rho drives the contractile state alone, so its level of activity, relative to Rac, drives phenotypic choice. Our results show how the cellular response to a single ECM stiffness generates bi-stability and VSMC plasticity.
    Keywords:  MKL; YAP/TAZ; computational simulation; contractile force; differentiation; emergent behavior; mathematical modeling; mechanotransduction; proliferation
  11. Clin Exp Nephrol. 2021 Apr 21.
      BACKGROUND: Disease-specific trajectories of renal function in advanced chronic kidney disease (CKD) are not well defined. Here, we compared these trajectories in the estimated glomerular filtration rate (eGFR) by CKD stages.METHODS: Patients with multiple eGFR measurements during the 5-year preregistration period of the REACH-J study were enrolled. Mean annual eGFR declines were calculated from linear mixed effect models with the adjustment variables of baseline CKD stage, age, sex and the current CKD stage and the level of proteinuria (CKDA1-3).
    RESULTS: Among 1,969 eligible patients with CKDG3b-5, the adjusted eGFR decline (ml/min/1.73 m2/year) was significantly faster in diabetic kidney disease (DKD) patients and polycystic kidney disease (PKD) patients than in patients with other kidney diseases (DKD, - 2.96 ± 0.13; PKD, - 2.82 ± 0.17; and others, - 1.95 ± 0.05, p < 0.01). The declines were faster with higher CKD stages. In DKD patients, the eGFR decline was significantly faster in CKDG5 than CKDG4 (- 4.10 ± 0.18 vs - 2.76 ± 0.20, p < 0.01), while these declines in PKD patients were similar. The eGFR declines in PKD patients were significantly faster than DKD patients in CKDG4 (- 2.92 ± 0.23 vs - 2.76 ± 0.20, p < 0.01) and in CKDA2 (- 3.36 ± 0.35 vs - 1.40 ± 0.26, p < 0.01).
    CONCLUSION: Our study revealed the disease-specific annual eGFR declines by CKD stages and the level of proteinuria. Comparing to the other kidney diseases, the declines in PKD patients were getting faster from early stages of CKD. These results suggest the importance of CKD managements in PKD patients from the early stages.
    Keywords:  Diabetic kidney disease; EGFR decline; Polycystic kidney disease; REACH-J
  12. Acta Biomater. 2021 Apr 18. pii: S1742-7061(21)00267-1. [Epub ahead of print]
      Nasal inflammatory diseases, including nasal polyps and acute/chronic sinusitis, are characterized by impaired mucociliary clearance and eventually inflammation and infection. Contact of nasal polyps with adjacent nasal mucosa or stagnated mucus within the maxillary sinus produces compressive mechanical stresses on the apical surface of epithelium which can induce cytoskeleton remodeling in epithelial cells. In this study, we hypothesized that compressive stress modulates ciliary beating by altering the mechanical properties of the cytoskeleton of ciliated cell basal bodies. For the primary human nasal epithelial cells, we found that the applied compressive stress higher than the critical value of 1.0 kPa increased the stroke speed of cilia leading to the enhancement of ciliary beating frequency and mucociliary transportability. Immunostained images of the cytoskeleton showed reorganization and compactness of the actin filaments in the presence of compressive stress. Analysis of beating trajectory with the computational modeling for ciliary beating revealed that the stroke speed of cilium increased as the relative elasticity to viscosity of the surrounding cytoskeleton increases. These results suggest that the compressive stress on epithelial cells increases the ciliary beating speed through cytoskeleton remodeling to prevent mucus stagnation at the early stage of airway obstruction. Our study provides an insight into the defensive mechanism of airway epithelium against pathological conditions. STATEMENT OF SIGNIFICANCE: Cilia dynamics of the nasal epithelium is critical for not only maintaining normal breathing but preventing inflammatory diseases. It has been shown that mechanical compressive stresses can alter the shape and phenotype of epithelial cells. However, the effect of compressive stress on cilia dynamics is unclear. In this study, we demonstrated that the oscillation speed of cilia in human nasal epithelial cells was increased by the applied compressive stress experimentally. The computational simulation revealed that the change of ciliary beating dynamics was attributed to the viscoelastic properties of the reorganized cytoskeleton in response to compressive stress. Our results will be beneficial in understanding the defensive mechanism of airway epithelium against pathological conditions.
