bims-bicyki Biomed News
on Bicaudal-C1 and interactors in cystic kidney disease
Issue of 2022–03–06
seventeen papers selected by
Céline Gagnieux, École Polytechnique Fédérale de Lausanne



  1. BMC Nephrol. 2022 Mar 03. 23(1): 85
       BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary kidney disease. Defect in cilia-mediated signaling activity is a crucial factor leading to cyst formation. Hence, ADPKD is regarded as a systemic disorder with multiple extrarenal complications, including cysts in other organs, for instance, the liver, pancreas, spleen, or ovaries. Interestingly, loss-of-function of primary cilia has been recently found to contribute to a malignant transformation from degenerated thyroid follicles. However, the increased incidence of thyroid nodules in ADPKD patients has not yet been fully confirmed.
    OBJECTIVES: To determine the incidence of thyroid lesions in patients with ADPKD in comparison to previous population studies. Moreover, we aimed to investigate if the pace of the disease progression is associated with a higher prevalence of thyroid lesions.
    MATERIAL AND METHODS: In 49 early-stage ADPKD patients recruited from our center, we performed ultrasonography of the thyroid glands, and laboratory evaluation of thyroids function. We compared the results with population studies.
    RESULTS: Twenty-three individuals had solid, cystic-solid, or cystic lesions revealed in the ultrasonography and 2 patients had a positive past medical history for thyroidectomy due to nodular goiter. In 10 patients out of the 23, only minor cysts with no clinical significance were found and 13 out of the 23 patients had solid or cystic-solid lesions, which occurred to be benign based on three years of follow-up or the biopsy of the nodule.
    CONCLUSIONS: We found no increased incidence of thyroid gland lesions in early ADPKD patients in comparison to previous population studies. Plausibly, mechanisms other than defective cilia signaling are involved in the risk for focal thyroid lesions formation. Moreover, the rate of progression of kidney function decline seems to be not accompanied by the higher incidence of thyroid pathology.
    Keywords:  ADPKD; Polycystic kidney disease; Thyroid nodules; Ultrasonography
    DOI:  https://doi.org/10.1186/s12882-022-02714-w
  2. Nutr Hosp. 2022 Mar 04.
       INTRODUCTION: total kidney volume (TKV) increases in patients with autosomal dominant polycystic kidney disease (ADPKD), which perturbs anthropometric measurements.
    OBJECTIVES: the primary objectives were to investigate the accuracy of waist circumference (WC) and waist-to-hip ratio (WHR) for determining abdominal obesity in patients with ADPKD by comparison with magnetic resonance images. The secondary objectives were to investigate the associations of energy/macronutrient intake with WC and WHR.
    METHODS: sixty patients with ADPKD were recruited from a nephrology outpatient clinic in this cross-sectional study. Main outcome measures were: TKV, total subcutaneous fat (TSF), total intraperitoneal fat (TIF), WC, WHR, body mass index (BMI), skinfold thickness (SFT), and energy/macronutrient intake.
    RESULTS: mean age was 48.6 ± 11.3 years, 38 of 60 were women, median TKV was 1486 (IQR, 981-2847) mL. The patients classed as obese by the BMI had higher WC, TSF, TIF, and SFT than did non-obese; however, WHR was similar in obese and non-obese men. In the all-patients group, the WHR of obese and non-obese patients were also similar. TKV was positively correlated with WC and WHR in women, but not in men. In the multivariate analysis, TKV was an independent factor affecting WC and WHR in women. Dietary fat intake was similar in groups with and without abdominal obesity according to WC and WHR.
    CONCLUSIONS: in women with ADPKD, WC and WHR may not be accurate anthropometric measurements for evaluation of abdominal obesity; however, they may be associated with TKV.
