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Flow-induced shear stress affects renal epithelial cells in the nephron tubule with potential implications for differential functionalities of the individual segments. Disruptions of cellular mechanosensation or flow conditions are associated with the development and progression of various renal diseases. This study investigates the effects of flow on the transcriptome of various renal tubular epithelial cell types. We analyzed the transcriptome of induced renal epithelial cells (iREC) cultured under physiological flow (0.57 ± 0.05 dyn/cm2 ) or in static conditions for 72 h. RNA sequencing showed 861 differentially expressed genes (DEGs), with 503 up- and 358 downregulated under flow. DEGs were linked to extracellular matrix (ECM) components (e.g. Col1a1, Col4a3, Col4a4, Fn1, Smoc2), junctions (Gja1, Tubb5), channel activities (Abcc4, Aqp1), and transcription factors (Foxq1, Lgr6). Next, we performed a meta-analysis comparing our data with three published datasets that subjected epithelial cell lines from distinct segments to flow, including proximal tubule and collecting duct cells. We found that TGF-ß, p53, MAPK, and PI3K are common flow-regulated pathways. Tfrc expression and thus the capability of iron uptake is commonly upregulated under flow. Many DEGs were related to kidney diseases, such as fibrosis (e.g. Tgfb1-3 and Serpine1). To obtain further mechanistic insights we investigated the role of the PI3K pathway in flow sensing. Applying flow and inhibition of PI3K showed significantly altered expression of transcripts related to ECM remodeling, angiogenesis, and ion transport. This suggests that the PI3K pathway is a critical mediator in flow-dependent cellular processes and gene expression, potentially influencing renal development and tissue remodeling. Finally, we derived a cross-cell-line summary of common as well as segment-specific transcriptomic effects, thus providing insights into the molecular mechanisms underlying flow sensing in the nephron tubule.
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Riñón , Fosfatidilinositol 3-Quinasas , Fosfatidilinositol 3-Quinasas/genética , Fosfatidilinositol 3-Quinasas/metabolismo , Riñón/metabolismo , Túbulos Renales Proximales/fisiología , Perfilación de la Expresión Génica , Células Epiteliales/metabolismoRESUMEN
SIGNIFICANCE STATEMENT: Mutations in hepatocyte nuclear factor-1 ß ( HNF1B ) are the most common monogenic causes of congenital renal malformations. HNF1B is necessary to directly reprogram fibroblasts to induced renal tubule epithelial cells (iRECs) and, as we demonstrate, can induce ectopic pronephric tissue in Xenopus ectodermal organoids. Using these two systems, we analyzed the effect of HNF1B mutations found in patients with cystic dysplastic kidney disease. We found cross-species conserved targets of HNF1B, identified transcripts that are differentially regulated by the patient-specific mutant protein, and functionally validated novel HNF1B targets in vivo . These results highlight evolutionarily conserved transcriptional mechanisms and provide insights into the genetic circuitry of nephrogenesis. BACKGROUND: Hepatocyte nuclear factor-1 ß (HNF1B) is an essential transcription factor during embryogenesis. Mutations in HNF1B are the most common monogenic causes of congenital cystic dysplastic renal malformations. The direct functional consequences of mutations in HNF1B on its transcriptional activity are unknown. METHODS: Direct reprogramming of mouse fibroblasts to induced renal tubular epithelial cells was conducted both with wild-type HNF1B and with patient mutations. HNF1B was expressed in Xenopus ectodermal explants. Transcriptomic analysis by bulk RNA-Seq identified conserved targets with differentially regulated expression by the wild-type or R295C mutant. CRISPR/Cas9 genome editing in Xenopus embryos evaluated transcriptional targets in vivo . RESULTS: HNF1B is essential for reprogramming mouse fibroblasts to induced renal tubular epithelial cells and induces development of ectopic renal organoids from pluripotent Xenopus cells. The mutation R295C retains reprogramming and inductive capacity but alters the expression of specific sets of downstream target genes instead of diminishing overall transcriptional activity of HNF1B. Surprisingly, targets associated with polycystic kidney disease were less affected than genes affected in congenital renal anomalies. Cross-species-conserved transcriptional targets were dysregulated in hnf1b CRISPR-depleted Xenopus embryos, confirming their dependence on hnf1b . CONCLUSIONS: HNF1B activates an evolutionarily conserved program of target genes that disease-causing mutations selectively disrupt. These findings provide insights into the renal transcriptional network that controls nephrogenesis.