    Keywords:  Compressive stress; airway epithelial cell; ciliary beating; cilium model; cytoskeleton remodeling
  13. Neurosci Lett. 2021 Apr 15. pii: S0304-3940(21)00280-9. [Epub ahead of print] 135902
      Glaucoma is a progressive optic neuropathy in more than 25% of cases in patients with permanent blindness. The microRNA is implicated in modulating the cellular function of the trabecular meshwork (TM). The aim of this study is to investigate the role of miR-137 in glaucoma and illustrate the potential molecular mechanisms. We show that miR-137 was down-regulated in H2O2-induced human trabecular meshwork cells (HTMCs), and overexpression of miR-137 attenuated H2O2-induced cell growth inhibition, apoptosis and elevated extracellular matrix (ECM) protein expression. In addition, miR-137 blocked the activation of YAP/TAZ by directly targeting src. Overexpression of src or activation of the YAP/TAZ pathway partly abrogated the effects of miR-137 on H2O2-induced cell viability and apoptosis and dampened the inhibition effect on ECM protein expression. In conclusion, miR-137 promotes cell growth and inhibits extracellular matrix protein expression in H2O2-induced human trabecular meshwork cells via the YAP/TAZ pathway by targeting src. Hence, miR-137 might be used as a novel therapeutic target to treat glaucoma.
    Keywords:  Extracellular matrix; Glaucoma; Oxidative stress; miR-137
  14. Front Physiol. 2021 ;12 645044
      Non-reversible fibrosis is common in various diseases such as chronic renal failure, liver cirrhosis, chronic pancreatitis, pulmonary fibrosis, rheumatoid arthritis and atherosclerosis. Transforming growth factor beta 1 (TGF-β1) is involved in virtually all types of fibrosis. We previously described the involvement of Ras GTPase isoforms in the regulation of TGF-β1-induced fibrosis. The guanine nucleotide exchange factor Son of Sevenless (Sos) is the main Ras activator, but the role of the ubiquitously expressed Sos1 in the development of fibrosis has not been studied. For this purpose, we isolated and cultured Sos1 knock-out (KO) mouse embryonic fibroblasts, the main extracellular matrix proteins (ECM)-producing cells, and we analyzed ECM synthesis, cell proliferation and migration in the absence of Sos1, as well as the role of the main Sos1-Ras effectors, Erk1/2 and Akt, in these processes. The absence of Sos1 increases collagen I expression (through the PI3K-Akt signaling pathway), total collagen proteins, and slightly increases fibronectin expression; Sos1 regulates fibroblast proliferation through both PI3K-Akt and Raf-Erk pathways, and Sos1-PI3K-Akt signaling regulates fibroblast migration. These study shows that Sos1 regulates ECM synthesis and migration (through Ras-PI3K-Akt) and proliferation (through Ras-PI3K-Akt and Ras-Raf-Erk) in fibroblasts, and describe for the first time the role of the Sos1-Ras signaling axis in the regulation of cellular processes involved in the development of fibrosis.
    Keywords:  Akt; ERK; Sos1; extracellular matrix synthesis (ECM); fibroblasts; fibrosis; migration; proliferation
  15. Trends Cell Biol. 2021 Apr 15. pii: S0962-8924(21)00066-0. [Epub ahead of print]
      Delta (δ-) and epsilon (ε-) tubulin are lesser-known cousins of alpha (α-) and beta (β-) tubulin. They are likely to regulate centriole function in a broad range of species; however, their in vivo role and mechanism of action in mammals remain mysterious. In unicellular species and mammalian cell lines, mutations in δ- and ε-tubulin cause centriole destabilization and atypical mitosis and, in the most severe cases, cell death. Beyond the centriole, δ- and ε-tubulin localize to the manchette during murine spermatogenesis and interact with katanin-like 2 (KATNAL2), a protein with microtubule (MT)-severing properties, indicative of novel non-centriolar functions. Herein we summarize the current knowledge surrounding δ- and ε-tubulin, identify pathways for future research, and highlight how and why spermatogenesis and embryogenesis are ideal systems to define δ- and ε-tubulin function in vivo.