    DOI:  https://doi.org/10.20960/nh.03976
  3. Biochim Biophys Acta Mol Basis Dis. 2022 Feb 23. pii: S0925-4439(22)00034-5. [Epub ahead of print] 166371
      Cardiovascular manifestations account for marked morbi-mortality in autosomal dominant polycystic kidney disease (ADPKD). Pkd1- and Pkd2-deficient mice develop cardiac dysfunction, however the underlying mechanisms remain largely unclear. It is unknown whether impairment of polycystin-1 cleavage at the G-protein-coupled receptor proteolysis site, a significant ADPKD mutational mechanism, is involved in this process. We analyzed the impact of polycystin-1 cleavage on heart metabolism using Pkd1V/V mice, a model unable to cleave this protein and with early cardiac dysfunction. Pkd1V/V hearts showed lower levels of glucose and amino acids and higher lipid levels than wild-types, as well as downregulation of p-AMPK, p-ACCβ, CPT1B-Cpt1b, Ppara, Nppa and Acta1. These findings suggested decreased fatty acid β-oxidation, which was confirmed by lower oxygen consumption by Pkd1V/V isolated mitochondria using palmitoyl-CoA. Pkd1V/V hearts also presented increased oxygen consumption in response to glucose, suggesting that alternative substrates may be used to generate energy. Pkd1V/V hearts displayed a higher density of decreased-size mitochondria, a finding associated with lower MFN1, Parkin and BNIP3 expression. These derangements were correlated with increased apoptosis and inflammation but not hypertrophy. Notably, Pkd1V/V neonate cardiomyocytes also displayed shifts in oxygen consumption and p-AMPK downregulation, suggesting that, at least partially, the metabolic alterations are not induced by kidney dysfunction. Our findings reveal that disruption of polycystin-1 cleavage leads to cardiac metabolic rewiring in mice, expanding the understanding of heart dysfunction associated with Pkd1 deficiency and likely with human ADPKD.
    Keywords:  Autosomal dominant polycystic kidney disease; Cardiac dysfunction; Lipid derangement; Metabolic rewiring; Mitochondria; Polycystin-1 cleavage at GPS
    DOI:  https://doi.org/10.1016/j.bbadis.2022.166371
  4. J Am Soc Nephrol. 2022 Mar 02. pii: ASN.2021081125. [Epub ahead of print]
      Background: Upregulation of cAMP-dependent and -independent PKA signaling is thought to promote cystogenesis in polycystic kidney disease (PKD). PKA-I regulatory subunit RIα is increased in kidneys of orthologous mouse models. Kidney-specific knockout of RIα upregulates PKA activity, induces cystic disease in wild-type mice, and aggravates it in Pkd1 RC/RC mice. Methods: PKA-I activation or inhibition was compared to EPAC activation or PKA-II inhibition using Pkd1 RC/RC metanephric organ cultures. The effect of constitutive PKA (preferentially PKA-I) downregulation in vivo was ascertained by kidney-specific expression of a dominant negative RIαB allele in Pkd1 RC/RC mice obtained by crossing Prkar1α R1αB/WT, Pkd1 RC/RC, and Pkhd1-Cre mice (C57BL/6 background). The effect of pharmacologic PKA inhibition using a novel, selective PRKACA inhibitor (BLU2864) was tested in mIMCD3 3D cultures, metanephric organ cultures, and Pkd1 RC/RC mice on a C57BL/6 x 129S6/Sv F1 background. Mice were sacrificed at 16 weeks of age. Results: PKA-I activation promoted and inhibition prevented ex vivo P-Ser133 CREB expression and cystogenesis. EPAC activation or PKA-II inhibition had no or only minor effects. BLU2864 inhibited in vitro mIMCD3 cystogenesis and ex vivo P-Ser133 CREB expression and cystogenesis. Genetic downregulation of PKA activity and BLU2864 directly and/or indirectly inhibited many pro-proliferative pathways and were both protective in vivo BLU2864 had no detectable on- or off-target adverse effects. Conclusions: PKA-I is the main PKA isozyme promoting cystogenesis. Direct PKA inhibition may be an effective strategy to treat PKD and other conditions where PKA signaling is upregulated. By acting directly on PKA, the inhibition may be more effective than or substantially increase the efficacy of treatments that only affect PKA activity by lowering cAMP.
    DOI:  https://doi.org/10.1681/ASN.2021081125
  5. Front Biosci (Landmark Ed). 2022 Feb 11. 27(2): 49
       BACKGROUND: Endothelial dysfunction plays a crucial role in diabetic vascular complications. A decrease in hydrogen sulfide (H2S) levels is increasingly becoming a vital factor contributing to high glucose (HG)-induced endothelial dysfunction. Dopamine D1-like receptors (DR1) activation has important physiological functions in the cardiovascular system. H2S decreases the dysfunction of vascular endothelial cells. However, no studies have reported whether DR1 protects the function of vascular endothelial cells by regulating H2S levels.
