This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Autosomal dominant polycystic kidney disease (ADPKD) is mainly caused by deficiency of polycystin-1 (PC1) or polycystin-2 (PC2). Altered autophagy has recently been implicated in ADPKD progression, but its exact regulation by PC1 and PC2 remains unclear. We therefore investigated cell death and survival during nutritional stress in mouse inner medullary collecting duct cells (mIMCDs), either wild-type (WT) or lacking PC1 (PC1KO) or PC2 (PC2KO), and human urine-derived proximal tubular epithelial cells (PTEC) from early-stage ADPKD patients with PC1 mutations versus healthy individuals. Basal autophagy was enhanced in PC1-deficient cells. Similarly, following starvation, autophagy was enhanced and cell death reduced when PC1 was reduced. Autophagy inhibition reduced cell death resistance in PC1KO mIMCDs to the WT level, implying that PC1 promotes autophagic cell survival. Although PC2 expression was increased in PC1KO mIMCDs, PC2 knockdown did not result in reduced autophagy. PC2KO mIMCDs displayed lower basal autophagy, but more autophagy and less cell death following chronic starvation. This could be reversed by overexpression of PC1 in PC2KO. Together, these findings indicate that PC1 levels are partially coupled to PC2 expression, and determine the transition from renal cell survival to death, leading to enhanced survival of ADPKD cells during nutritional stress.
Aneuploidy is generally considered harmful, but in some microorganisms, it can act as an adaptive mechanism against environmental stress. Here, we use Leishmania—a protozoan parasite with remarkable genome plasticity—to study the early steps of aneuploidy evolution under high drug pressure (using antimony or miltefosine as stressors). By combining single‐cell genomics, lineage tracing with cellular barcodes, and longitudinal genome characterization, we reveal that aneuploidy changes under antimony pressure result from polyclonal selection of pre‐existing karyotypes, complemented by further and rapid de novo alterations in chromosome copy number along evolution. In the case of miltefosine, early parasite adaptation is associated with independent point mutations in a miltefosine transporter gene, while aneuploidy changes only emerge later, upon exposure to increased drug levels. Therefore, polyclonality and genome plasticity are hallmarks of parasite adaptation, but the scenario of aneuploidy dynamics depends on the nature and strength of the environmental stress as well as on the existence of other pre‐adaptive mechanisms.
Aneuploidy is generally considered harmful, but in some microorganisms, it can act as an adaptive mechanism against environmental stresses. Here, we usedLeishmania-a protozoan parasite with a remarkable genome plasticity- to study the early evolution of aneuploidy under high drug pressure (antimony or miltefosine) as stressor model. By combining single-cell genomics, lineage tracing with cellular barcodes and longitudinal genome characterization, we revealed that antimony-induced aneuploidy changes result from the polyclonal selection of pre-existing karyotypes, complemented by further and rapid de novo alterations in chromosome copy number along evolution. In the case of miltefosine, early parasite adaptation was associated with independent pre-existing point mutations in a miltefosine transporter gene and aneuploidy changes only emerged later, upon exposure to increased concentration of the drug. Thus, polyclonality and genome plasticity are hallmarks of parasite adaptation, but the scenario of aneuploidy dynamics is dependent on the nature and strength of the environmental stress as well as on the existence of other pre-adaptive mechanisms.