    Keywords:  basal body; centriole; delta tubulin; embryogenesis; epsilon tubulin; spermatogenesis
  16. Front Cell Dev Biol. 2021 ;9 624089
      LUZP1 is a centrosomal and actin cytoskeleton-localizing protein that regulates both ciliogenesis and actin filament bundling. As the cytoskeleton and cilia are implicated in metastasis and tumor suppression, we examined roles for LUZP1 in the context of cancer. Here we show that LUZP1 exhibits frequent genomic aberrations in cancer, with a predominance of gene deletions. Furthermore, we demonstrate that CRISPR/Cas9-mediated loss of Luzp1 in mouse fibroblasts promotes cell migration and invasion features, reduces cell viability, and increases cell apoptosis, centriole numbers, and nuclear size while altering the actin cytoskeleton. Loss of Luzp1 also induced changes to ACTR3 (Actin Related Protein 3, also known as ARP3) and phospho-cofilin ratios, suggesting regulatory roles in actin polymerization, beyond its role in filament bundling. Our results point to an unprecedented role for LUZP1 in the regulation of cancer features through the control of actin cytoskeleton.
    Keywords:  LUZP1; actin cytoskeleton; cancer; centrosome; invasion; migration; proliferation
  17. Auris Nasus Larynx. 2021 Mar 31. pii: S0385-8146(21)00087-0. [Epub ahead of print]
      An 11-month-old boy with productive cough was referred to our hospital. He had nasal obstruction immediately after birth, and wheezing, wet cough, and rhinorrhea were observed daily after the neonatal period. Clinical and imaging findings revealed secretory otitis media, chronic sinusitis, and bronchiectasis. Primary ciliary dyskinesia was suspected. Transmission electron microscopy of nasal cilia showed defects of the outer and inner dynein arms. Genetic examinations of the family revealed copy number variation in PIH1 domain-containing 3 (PIH1D3) in the proband and mother. This is the first report of a Japanese patient with primary ciliary dyskinesia caused by copy number variation in PIH1D3.
    Keywords:  Copy number variation; PIH1D3; Whole exome sequencing; X-linked inheritance; gene
  18. Int Arch Allergy Immunol. 2021 Apr 21. 1-7
      BACKGROUND: The ciliary beat of the airway epithelium, including the sinonasal epithelium, has a significant role in frontline defense and is thought to be controlled by the level of intracellular Ca2+. Involvement of calmodulin and adenylate/guanylate cyclases in the regulation of ciliary beats has been reported, and here we investigated the interrelation between these components of the ciliary beat regulatory pathway.METHODS: The inferior turbinates were collected from 29 patients with chronic hypertrophic rhinitis/rhinosinusitis during endoscopic sinonasal surgery. The turbinate mucosa was cut into thin strips, and mucociliary movement was observed under a phase-contrast light microscope equipped with a high-speed digital video camera.
    RESULTS: The ciliary beat frequency (CBF) was significantly increased by stimulation with 100 μM CALP3 (calmodulin agonist), which was completely suppressed by adding 100 µM SQ22536 (adenylate cyclase inhibitor) and 10 µM ODQ (guanylate cyclase inhibitor) together and by adding 1 µM KT5720 (protein kinase A inhibitor) and 1 µM KT5823 (protein kinase G inhibitor) together. The CBF was significantly increased by stimulation with 10 µM forskolin (adenylate cyclase activator) and 10 µM BAY41-2272 (guanylate cyclase activator) and by stimulation with 100 µM 8-bromo-cAMP (cAMP analog) and 100 µM 8-bromo-cGMP (cGMP analog), which was not changed by adding 1 µM calmidazolium (calmodulin antagonist).
    CONCLUSIONS: These results confirmed that the regulatory pathway of ciliary beats in the human nasal mucosa involves calmodulin, adenylate/guanylate cyclases, and protein kinases A/G and indicate that adenylate/guanylate cyclases and protein kinases A/G act downstream of calmodulin, but not vice versa, and that these cyclases relay calmodulin signaling.
    Keywords:  Adenylate/guanylate cyclases; Calmodulin; Ciliary beat; Nasal mucosa; Protein kinases A/G
  19. J Ethnopharmacol. 2021 Apr 20. pii: S0378-8741(21)00288-9. [Epub ahead of print] 114061
      ETHNOPHARMACOLOGICAL RELEVANCE: The abnormal proliferation and differentiation of cardiac fibroblasts (CFs) are universally regarded as the key process for the progressive development of cardiac fibrosis following various cardiovascular diseases. Huoxin Pill (Concentrated pill, HXP) is a Chinese herbal formula for treating coronary heart disease. However, the cellular and molecular mechanisms of HXP in the treatment of myocardial fibrosis are still unclear.AIM OF THE STUDY: To investigate the effects of HXP on CFs transdifferentiation and collagen synthesis under isoproterenol (ISO) conditions, as well as the potential mechanism of action.