    AIM: The present study aimed to determine whether DR1 regulates the levels of endogenous H2S, which exerts protective effects against HG-induced injury of human umbilical vein endothelial cells (HUVECs) via Ras homolog gene family member A (RhoA)/Rho-associated coiled-coil containing kinase 1 (ROCK1) signalling.
    METHODS: HUVECs were exposed to HG (30 mM) or normal glucose (5.5 mM) after different treatments. Cell viability, proliferation and migration were measured by Cell Counting Kit-8, EdU cell proliferation assay, transwell assay and wound healing assay, respectively. H2S probe (7-Azido-4-Methylcoumarin) was used to detect levels of H2S. The intracellular calcium concentration ([Ca2+]i) were measured using Fluo-4 AM. The protein expressions were quantified by Western blot.
    RESULTS: We found that HG decreased the expression of DR1 and cystathionine γ-lyase (CSE) and H2S production. The DR1 agonist SKF38393 significantly increased DR1 and CSE expression and H2S production, whereas NaHS (a H2S donor) only increased CSE expression and H2S production but had no effect on DR1 expression. Meanwhile, SKF38393 further increased the [Ca2+]i induced by HG. In addition, HG reduced cell viability and the expression of Cyclin D1 and proliferating cell nuclear antigen and increased the expression of p21C⁢i⁢p/W⁢A⁢F-1, collagen I, collagen III, matrix metalloproteinase 9, osteopontin and α-smooth muscle actin and the activity of phosphorylated RhoA and ROCK1. SKF38393 and NaHS reversed these effects of HG. PPG (a CSE inhibitor) abolished the beneficial effect of SKF38393. These effects of SKF38393 were similar to those of Y-27632 (a ROCK inhibitor).
    CONCLUSION: Taken together, our results suggest that DR1 activation upregulates the CSE/H2S pathway by increasing the [Ca2+]i, which protects endothelial cells from HG-induced injury by inhibiting the RhoA/ROCK1 pathway.
    Keywords:  Dopamine D1-like receptors; Endothelial cells; High glucose; Hydrogen sulfide; RhoA/ROCK1 pathway
    DOI:  https://doi.org/10.31083/j.fbl2702049
  6. Biomol Ther (Seoul). 2022 Mar 01. 30(2): 170-178
      The airway epithelium is equipped with the ability to resist respiratory disease development and airway damage, including the migration of airway epithelial cells and the activation of TLR3, which recognizes double-stranded (ds) RNA. Primary cilia on airway epithelial cells are involved in the cell cycle and cell differentiation and repair. In this study, we used Beas-2B human bronchial epithelial cells to investigate the effects of the TLR3 agonist polyinosinic:polycytidylic acid [Poly(I:C)] on airway cell migration and primary cilia (PC) formation. PC formation increased in cells incubated under serum deprivation. Migration was faster in Beas-2B cells pretreated with Poly(I:C) than in control cells, as judged by a wound healing assay, single-cell path tracking, and a Transwell migration assay. No changes in cell migration were observed when the cells were incubated in conditioned medium from Poly(I:C)-treated cells. PC formation was enhanced by Poly(I:C) treatment, but was reduced when the cells were exposed to the ciliogenesis inhibitor ciliobrevin A (CilioA). The inhibition of Beas-2B cell migration by CilioA was also assessed and a slight decrease in ciliogenesis was detected in SARS-CoV-2 spike protein (SP)-treated Beas-2B cells overexpressing ACE2 compared to control cells. Cell migration was decreased by SP but restored by Poly(I:C) treatment. Taken together, our results demonstrate that impaired migration by SP-treated cells can be attenuated by Poly(I:C) treatment, thus increasing airway cell migration through the regulation of ciliogenesis.
    Keywords:  Airway epithelial cell; Beas-2B cell; Cell migration; Poly(I:C); Primary cilium
    DOI:  https://doi.org/10.4062/biomolther.2022.009
  7. Neoreviews. 2022 Mar 01. 23(3): e175-e188
      Fetal kidney development is a complex and carefully orchestrated process. The proper formation of kidney tissue involves many transcription factors and signaling pathways. Pathogenic variants in the genes that encodethese factors and proteins can result in neonatal cystic kidney disease. Advancements in genomic sequencing have allowed us to identify many of these variants and better understand the genetic underpinnings for an increasing number of presentations of childhood kidney disorders. This review discusses the genes essential in kidney development, particularly those involved in the structure and function of primary cilia, and implications of gene identification for prognostication and management of cystic kidney disorders.