Background and Aims Autosomal dominant polycystic kidney disease (ADPKD) is mainly caused by mutations in either PKD1 (ca. 78%) or PKD2 (ca. 15%), encoding for the proteins polycystin-1 (PC1) or polycystin-2 (PC2), respectively. Mutations in PKD1 generally lead to a more severe disease progression compared to PKD2 patients. The exact function of the polycystins in cyst formation remains unclear, but it is clear that the levels of PC1 and PC2 are inversely correlated to cyst formation. Moreover, renal stress has been proposed to enhance cystogenesis. We therefore aimed to investigate the cellular response towards nutritional stress in mouse inner medullary collecting duct cells (mIMCDs), either wild-type (WT) or lacking PC1 or PC2 (PC1KO or PC2KO), and unique human urine-derived proximal tubular epithelial cells (PTECs) of early-stage ADPKD patients with truncating PKD1 mutations versus healthy individuals, with a focus on cell survival (autophagy) and cell death. Method Cell death was assessed with Cytotox green-based live cell imaging in the Incucyte, by trypane blue exclusion and by analyzing the levels of cleaved Caspase 3. Autophagy was measured by LC3 immunoblotting and by counting GFP-LC3 punctae. Autophagy was blocked with Bafilomycin A1. To modulate the levels of PC1 and PC2, transient overexpression of human PC1 or siRNA-mediated knockdown of PC2 was performed. Results During chronic starvation, cell death was reduced and autophagy was increased in mouse PC1- and PC2-deficient mIMCDs. This was validated in human cells from early-stage ADPKD patients. Autophagy inhibition restored cell death resistance in KO cells, implying that decrease in cell death was caused by autophagy upregulation in PC1- and PC2KO cells. Interestingly, PC2 expression was increased in PC1KO cells, while PC2KO displayed a downregulation of PC1. Although PC2 is known to regulate autophagy, PC2 knockdown did not reduce autophagy in PC1KO cells, while the effect in PC2KO could be reversed by overexpression of PC1. Conclusion These findings indicate that PC1 levels determine the transition from renal cell survival to death, leading to enhanced survival of ADPKD cells during nutritional stress. Moreover, PC1 also indirectly influences this process by regulating PC1 levels during starvation. Our findings imply that in early stage ADPKD, cells with the lowest polycystin levels (which are most prone to form cysts) are more resistant to stress by autophagy upregulation. This is important, as renal stress is inherent to the cystic environment and has been proposed as an additional trigger in cystogenesis.
Background and Aims The correlation between genotype and phenotype is well described in ADPKD adults. PKD2 is milder than PKD1 disease, with end stage kidney disease (ESKD) occurring on average 20 years later, and patients with PKD1 truncating mutations having a more severe outcome than PKD1 non-truncating mutations. Still, large differences in outcome occur even within families carrying the same gene variation. Only a few cases series reported the genetic profile of severely affected ADPKD children and suggest an additional effect of hypomorphic genes. We therefore aim to analyse the geno-phenotype profile in a well characterized pediatric ADPKD cohort. Method Clinical, familial, biological and imaging data were collected longitudinally in children diagnosed with ADPKD. Genotypic analysis was done using a custom Agilent SureSelect gene panel containing 136 ciliopathy-associated genes, including PKD1 and PKD2. Mutations and/or variants identified were individually evaluated for pathogenicity. Results 57 ADPKD children from 44 families were diagnosed at a mean (± SD) age of 4.1 (±4.8) years. ADPKD diagnosis was made in 32 children (56%) because of asymptomatic screening as requested by the family; 7 (12%) due to presenting symptoms (6 due to urinary tract infection and 1 due to post-traumatic macroscopic hematuria); 9 (16%) due to a coincidental finding of renal cysts on US performed for another reason and in 9 cases (16%) a prenatal diagnosis was performed. Twenty-nine children (51%) met the definition of very-early onset (VEO) disease. We identified pathogenic mutations in 100% of our patients, in which the prevalence of PKD1 truncating, PKD1 non-truncating, PKD2 and GANAB mutations was 75%, 19%, 4%, and 2%, respectively. Four cases (7%) were due to a de novo mutation. Interestingly, in 29 patients (51%) the germline mutation was the only identified mutation. However, in the rest of the subjects additional variants were identified in other ciliopathy-associated genes. In 12 cases (21%) the additional identified variants found in either the PKD, PMM2, HNF1B, DNAJC1, CEP290, NEK1, MKKS, NPHP4 or PKHD1 genes were scored to have a potential phenotypic effect, which will be evaluated by continued follow-up of this cohort. Conclusion We report the first large cohort of genotyped ADPKD children, including an extensive panel of ciliopathy genes next to the PKD genes. Interestingly, we found a high prevalence of additional and potentially modifying variants in this young population.
Conclusions: Activation of immune response in macrophages involved in the development of ORG. Losing weight is beneficial to retard even reverse the progression of ORG.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.