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Factor Nuclear 1-beta del Hepatocito , Enfermedades Renales Quísticas , Animales , Ratones , Factor Nuclear 1-beta del Hepatocito/genética , Riñón/metabolismo , Enfermedades Renales Quísticas/genética , Mutación , Xenopus laevisRESUMEN
The kidney is a complex organ, and how it forms is a fascinating process. New technologies, such as single-cell transcriptomics, and enhanced imaging modalities are offering new approaches to understand the complex and intertwined processes during embryonic kidney development.
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Desarrollo Embrionario , Riñón , HumanosRESUMEN
Adverse effects of calcineurin inhibitors (CNI), such as hypertension, hyperkalemia, acidosis, hypomagnesemia and hypercalciuria, have been linked to dysfunction of the distal convoluted tubule (DCT). To test this, we generated a mouse model with an inducible DCT-specific deletion of the calcineurin regulatory subunit B alpha (CnB1-KO). Three weeks after CnB1 deletion, these mice exhibited hypomagnesemia and acidosis, but no hypertension, hyperkalemia or hypercalciuria. Consistent with the hypomagnesemia, CnB1-KO mice showed a downregulation of proteins implicated in DCT magnesium transport, including TRPM6, CNNM2, SLC41A3 and parvalbumin but expression of calcium channel TRPV5 in the kidney was unchanged. The abundance of the chloride/bicarbonate exchanger pendrin was increased, likely explaining the acidosis. Plasma aldosterone levels, kidney renin expression, abundance of phosphorylated sodium chloride-cotransporter and abundance of the epithelial sodium channel were similar in control and CnB1-KO mice, consistent with a normal sodium balance. Long-term potassium homeostasis was maintained in CnB1-KO mice, but in-vivo and ex-vivo experiments indicated that CnB1 contributes to acute regulation of potassium balance and sodium chloride-cotransporter. Tacrolimus treatment of control and CnB1-KO mice demonstrated that CNI-related hypomagnesemia is linked to impaired calcineurin-signaling in DCT, while hypocalciuria and hyponatremia occur independently of CnB1 in DCT. Transcriptome and proteome analyses of isolated DCTs demonstrated that CnB1 deletion impacts the expression of several DCT-specific proteins and signaling pathways. Thus, our data support a critical role of calcineurin for DCT function and provide novel insights into the pathophysiology of CNI side effects and involved molecular players in the DCT.
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Acidosis , Magnesio , Animales , Calcineurina/genética , Túbulos Renales Distales , Ratones , Proteoma/genética , TranscriptomaRESUMEN
OBJECTIVES: The purpose of this study was to construct fetal biometric charts between 16 and 40 weeks' gestation that were customized for parental characteristics, race, and parity, using quantile regression analysis. METHODS: In a multicenter cross-sectional study, 8070 sonographic examinations from low-risk pregnancies between 16 and 40 weeks' gestation were analyzed. The fetal measurements obtained were biparietal diameter, head circumference, abdominal circumference, and femur diaphysis length. Quantile regression was used to examine the impact of parental height and weight, parity, and race across biometric percentiles for the fetal measurements considered. RESULTS: Paternal and maternal height were significant covariates for all of the measurements considered (P < .05). Maternal weight significantly influenced head circumference, abdominal circumference, and femur diaphysis length. Parity was significantly associated with biparietal diameter and head circumference. Central African race was associated with head circumference and femur diaphysis length, whereas North African race was only associated with femur diaphysis length. CONCLUSIONS: In this study we constructed customized biometric growth charts using quantile regression in a large cohort of low-risk pregnancies. These charts offer the advantage of defining individualized normal ranges of fetal biometric parameters at each specific percentile corrected for parental height and weight, parity, and race. This study supports the importance of including these variables in routine sonographic screening for fetal growth abnormalities.