    MATERIALS AND METHODS: In vivo, we established a rat model of cardiac fibrosis induced by ISO, and administered with low or high dose of HXP (10 mg/kg/day or 30 mg/kg/day). The level of α-SMA was detected by immunohistochemistry examination, and combined with RNA-sequencing analysis to determine the protective effect of HXP on myocardial fibrosis rats. In vitro, by culturing primary rat CFs, we examined the effects of HXP on the proliferation and transdifferentiation of CFs using CCK8, scratch wound healing and immunofluorescence assays. Western blot was used to determine protein expression.
    RESULTS: The findings revealed that HXP protects against ISO-induced cardiac fibrosis and CFs transdifferentiation in rats. RNA-sequencing and pathway analyses demonstrated 238 or 295 differentially expressed genes (DEGs) and multiple enriched signal pathways, including transforming growth factor-beta (TGF-β) receptor signaling activates Smads, downregulation of TGF-β receptor signaling, signaling by TGF-β receptor complex, and collagen formation under treatment with low or high-dose of HXP. Moreover, HXP also markedly inhibited ISO-induced primary rat CFs proliferation, transdifferentiation, collagen synthesis and the upregulation of TGF-β1 and phosphorylated Smad2/3 protein expression.
    CONCLUSION: HXP suppresses ISO-induced CFs transdifferentiation and collagen synthesis, and it may exert these effects in part by inhibiting the activation of the TGF-β/Smads pathway. This may be a new therapeutic tool for cardiac fibrosis.
    Keywords:  Huoxin Pill; TGF-β/Smads pathway; cardiac fibroblasts; cardiac fibrosis; isoproterenol; transdifferentiation
  20. Comput Methods Programs Biomed. 2021 Apr 08. pii: S0169-2607(21)00146-2. [Epub ahead of print]205 106071
      BACKGROUND AND OBJECTIVE: The primary causes of kidney failure are chronic and polycystic kidney diseases. Cyst, stone, and tumor development lead to chronic kidney diseases that commonly impair kidney functions. The kidney diseases are asymptomatic and do not show any significant symptoms at its initial stage. Therefore, diagnosing the kidney diseases at their earlier stage is required to prevent the loss of kidney function and kidney failure.METHODS: This paper proposes a computer-aided diagnosis (CAD) system for detecting multi-class kidney abnormalities from ultrasound images. The presented CAD system uses a pre-trained ResNet-101 model for extracting the features and support vector machine (SVM) classifier for the classification purpose. Ultrasound images usually gets affected by speckle noise that degrades the image quality and performance of the CAD system. Hence, it is necessary to remove speckle noise from the ultrasound images. Therefore, a CAD based system is proposed with the despeckling module using a deep residual learning network (RLN) to reduce speckle noise. Pre-processing of ultrasound images using deep RLN helps to drastically improve the classification performance of the CAD system. The proposed CAD system achieved better prediction results when compared to the existing state-of-the-art methods.
    RESULTS: To validate the proposed CAD system performance, the experiments have been carried out in the noisy kidney ultrasound images. The designed system framework achieved the maximum classification accuracy when compared to the existing approaches. The SVM classifier is selected for the CAD system based on performance comparison with various classifiers like K-nearest neighbour, tree, discriminant, Naive Bayes, and linear.
    CONCLUSIONS: The proposed CAD system outperforms in classifying the noisy kidney ultrasound images precisely as compared to the existing state-of-the-art methods. Further, the CAD system is evaluated in terms of selectivity and sensitivity scores. The presented CAD system with the pre-processing module would serve as a real-time supporting tool for diagnosing multi-class kidney abnormalities from the ultrasound images.
    Keywords:  Classification; Deep neural networks; Despeckling; Residual learning network
  21. Front Cell Dev Biol. 2021 ;9 624531
      The left-right (LR) field recognizes the importance of the mechanism involving the calcium permeable channel Polycystin-2. However, whether the early LR symmetry breaking mechanism is exclusively via Polycystin-2 has not been tested. For that purpose, we need to be able to isolate the effects of decreasing the levels of Pkd2 protein from any eventual effects on flow dynamics. Here we demonstrate that curly-up (cup) homozygous mutants have abnormal flow dynamics. In addition, we performed one cell stage Pkd2 knockdowns and LR organizer specific Pkd2 knockdowns and observed that both techniques resulted in shorter cilia length and abnormal flow dynamics. We conclude that Pkd2 reduction leads to LR defects that cannot be assigned exclusively to its putative role in mediating mechanosensation because indirectly, by modifying cell shape or decreasing cilia length, Pkd2 deficit affects LR flow dynamics.