    DOI:  https://doi.org/10.1542/neo.23-3-e175
  8. Vascul Pharmacol. 2022 Feb 25. pii: S1537-1891(22)00022-2. [Epub ahead of print] 106973
      Tolvaptan has been approved for the treatment of autosomal dominant polycystic kidney disease and heart failure. However, the role of tolvaptan in patients with abdominal aortic aneurysm (AAA) has not been examined. Human aortic smooth muscle cells (HASMCs) were used as the in vitro model. Via Ang II infusion, experimental AAAs were induced in Apo-E knockout mice. In vitro study showed that tolvaptan suppressed matrix metalloproteinase (MMP) expressions (MMP-2 and MMP-9) and apoptosis in Ang II-stimulated HASMCs. In the Apo-E knockout mice with Ang II-induced AAA, the animals exhibited AAA formation with elastic lamina degradation, dilatation of the suprarenal aorta, increased macrophage infiltration and higher expressions of MMPs. Treatment with a high dose of tolvaptan prevented experimental AAA formation while preserving the elastic lamina structure, reducing inflammatory macrophages, and inhibiting gelatinolytic activity, MMP expressions and apoptosis of SMCs in aorta tissue. Specifically, tolvaptan reduced the expression of receptor-interacting protein kinase 3 (RIP3) and decreased apoptosis of SMCs. Our data demonstrated that tolvaptan reduces experimental AAA formation and dissection by inhibiting destruction of the aortic structure integrity and reducing inflammatory macrophage infiltration, MMP-2 and MMP-9 expressions, and apoptosis of vascular SMCs, indicating tolvaptan may have therapeutic potential for AAA and dissection.
    Keywords:  Abdominal aortic aneurysm and dissection; Tolvaptan; Vasopressin type 2 antagonist
    DOI:  https://doi.org/10.1016/j.vph.2022.106973
  9. Mol Med Rep. 2022 May;pii: 155. [Epub ahead of print]25(5):
      Acute kidney injury (AKI) is the most common and serious complication of sepsis, and it is also the main cause of mortality in patients with sepsis. The G protein‑coupled receptor 55 (GPR55) inhibitor CID16020046 was found to suppress the inflammatory response in sepsis models in mice. The aim of the present study was to investigate the effect of CID16020046 on AKI in sepsis mouse models and elucidate the possible underlying mechanisms. A sepsis model in mice was established by cecal ligation/perforation (CLP). The expression levels of GPR55 in the serum of patients with sepsis and the renal tissues of septic mice were determined via reverse transcription‑quantitative PCR and western blot analyses, respectively. The pathological injury of renal tissue was evaluated using H&E and periodic acid‑Schiff staining. ELISA was performed to detect the levels of renal injury‑related factors, including blood urea nitrogen (BUN), creatinine (Cre), kidney injury molecule 1 (KIM1) and neutrophil gelatinase‑associated lipocalin (NGAL) in septic mice. Moreover, the levels of pro‑inflammatory cytokines (TNF‑α, IL‑6 and IL‑1β) were detected via ELISA and western blotting. Apoptosis was determined using TUNEL staining and western blotting. The expression levels of Rho‑associated protein kinase (ROCK) pathway‑related proteins (Ras homolog family member A, ROCK1 and ROCK2) was measured via western blotting. Finally, H&E staining was used to evaluate the effect of CID16020046 on various organs in mice. Compared with the control subjects, the expression level of GPR55 in the serum of patients with sepsis was significantly increased. Compared with the sham group, CID16020046 (20 mg/kg) significantly decreased the levels of BUN and Cre in the serum, as well as the contents of KIM1 and NGAL in the urine. Furthermore, CID16020046 significantly decreased the contents of TNF‑α, IL‑6 and IL‑1β in the serum and renal tissue of septic mice, and reduced cell apoptosis. In addition, CID16020046 effectively suppressed the expression levels of ROCK pathway‑related proteins, and H&E staining revealed that CID16020046 (20 mg/kg) had no toxic effect on the heart, liver, spleen or lung in normal mice. In conclusion, CID16020046 may prove useful for the development of drugs for the treatment of sepsis‑induced AKI.