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Estatura/fisiología , Desarrollo Fetal/fisiología , Gráficos de Crecimiento , Padres , Grupos Raciales/estadística & datos numéricos , Ultrasonografía Prenatal/estadística & datos numéricos , Algoritmos , Simulación por Computador , Estudios Transversales , Femenino , Humanos , Interpretación de Imagen Asistida por Computador/métodos , Italia/epidemiología , Masculino , Modelos Estadísticos , Análisis de Regresión , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
BACKGROUND: Adherence to continuous positive air pressure (CPAP) in patients with obstructive sleep apnoea (OSA) has remained invariably low over the last decades. Remote monitoring of the nocturnal CPAP treatment, within telemedicine (TM)-based follow-up programs, in these patients has been suggested as a potential tool to improve adherence and release the workload of sleep units. The aim of this study was therefore to assess whether a follow-up program carried out by a Remote Medical Care Centre (RMCC), outside the sleep unit, improves adherence to CPAP in the short and long term in patients with OSA. METHODS: In this pilot protocol, we enrolled 37 patients starting CPAP in our Sleep Centre (SC). After three months of standard care in our SC, patients initiated a six-month remote follow-up carried out by the RMCC, functioning as an intermediary between patients and SC. Monthly reports and indication for face-to-face visits were sent to the SC for six months. After this period patients returned to usual care for one year. Results were compared with those obtained in 38 patients (controls) followed with usual care over the same time range. RESULTS: Mean nightly use of CPAP increased from 3.2 ± 2.4â h pre-RMCC to 5.2 ± 1.9â h post-RMCC (p < 0.0001). Nights/month of CPAP use improved from 19.8 ± 9.2 to 25.2 ± 2.5 (p < 0.05) and nights/month with CPAP use >4â h from 12.5 ± 10 to 21.03 ± 8.9 (p < 0.05). This improvement remained stable after 12 months from the return of patients to usual care. No significant changes in CPAP use were observed in controls over the time. CONCLUSION: A six-month follow-up through a remote facility can significantly improve adherence to CPAP in the short and long term. This pilot study provides a solid base for the design of multicentre randomized trials focusing on new models which are able to increase the long-term efficacy of TM programs.
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We used arrays of bioprinted renal epithelial cell spheroids for toxicity testing with cisplatin. The concentration-dependent cell death rate was determined using a lactate dehydrogenase assay. Bioprinted spheroids showed enhanced sensitivity to the treatment in comparison to monolayers of the same cell type. The measured dose-response curves revealed an inhibitory concentration of the spheroids of IC 50 = 9 ± 3 µM in contrast to the monolayers with IC 50 = 17 ± 2 µM. Fluorescent labeling of a nephrotoxicity biomarker, kidney injury molecule 1 indicated an accumulation of the molecule in the central lumen of the spheroids. Finally, we tested an approach for an automatic readout of toxicity based on microscopic images with deep learning. Therefore, we created a dataset comprising images of single spheroids, with corresponding labels of the determined cell death rates for training. The algorithm was able to distinguish between three classes of no, mild, and severe treatment effects with a balanced accuracy of 78.7%.
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Shoulder pain (SP) is a common clinical complaint among wheelchair basketball (WB) players, since their shoulders are exposed to intense overload and overhead movements. The supraspinatus tendon is the most exposed to WB-related injuries and it is primarily responsible for SP in WB athletes. In these cases, SP rehabilitation remains the main treatment, but there is still a lack of specific protocols which should be customized to WB players' peculiarities and to the supraspinatus muscle activity monitor, and the improvement of rehabilitation outcomes is slow. Thus, the aim of this study was to verify if the improvement of supraspinatus muscle activity, monitored in real time with surface electromyography (sEMG) during the execution of therapeutic exercises, could speed up SP rehabilitation outcomes in WB players. Thirty-three athletes were enrolled. They were divided into two groups. Both groups underwent the same shoulder rehabilitation program, but only the Exercise Plus sEMG Biofeedback Group executed therapeutic exercises while the activity of the supraspinatus muscles was monitored using sEMG. Participants were evaluated at enrollment (T0), at the end of 4 weeks of the rehabilitation program (T1), and 8 weeks after T1 (T2), using the following outcome measures: supraspinatus muscle activity as root mean square (RMS), Wheelchair User's Shoulder Pain Index (WUSPI), shoulder abduction, and external rotation range of motion (ROM). The Exercise Plus sEMG Biofeedback Group improved more and faster for all the outcomes compared to the Exercise Group. The monitoring and improvement of supraspinatus muscle activity seems to be an effective way to speed up SP rehabilitation outcomes in WB players, since it makes the performance of therapeutic exercise more precise and finalized, obtaining better and faster results in terms of recovery of shoulder function.
