scholarly journals Pancreatic Differentiation of Stem Cells Reveals Pathogenesis of a Syndrome of Ketosis-Prone Diabetes

Author(s):  
Diane Yang ◽  
Sanjeet Patel ◽  
Wojciech J. Szlachcic ◽  
Jolanta Chmielowiec ◽  
Diane Scaduto ◽  
...  

Genetic analysis of an adult patient with an unusual course of Ketosis-Prone Diabetes (KPD) and lacking islet autoantibodies demonstrated a nucleotide variant in the<i> </i>5’-UTR of <i>PDX1</i>, a beta-cell development gene. When differentiated to the pancreatic lineage, his induced pluripotent stem cells stalled at the definitive endoderm stage. Metabolomic analysis of the cells revealed that this was associated with leucine hypersensitivity during transition from the definitive endoderm to the pancreatic progenitor stage, and RNA-sequencing showed defects in leucine-sensitive mTOR pathways contribute to the differentiation deficiency. CRISPR-Cas9 manipulation of the <i>PDX1</i> variant demonstrated that it is necessary and sufficient to confer leucine sensitivity and the differentiation block, likely due to disruption of binding of the transcriptional regulator NFY to the <i>PDX1</i> 5’-UTR, leading to decreased PDX1 expression at the early pancreatic progenitor stage. Thus, the combination of an underlying defect in leucine catabolism characteristic of KPD with a functionally relevant heterozygous variant in a critical beta-cell gene that confers increased leucine sensitivity and inhibits endocrine cell differentiation resulted in the phenotype of late-onset beta-cell failure in this patient. We define the molecular pathogenesis of a diabetes syndrome and demonstrate the power of multi-omics analysis of patient-specific stem cells for clinical discovery.

2021 ◽  
Author(s):  
Diane Yang ◽  
Sanjeet Patel ◽  
Wojciech J. Szlachcic ◽  
Jolanta Chmielowiec ◽  
Diane Scaduto ◽  
...  

Genetic analysis of an adult patient with an unusual course of Ketosis-Prone Diabetes (KPD) and lacking islet autoantibodies demonstrated a nucleotide variant in the<i> </i>5’-UTR of <i>PDX1</i>, a beta-cell development gene. When differentiated to the pancreatic lineage, his induced pluripotent stem cells stalled at the definitive endoderm stage. Metabolomic analysis of the cells revealed that this was associated with leucine hypersensitivity during transition from the definitive endoderm to the pancreatic progenitor stage, and RNA-sequencing showed defects in leucine-sensitive mTOR pathways contribute to the differentiation deficiency. CRISPR-Cas9 manipulation of the <i>PDX1</i> variant demonstrated that it is necessary and sufficient to confer leucine sensitivity and the differentiation block, likely due to disruption of binding of the transcriptional regulator NFY to the <i>PDX1</i> 5’-UTR, leading to decreased PDX1 expression at the early pancreatic progenitor stage. Thus, the combination of an underlying defect in leucine catabolism characteristic of KPD with a functionally relevant heterozygous variant in a critical beta-cell gene that confers increased leucine sensitivity and inhibits endocrine cell differentiation resulted in the phenotype of late-onset beta-cell failure in this patient. We define the molecular pathogenesis of a diabetes syndrome and demonstrate the power of multi-omics analysis of patient-specific stem cells for clinical discovery.


2020 ◽  
Vol 15 (3) ◽  
pp. 187-201 ◽  
Author(s):  
Sunil K. Dubey ◽  
Amit Alexander ◽  
Munnangi Sivaram ◽  
Mukta Agrawal ◽  
Gautam Singhvi ◽  
...  

Damaged or disabled tissue is life-threatening due to the lack of proper treatment. Many conventional transplantation methods like autograft, iso-graft and allograft are in existence for ages, but they are not sufficient to treat all types of tissue or organ damages. Stem cells, with their unique capabilities like self-renewal and differentiate into various cell types, can be a potential strategy for tissue regeneration. However, the challenges like reproducibility, uncontrolled propagation and differentiation, isolation of specific kinds of cell and tumorigenic nature made these stem cells away from clinical application. Today, various types of stem cells like embryonic, fetal or gestational tissue, mesenchymal and induced-pluripotent stem cells are under investigation for their clinical application. Tissue engineering helps in configuring the stem cells to develop into a desired viable tissue, to use them clinically as a substitute for the conventional method. The use of stem cell-derived Extracellular Vesicles (EVs) is being studied to replace the stem cells, which decreases the immunological complications associated with the direct administration of stem cells. Tissue engineering also investigates various biomaterials to use clinically, either to replace the bones or as a scaffold to support the growth of stemcells/ tissue. Depending upon the need, there are various biomaterials like bio-ceramics, natural and synthetic biodegradable polymers to support replacement or regeneration of tissue. Like the other fields of science, tissue engineering is also incorporating the nanotechnology to develop nano-scaffolds to provide and support the growth of stem cells with an environment mimicking the Extracellular matrix (ECM) of the desired tissue. Tissue engineering is also used in the modulation of the immune system by using patient-specific Mesenchymal Stem Cells (MSCs) and by modifying the physical features of scaffolds that may provoke the immune system. This review describes the use of various stem cells, biomaterials and the impact of nanotechnology in regenerative medicine.


2021 ◽  
Vol 7 (12) ◽  
pp. eabf7412
Author(s):  
P. Nayak ◽  
A. Colas ◽  
M. Mercola ◽  
S. Varghese ◽  
S. Subramaniam

Understanding the mechanisms of myogenesis in human induced pluripotent stem cells (hiPSCs) is a prerequisite to achieving patient-specific therapy for diseases of skeletal muscle. hiPSCs of different origin show distinctive kinetics and ability to differentiate into myocytes. To address the unique cellular and temporal context of hiPSC differentiation, we perform a longitudinal comparison of the transcriptomic profiles of three hiPSC lines that display differential myogenic specification, one robust and two blunted. We detail temporal differences in mechanisms that lead to robust myogenic specification. We show gene expression signatures of putative cell subpopulations and extracellular matrix components that may support myogenesis. Furthermore, we show that targeted knockdown of ZIC3 at the outset of differentiation leads to improved myogenic specification in blunted hiPSC lines. Our study suggests that β-catenin transcriptional cofactors mediate cross-talk between multiple cellular processes and exogenous cues to facilitate specification of hiPSCs to mesoderm lineage, leading to robust myogenesis.


2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Thekkeparambil Chandrabose Srijaya ◽  
Padmaja Jayaprasad Pradeep ◽  
Rosnah Binti Zain ◽  
Sabri Musa ◽  
Noor Hayaty Abu Kasim ◽  
...  

Induced pluripotent stem cell-based therapy for treating genetic disorders has become an interesting field of research in recent years. However, there is a paucity of information regarding the applicability of induced pluripotent stem cells in dental research. Recent advances in the use of induced pluripotent stem cells have the potential for developing disease-specific iPSC linesin vitrofrom patients. Indeed, this has provided a perfect cell source for disease modeling and a better understanding of genetic aberrations, pathogenicity, and drug screening. In this paper, we will summarize the recent progress of the disease-specific iPSC development for various human diseases and try to evaluate the possibility of application of iPS technology in dentistry, including its capacity for reprogramming some genetic orodental diseases. In addition to the easy availability and suitability of dental stem cells, the approach of generating patient-specific pluripotent stem cells will undoubtedly benefit patients suffering from orodental disorders.


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