    Keywords:  CID16020046; G protein-coupled receptor 55; acute kidney injury; sepsis
    DOI:  https://doi.org/10.3892/mmr.2022.12671
  10. Clin Pharmacol Drug Dev. 2022 Mar 01.
      Belumosudil is a selective Rho-associated coiled-coil containing protein kinase 2 (ROCK2) inhibitor. ROCK2 has been shown to drive proinflammatory response and fibrosis that occurs with chronic graft-versus-host disease; therefore, inhibition of ROCK2 has emerged as a therapeutic target for chronic graft-versus-host disease. In this phase 1 two-part study, the pharmacokinetics, mass balance, and metabolic profile of belumosudil were evaluated after single doses of unlabeled belumosudil oral tablets (200 mg), radiolabeled belumosudil intravenous (IV) microtracer infusions (100 μg), and radiolabeled oral capsules (200 mg). Absolute bioavailability based on area under the plasma concentration-time curve from time 0 to infinity for the oral dose/area under the plasma concentration-time curve from time 0 to infinity for the IV dose was calculated as 63.7%. Radiolabeled IV microtracer dosing demonstrated a low extraction ratio and distribution of belumosudil into tissues. The majority of total radioactivity was recovered in feces, with minimal amounts recovered in urine, suggesting minimal renal elimination of belumosudil. In addition to parent and main metabolite KD025m2, metabolites identified in plasma included the phase 2 metabolites O-dealkylated belumosudil sulfate and belumosudil glucuronide. These metabolites (with the exception of the glucuronide) in addition to monohydroxy-belumosudil, and belumosudil diol were identified in feces. No metabolites in urine accounted for >10% of the radioactive dose.
    Keywords:  AME; graft-versus-host disease; metabolite profiling; pharmacokinetics
    DOI:  https://doi.org/10.1002/cpdd.1085
  11. J Cardiovasc Pharmacol. 2022 Feb 24.
       ABSTRACT: Activation of adventitial fibroblasts (AFs) upon vascular injury contributes to vascular remodeling. Hydrogen sulfide (H2S), a gaseous signal molecule, modulates various cardiovascular functions. The aim of this study was to explore whether exogenous H2S ameliorates transforming growth factor-β1 (TGF-β1) induced activation of adventitial fibroblasts (AFs), and if so, to determine the underlying molecular mechanisms. Immunofluorescent staining, and western blot were employed to determine the expression of collagen I and α-smooth muscle-actin (α-SMA). The proliferation and migration of AFs were performed by using cell counting kit-8 (CCK-8) and Transwell assay, respectively. The mitochondrial morphology was assessed by MitoTracker Red staining. The activation of signaling pathway was evaluated by western blot. The mitochondrial reactive oxygen species (mtROS) and mitochondrial membrane potential were determined by MitoSOX and JC-1 (5,5',6,6'-tetrachloro-1,1,3,3'-tetraethylbenzimidazolyl carbocyanine iodide) staining. Our study demonstrated exogenous H2S treatment dramatically suppressed TGF-β1 induced AF proliferation, migration, and phenotypic transition by blockage of dynamin-related protein 1 (Drp1) mediated mitochondrial fission and regulated mtROS generation. Moreover, exogenous H2S reversed TGF-β1 induced mitochondrial fission and AF activation by modulating Rho-associated protein kinase 1 (ROCK1) dependent phosphorylation of Drp1. In conclusion, our results suggested that exogenous H2S attenuates TGF-β1 induced AF activation via suppression of Drp1-mediated mitochondrial fission in a ROCK1-dependent fashion.
    DOI:  https://doi.org/10.1097/FJC.0000000000001250
  12. Transplant Proc. 2022 Mar 01. pii: S0041-1345(22)00093-8. [Epub ahead of print]
       BACKGROUND: Preemptive kidney transplant (PKT) is recognized as the most beneficial and cost-effective form of renal replacement therapy among patients with end-stage renal disease. Despite optimal outcomes and improved quality of life associated with PKT, its use as a first renal replacement therapy remains low among patients with end-stage renal disease. The goal of this retrospective cohort study was to compare, among adult kidney transplant recipients, characteristics across PKT status.
    METHODS: We compared the characteristics of patients who did and did not have a PKT over 5 years, from 2010 to 2014, using the electronic health records of Kaiser Permanente Mid-Atlantic States.
