Branching morphogenesis as a driver of renal development

Mutations in PKD1 cause autosomal dominant polycystic kidney disease (ADPKD), a common genetic disease in which cysts form from kidney tubules. The predicted product of this gene is a novel protein with cell-adhesive and membrane-spanning domains. To test the hypothesis that polycystin, the product of the PKD1 gene, is a cell adhesion molecule, we raised antibodies against peptides derived from the unduplicated, membrane-spanning portion of the predicted amino acid sequence. These antibodies recognized membrane-associated polypeptides of 485 and 245 kDa in human fetal kidney homogenates. Expression was greater in fetal than adult kidney by both Western blot analysis and immunofluorescence. In fetal kidney, polycystin was localized to the plasma membranes of ureteric bud and comma and S-shaped bodies. However, in more mature tubules in fetal kidney, in adult kidney, and in polycystic kidney, the majority of polycystin staining was intracellular. The temporal and spatial regulation of polycystin expression during renal development lead us to speculate that polycystin may play a role in nephrogenesis.

Download Full-text

Epigallocatechin-3-Gallate Protects Pro-Acinar Epithelia Against Salivary Gland Radiation Injury

International Journal of Molecular Sciences ◽

10.3390/ijms22063162 ◽

2021 ◽

Vol 22 (6) ◽

pp. 3162

Author(s):

Erni Sulistiyani ◽

James M. Brimson ◽

Ajjima Chansaenroj ◽

Ladawan Sariya ◽

Ganokon Urkasemsin ◽

...

Keyword(s):

Salivary Gland ◽

Ex Vivo ◽

Biological Effects ◽

Branching Morphogenesis ◽

Epithelial Proliferation ◽

Expression Arrays ◽

Gene Expression Arrays ◽

Antioxidant Agents ◽

Bright Field Microscopy ◽

Injury Models

Antioxidant agents are promising pharmaceuticals to prevent salivary gland (SG) epithelial injury from radiotherapy and their associated irreversible dry mouth symptoms. Epigallocatechin-3-gallate (EGCG) is a well-known antioxidant that can exert growth or inhibitory biological effects in normal or pathological tissues leading to disease prevention. The effects of EGCG in the various SG epithelial compartments are poorly understood during homeostasis and upon radiation (IR) injury. This study aims to: (1) determine whether EGCG can support epithelial proliferation during homeostasis; and (2) investigate what epithelial cells are protected by EGCG from IR injury. Ex vivo mouse SG were treated with EGCG from 7.5–30 µg/mL for up to 72 h. Next, SG epithelial branching morphogenesis was evaluated by bright-field microscopy, immunofluorescence, and gene expression arrays. To establish IR injury models, linear accelerator (LINAC) technologies were utilized, and radiation doses optimized. EGCG epithelial effects in these injury models were assessed using light, confocal and electron microscopy, the Griess assay, immunohistochemistry, and gene arrays. SG pretreated with EGCG 7.5 µg/mL promoted epithelial proliferation and the development of pro-acinar buds and ducts in regular homeostasis. Furthermore, EGCG increased the populations of epithelial progenitors in buds and ducts and pro-acinar cells, most probably due to its observed antioxidant activity after IR injury, which prevented epithelial apoptosis. Future studies will assess the potential for nanocarriers to increase the oral bioavailability of EGCG.

Download Full-text

Erratum to “Regulatory Mechanisms of Branching Morphogenesis in Mouse Submandibular Gland Rudiments” [Jpn Dent Sci Rev. (54/1) (2018) 2–7]

Japanese Dental Science Review ◽

10.1016/j.jdsr.2020.11.002 ◽

2020 ◽

Author(s):

Masanori Kashimata ◽

Toru Hayashi

Keyword(s):

Submandibular Gland ◽

Branching Morphogenesis ◽

Regulatory Mechanisms

Download Full-text

Mechanical plasticity of collagen directs branch elongation in human mammary gland organoids

Nature Communications ◽

10.1038/s41467-021-22988-2 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

B. Buchmann ◽

L. K. Engelbrecht ◽

P. Fernandez ◽

F. P. Hutterer ◽

M. K. Raich ◽

...