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Baloncesto , Silla de Ruedas , Humanos , Manguito de los Rotadores , Dolor de Hombro , Resultado del Tratamiento , Rango del Movimiento ArticularRESUMEN
Renal tubular cells frequently lose differentiation markers and physiological properties when propagated in conventional cell culture conditions. Embedding cells in 3D microenvironments or controlling their 3D assembly by bioprinting can enhance their physiological properties, which is beneficial for modeling diseases in vitro. A potential cellular source for modeling renal tubular physiology and kidney diseases in vitro are directly reprogrammed induced renal tubular epithelial cells (iRECs). iRECs were cultured in various biomaterials and as bioprinted tubular structures. They showed high compatibility with the embedding substrates and dispensing methods. The morphology of multicellular aggregates was substantially influenced by the 3D microenvironment. Transcriptomic analyses revealed signatures of differentially expressed genes specific to each of the selected biomaterials. Using a new cellular model for autosomal-dominant polycystic kidney disease, Pkd1-/- iRECs showed disrupted morphology in bioprinted tubules and a marked upregulation of the Aldehyde dehydrogenase 1a1 (Aldh1a1). In conclusion, 3D microenvironments strongly influence the morphology and expression profiles of iRECs, help to unmask disease phenotypes, and can be adapted to experimental demands. Combining a direct reprogramming approach with appropriate biomaterials will facilitate construction of biomimetic kidney tubules and disease models at the microscale.
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Biomimética , Enfermedades Renales Poliquísticas , Humanos , Riñón , Células Epiteliales , Materiales BiocompatiblesRESUMEN
Scalable fabrication concepts of 3D kidney tissue models are required to enable their application in pharmaceutical high-throughput screenings. Yet the reconstruction of complex tissue structures remains technologically challenging. We present a novel concept reducing the fabrication demands, by using controlled cellular self-assembly to achieve higher tissue complexities from significantly simplified construct designs. We used drop-on-demand bioprinting to fabricate locally confined patterns of renal epithelial cells embedded in a hydrogel matrix. These patterns provide defined local cell densities (cell count variance <11%) with high viability (92 ± 2%). Based on these patterns, controlled self-assembly leads to the formation of renal spheroids and nephron-like tubules with a predefined size and spatial localization. With this, we fabricated scalable arrays of hollow epithelial spheroids. The spheroid sizes correlated with the initial cell count per unit and could be stepwise adjusted, ranging from Ø = 84, 104, 120-131µm in diameter (size variance <9%). Furthermore, we fabricated scalable line-shaped patterns, which self-assembled to hollow cellular tubules (Ø = 105 ± 22µm). These showed a continuous lumen with prescribed orientation, lined by an epithelial monolayer with tight junctions. Additionally, upregulated expression of kidney-specific functional genes compared to 2D cell monolayers indicated increased tissue functionality, as revealed by mRNA sequencing. Furthermore, our concept enabled the fabrication of hybrid tubules, which consisted of arranged subsections of different cell types, combining murine and human epithelial cells. Finally, we integrated the self-assembled fabrication into a microfluidic chip and achieved fluidic access to the lumen at the terminal sites of the tubules. With this, we realized flow conditions with a wall shear stress of 0.05 ± 0.02 dyne cm-2driven by hydrostatic pressure for scalable dynamic culture towards a nephron-on-chip model.
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Bioimpresión , Animales , Recuento de Células , Células Epiteliales , Humanos , Riñón , Ratones , Nefronas , Esferoides CelularesRESUMEN
OBJECTIVE: To construct reference limits for gestation of umbilical vein blood flow (UVBF) in normal singleton pregnancies between 14 and 40 weeks of gestation using quantile regression. METHODS: We ultrasonographycally examined 852 fetuses from low-risk pregnancies between 16 and 40 weeks of gestation in a prospective cross-sectional study. UV diameter and time-averaged maximum velocity (TAMXV) were measured in UV intra-abdominal portion by real time and Doppler ultrasonography. A semi-automatic measurement software was used to obtain UV diameter values. UVBF was then calculated from UV diameter and TAMXV measurements and expressed both as absolute value and as value normalized for fetal abdominal circumference (UVBF/AC). Individual centile values of the variables investigated were established by quantile regression in the gestational interval considered. In 50 cases UVBF was measured twice by the same investigator or by a second investigator and the intra- and inter-observer agreement were calculated. RESULTS: A significant increase in UV diameter, TAMXV, UVBF absolute value and UVBF/AC was evidenced in the gestational period considered. Growth charts were established based on these measurements. The intra- and inter-observer intraclass correlation coefficients resulted as 0.92 (0.87-0.96) and 0.89 (0.84-0.97), respectively, for UBVF. CONCLUSIONS: In this study we constructed UVBF charts using quantile regression in a large cohort of low-risk pregnancies. These charts offer the advantage of specific estimated regression parameters for each percentile, better defining the normal range of UVBF. This promises to be useful in the diagnosis and management of fetuses with abnormal fetal growth.