    Keywords:  Pkd2; cilia length; dand5; flow dynamics; left-right; zebrafish
  22. Transpl Int. 2021 Apr 21.
      INTRODUCTION: Heart transplantation is a viable option for end stage heart disease but long-term complications such as chronic kidney disease are being increasingly recognized. We sought to investigate the effect of change in estimated glomerular filtration rate (eGFR) during the heart transplant waitlist period on post-transplant mortality and end stage kidney disease (ESKD).METHODS: We analyzed the United Network of Organ Sharing heart transplant database from 2000-2017. Multivariable Cox regression with restricted cubic splines and cumulative incidence competing risk (CICR) methods were used to compare the effects of change in eGFR on mortality and ESKD, respectively.
    RESULTS: 19412 patients met our inclusion criteria. Mortality increased with increasing loss of eGFR (adjusted hazard ratio increased from 1.02 (confidence interval (CI) 1.01-1.04, p=0.008) for 10% loss to 1.15 (CI 1.06-1.26, p=0.001) for 50% loss of eGFR. Similarly, risk of ESKD also increased monotonically with increasing loss of renal function (subdistribution hazard ratio increased from 1.12 (CI 1.09-1.14, p<0.001) to 2.0 (CI 1.74-2.3, p<0.001)) as loss of eGFR increased from 10% to 50%.
    CONCLUSION: Overall, we found that loss of >10% of eGFR resulted in higher risk of mortality and higher risk of ESKD.
    Keywords:  Chronic kidney disease; Complications < Heart Clinical; Heart Clinical; Outcome < Heart Clinical; Waitlist; change in renal function; estimated glomerular filtration rate
  23. Gastroenterol Hepatol (N Y). 2020 Jan;16(1): 39-41
  24. Nephrol Dial Transplant. 2020 Dec 01. pii: gfaa252. [Epub ahead of print]
      BACKGROUND: The optimal level of salt intake remains ill-defined in non-dialysis chronic kidney disease (CKD) patients under regular nephrology care. This unanswered question becomes critical in older patients who are exposed to higher risk of worsening of cardiorenal disease due to volemic changes.METHODS: In this pooled analysis of four prospective studies in CKD, we compared the risk of all-cause mortality and end-stage kidney disease (ESKD) between patients ≤65 and >65 years of age stratified by salt intake level (<6, 6-8 and >8 g/day) estimated from two measurements of 24-h urinary sodium.
    RESULTS: The cohort included 1785 patients. The estimated glomerular filtration rate was 37 ± 21 mL/min/1.73 m2 overall, 41 ± 25 in younger patients and 34 ± 16 in older patients (P < 0.001). The median 24-h urinary sodium excretion was 143 mEq [interquartile range (IQR) 109-182] in all, 147 (112-185) in younger patients and 140 (106-179) in older patients (P = 0.012). Salt intake was ≤6, 6-8 and >8 g sodium chloride/day in 21.9, 26.2 and 52.0% of older patients and 18.6, 25.2 and 56.2% in younger patients, respectively (P = 0.145). During a median follow-up of 4.07 years we registered 383 ESKD and 260 all-cause deaths. In the whole cohort, the risks of ESKD and all-cause death did not differ by salt intake level. In older patients, ESKD risk [multi-adjusted hazard ratio (HR) and 95% confidence interval (CI)] was significantly lower at salt intakes of 6-8 g/day [HR 0.577 (95% CI 0.361-0.924)] and >8 g/day [HR 0.564 (95% CI 0.382-0.833)] versus the reference group (<6 g/day). Mortality risk was higher in older versus younger patients, with no difference across salt intake categories. No effect of salt intake on ESKD and mortality was observed in younger patients.
    CONCLUSIONS: CKD patients under nephrology care show a moderate salt intake (8.4 g/day) that is lower in older versus younger patients. In this context, older patients are not exposed to higher mortality across different levels of salt intake, while salt intake <6 g/day poses a greater risk of ESKD.
    Keywords:  CKD; ESKD; mortality; salt intake