    RESULTS: A total of 233 patients received a kidney-alone transplant, and, of these, 44 patients (19%) were PKT and 189 patients (81%) were non-PKT. Of the patients in the PKT group, 43% received a kidney from a deceased donor. PKT recipients were more often White, had polycystic kidney disease or glomerulonephritis, received a living donor organ, and were transplanted at certain transplant centers. Estimated glomerular filtration rate on listing for those who received a deceased donor transplant was higher in PKT than non-PKT patients listed pre-dialysis.
    CONCLUSIONS: PKT was associated with having a living kidney donor and with having a higher estimated glomerular filtration rate at listing for deceased donor recipients.
    DOI:  https://doi.org/10.1016/j.transproceed.2021.11.038
  13. Clin Chest Med. 2022 Mar;pii: S0272-5231(21)01246-6. [Epub ahead of print]43(1): 127-140
      Primary ciliary dyskinesia (PCD) is a rare genetic disease leading to bronchiectasis in most patients. In addition to the lungs, PCD might affect multiple organ systems, and patients frequently have multiple clinical problems, which require multidisciplinary management. Diagnosis of PCD needs a combination of tests, many of which require expertise and expensive equipment. Measurement of nasal nitric oxide is the first test to consider when PCD is suspected. Detailed clinical history using available predictive scores in combination with information on functional and structural aspects of lung disease is important to identify which patients should be referred for further diagnostic testing.
    Keywords:  Bronchiectasis; Diagnosis; Management; Monitoring; Primary ciliary dyskinesia
    DOI:  https://doi.org/10.1016/j.ccm.2021.11.008
  14. Elife. 2022 Mar 01. pii: e74765. [Epub ahead of print]11
      Polycystin-1 (PC-1, PKD1), a receptor-like protein expressed by the Pkd1 gene, is present in a wide variety of cell types, but its cellular location, signaling mechanisms and physiological functions are poorly understood. Here, by studying tamoxifen-inducible, endothelial cell (EC)-specific Pkd1 knockout (Pkd1 ecKO) mice, we show that flow activates PC-1-mediated, Ca2+-dependent cation currents in ECs. EC-specific PC-1 knockout attenuates flow-mediated arterial hyperpolarization and vasodilation. PC-1-dependent vasodilation occurs over the entire functional shear stress range and via the activation of endothelial nitric oxide synthase (eNOS) and intermediate (IK)- and small (SK)-conductance Ca2+-activated K+ channels. EC-specific PC-1 knockout increases systemic blood pressure without altering kidney anatomy. PC-1 coimmunoprecipitates with polycystin-2 (PC-2, PKD2), a TRP polycystin channel, and clusters of both proteins locate in nanoscale proximity in the EC plasma membrane. Knockout of either PC-1 or PC-2 (Pkd2 ecKO mice) abolishes surface clusters of both PC-1 and PC-2 in ECs. Single knockout of PC-1 or PC-2 or double knockout of PC-1 and PC-2 (Pkd1/Pkd2 ecKO mice) similarly attenuates flow-mediated vasodilation. Flow stimulates non-selective cation currents in ECs that are similarly inhibited by either PC-1 or PC-2 knockout or by interference peptides corresponding to the C-terminus coiled-coil domains present in PC-1 or PC-2. In summary, we show that PC-1 regulates arterial contractility through the formation of an interdependent signaling complex with PC-2 in endothelial cells. Flow stimulates PC-1/PC-2 clusters in the EC plasma membrane, leading to eNOS, IK channel and SK channel activation, vasodilation and a reduction in blood pressure.
    Keywords:  molecular biophysics; mouse; neuroscience; structural biology
    DOI:  https://doi.org/10.7554/eLife.74765
  15. Cell Signal. 2022 Feb 23. pii: S0898-6568(22)00054-7. [Epub ahead of print] 110294
       BACKGROUND AND AIMS: Inflammatory bowel diseases (IBD) result in chronic inflammation of the gastrointestinal tract. Genetic studies have shown that the GPR65 gene, as well as its missense coding variant, GPR65*Ile231Leu, is associated with IBD. We aimed to define the signalling and biological pathways downstream of GPR65 activation and evaluate the impact of GPR65*231Leu on these.