Keyword(s):

Mechanical Response ◽

Developmental Process ◽

Branching Morphogenesis ◽

Collagen Network ◽

Mechanical Tension ◽

Structural Reorganization ◽

Linear Response Regime ◽

Human Mammary Gland ◽

The Matrix ◽

Tension Generation

AbstractEpithelial branch elongation is a central developmental process during branching morphogenesis in diverse organs. This fundamental growth process into large arborized epithelial networks is accompanied by structural reorganization of the surrounding extracellular matrix (ECM), well beyond its mechanical linear response regime. Here, we report that epithelial ductal elongation within human mammary organoid branches relies on the non-linear and plastic mechanical response of the surrounding collagen. Specifically, we demonstrate that collective back-and-forth motion of cells within the branches generates tension that is strong enough to induce a plastic reorganization of the surrounding collagen network which results in the formation of mechanically stable collagen cages. Such matrix encasing in turn directs further tension generation, branch outgrowth and plastic deformation of the matrix. The identified mechanical tension equilibrium sets a framework to understand how mechanical cues can direct ductal branch elongation.

Download Full-text

Effects of Environmental Conditions on Nephron Number: Modeling Maternal Disease and Epigenetic Regulation in Renal Development

International Journal of Molecular Sciences ◽

10.3390/ijms22084157 ◽

2021 ◽

Vol 22 (8) ◽

pp. 4157

Author(s):

Lars Fuhrmann ◽

Saskia Lindner ◽

Alexander-Thomas Hauser ◽

Clemens Höse ◽

Oliver Kretz ◽

...

Keyword(s):

Environmental Conditions ◽

High Glucose ◽

Culture Conditions ◽

Renal Development ◽

Organ Cultures ◽

Renal Growth ◽

Epigenetic Modifiers ◽

Metabolic Conditions ◽

Renal Size ◽

Maternal Disease

A growing body of evidence suggests that low nephron numbers at birth can increase the risk of chronic kidney disease or hypertension later in life. Environmental stressors, such as maternal malnutrition, medication and smoking, can influence renal size at birth. Using metanephric organ cultures to model single-variable environmental conditions, models of maternal disease were evaluated for patterns of developmental impairment. While hyperthermia had limited effects on renal development, fetal iron deficiency was associated with severe impairment of renal growth and nephrogenesis with an all-proximal phenotype. Culturing kidney explants under high glucose conditions led to cellular and transcriptomic changes resembling human diabetic nephropathy. Short-term high glucose culture conditions were sufficient for long-term alterations in DNA methylation-associated epigenetic memory. Finally, the role of epigenetic modifiers in renal development was tested using a small compound library. Among the selected epigenetic inhibitors, various compounds elicited an effect on renal growth, such as HDAC (entinostat, TH39), histone demethylase (deferasirox, deferoxamine) and histone methyltransferase (cyproheptadine) inhibitors. Thus, metanephric organ cultures provide a valuable system for studying metabolic conditions and a tool for screening for epigenetic modifiers in renal development.

Download Full-text

In vitro models of fetal lung development to enhance research into congenital lung diseases

Pediatric Surgery International ◽

10.1007/s00383-021-04864-8 ◽

2021 ◽

Author(s):

Soichi Shibuya ◽

Jessica Allen-Hyttinen ◽

Paolo De Coppi ◽

Federica Michielin

Keyword(s):

Lung Development ◽

Lung Diseases ◽

Ex Vivo ◽

Fetal Lung ◽

Branching Morphogenesis ◽

In Vitro Models ◽

Normal Lung ◽

Novel Therapeutic Strategies ◽

Pseudoglandular Stage

Abstract Purpose This paper aims to build upon previous work to definitively establish in vitro models of murine pseudoglandular stage lung development. These can be easily translated to human fetal lung samples to allow the investigation of lung development in physiologic and pathologic conditions. Methods Lungs were harvested from mouse embryos at E12.5 and cultured in three different settings, i.e., whole lung culture, mesenchyme-free epithelium culture, and organoid culture. For the whole lung culture, extracted lungs were embedded in Matrigel and incubated on permeable filters. Separately, distal epithelial tips were isolated by firstly removing mesothelial and mesenchymal cells, and then severing the tips from the airway tubes. These were then cultured either in branch-promoting or self-renewing conditions. Results Cultured whole lungs underwent branching morphogenesis similarly to native lungs. Real-time qPCR analysis demonstrated expression of key genes essential for lung bud formation. The culture condition for epithelial tips was optimized by testing different concentrations of FGF10 and CHIR99021 and evaluating branching formation. The epithelial rudiments in self-renewing conditions formed spherical 3D structures with homogeneous Sox9 expression. Conclusion We report efficient protocols for ex vivo culture systems of pseudoglandular stage mouse embryonic lungs. These models can be applied to human samples and could be useful to paediatric surgeons to investigate normal lung development, understand the pathogenesis of congenital lung diseases, and explore novel therapeutic strategies.

Download Full-text