    METHODS: We used HEK 293 cells stably expressing GPR65 and deficient for either Gαs, Gαq/11 or Gα12/13, to define GPR65 signalling pathways, IBD patient biopsies and a panel of human tissues, primary immune cells and cell lines to determine biologic context, and genetic modulation of human THP-1-derived macrophages to examine the impact of GPR65 in bacterial phagocytosis and NLRP3 inflammasome activation.
    RESULTS: We confirmed that GPR65 signals via the Gαs pathway, leading to cAMP accumulation. GPR65 can also signal via the Gα12/13 pathway leading to formation of stress fibers, actin remodeling and RhoA activation; all impaired by the IBD-associated GPR65*231Leu allele. Gene expression profiling revealed greater expression of GPR65 in biopsies from inflamed compared to non-inflamed tissues from IBD patients or control individuals, potentially explained by infiltration of inflammatory immune cells. Decreased GPR65 expression in THP-1-derived macrophages leads to impaired bacterial phagocytosis, increased NLRP3 inflammasome activation and IL-1β secretion in response to an inflammatory stimulus.
    CONCLUSIONS: We demonstrate that GPR65 exerts its effects through Gαs- and Gα12/13-mediated pathways, that the IBD-associated GPR65*231Leu allele has compromised interactions with Gα12/13 and that KD of GPR65 leads to impaired bacterial phagocytosis and increased inflammatory signalling via the NLRP3 inflammasome. This work identifies a target for development of small molecule therapies.
    Keywords:  Actin remodeling; Bacterial phagocytosis; G proteins; GPR65; NLRP3 inflammasome
    DOI:  https://doi.org/10.1016/j.cellsig.2022.110294
  16. Indian J Pediatr. 2022 Mar 03.
       OBJECTIVES: To determine the demographic, clinical, and genetic profile of Turkish Caucasian PCD cases.
    METHODS: Targeted next-generation sequencing (t-NGS) of 46 nuclear genes was performed in 21 unrelated PCD cases. Sanger sequencing confirmed of potentially disease-related variations, and genotype-phenotype correlations were evaluated.
    RESULTS: Disease-related variations were identified in eight different genes (CCDC39, CCDC40, CCDC151, DNAAF2, DNAAF4, DNAH11, HYDIN, RSPH4A) in 52.4% (11/21) of the cases. The frequency of variations for CCDC151, DNAH11, and DNAAF2 genes which were highly mutated genes in the cohort was 18% in 11 patients. Each of the remaining gene variations was detected once (9%) in different patients. The variants, p.R482fs*12 in CCDC151, p.E216* in DNAAF2, p.I317* in DNAAF4, p.L318P and p.R1865* in DNAH11, and p.N1505D and p.L1167P in HYDIN gene were identified as novel variations. Interestingly, varying phenotypic findings were identified even in patients with the same mutation, which once again confirmed that PCD has a high phenotypic heterogeneity and shows individual differences.
    CONCLUSION: This t-NGS panel is potentially helpful for exact and rapid identification of reported/novel PCD-disease-causing variants to establish the molecular diagnosis of ciliary diseases.
    Keywords:  Ciliary diseases; Mutation analysis; Primary ciliary dyskinesia; Targeted next-generation sequencing
    DOI:  https://doi.org/10.1007/s12098-022-04098-z
  17. Front Cell Dev Biol. 2022 ;10 809425
      G protein-coupled receptors (GPCRs), as the largest family of receptors in the human body, are involved in the pathological mechanisms of many diseases. Heterotrimeric G proteins represent the main molecular switch and receive cell surface signals from activated GPCRs. Growing evidence suggests that Gα12 subfamily (Gα12/13)-mediated signaling plays a crucial role in cellular function and various pathological processes. The current research on the physiological and pathological function of Gα12/13 is constantly expanding, Changes in the expression levels of Gα12/13 have been found in a wide range of human diseases. However, the mechanistic research on Gα12/13 is scattered. This review briefly describes the structural sequences of the Gα12/13 isoforms and introduces the coupling of GPCRs and non-GPCRs to Gα12/13. The effects of Gα12/13 on RhoA and other signaling pathways and their roles in cell proliferation, migration, and immune cell function, are discussed. Finally, we focus on the pathological impacts of Gα12/13 in cancer, inflammation, metabolic diseases, fibrotic diseases, and circulatory disorders are brought to focus.
    Keywords:  G protein-coupled receptor; Gα12; Gα13; cell pathophysiology; diseases
    DOI:  https://doi.org/10.3389/fcell.2022.809425