Small Molecule-Induced Pancreatic β-Like Cell Development: Mechanistic Approaches and Available Strategies

A simple tool for the synchronous differentiation of human induced pluripotent stem cells into pancreatic progenitors

Efficient differentiation of human induced pluripotent stem cells (hiPSCs) into functional pancreatic cells holds great promise for diabetes research and treatment. However, a robust culture strategy for producing pancreatic progenitors with high homogeneity is lacking. Here, we established a simple differentiation strategy for generating synchronous iPSC-derived pancreatic progenitors via a two-step method of sequential cell synchronization using botulinum hemagglutinin (HA), an E-cadherin function-blocking agent. Of the various methods tested, the first-step synchronization method with HA exposure induces a synchronous switch from E- to N-cadherin and N- to E-cadherin expression by spatially controlling heterogeneous cell distribution, subsequently improving their competency for directed differentiation into definitive endodermal cells from iPSCs. The iPSC-derived definitive endodermal cells can efficiently generate PDX1+ and NKX6.1+ pancreatic progenitor cells in high yields. The PDX1+ and PDX1+ /NKX6.1+ cell densities showed 1.6- and 2.2-fold increases, respectively, compared with those from unsynchronized cultures. The intra-run and inter-run coefficient of variation were below 10%, indicating stable and robust differentiation across different cultures and runs. Our approach is a simple and efficient strategy to produce large quantities of differentiated cells with the highest homogeneity during multistage pancreatic progenitor differentiation, providing a potential tool for guided differentiation of iPSCs to functional insulin-producing cells.

iPSC-Derived Glioblastoma Cells Have Enhanced Stemness Wnt/β-Catenin Activity Which Is Negatively Regulated by Wnt Antagonist sFRP4

Growing evidence indicates that cancer stem cells (CSCs) endow the tumor with stem-like properties. Recently, induced pluripotent stem cells (iPSCs) have gained increased attention because of their easy derivation and availability and their potential to differentiate into any cell type. A CSC model derived from iPSCs of human origin would help understand the driving force of tumor initiation and early progression. We report the efficient generation of feeder-free SSEA4, TRA-1-60 and TRA-1-81 positive iPSCs from amniotic membrane-derived mesenchymal stem cells (AMMSCs), which successfully differentiated into three germ layers. We then developed human iPSC-derived glioblastoma multiforme (GBM) model using conditioned media (CM) from U87MG cell line and CSCs derived from U87MG, which confer iPSCs with GBM and GSC-like phenotypes within five days. Both cell types overexpress MGMT and GLI2, but only GSCs overexpress CD133, CD44, ABCG2 and ABCC2. We also observed overexpression of LEF1 and β-catenin in both cell types. Down-regulation of Wnt antagonist secreted frizzled-related protein 4 (sFRP4) in GBM and GSCs, indicating activation of the Wnt/β-catenin pathway, which could be involved in the conversion of iPSCs to CSCs. From future perspectives, our study will help in the creation of a rapid cell-based platform for understanding the complexity of GBM.

Recent trends and advances in type 1 diabetes therapeutics: A comprehensive review

Type 1 diabetes (T1D) is a chronic autoimmune disease characterized by the destruction of pancreatic β-cells, leading to insulin deficiency. Insulin replacement therapy is the current standard of care for T1D, but it has significant limitations. However, stem cell-based replacement therapy has the potential to restore β-cell function and achieve glycaemic control eradicating the necessity for drugs or injecting insulin externally. While significant progress has been made in preclinical studies, the clinical translation of stem cell therapy for T1D is still in its early stages. In continuation, further research is essentially required to determine the safety and efficacy of stem cell therapies and to develop strategies to prevent immune rejection of stem cell-derived β-cells. The current review highlights the current state of cellular therapies for T1D including, different types of stem cell therapies, gene therapy, immunotherapy, artificial pancreas, and cell encapsulation being investigated, and their potential for clinical translation.

In silico discovery of small molecules for efficient stem cell differentiation into definitive endoderm

Improving methods for human embryonic stem cell differentiation represents a challenge in modern regenerative medicine research. Using drug repurposing approaches, we discover small molecules that regulate the formation of definitive endoderm. Among them are inhibitors of known processes involved in endoderm differentiation (mTOR, PI3K, and JNK pathways) and a new compound, with an unknown mechanism of action, capable of inducing endoderm formation in the absence of growth factors in the media. Optimization of the classical protocol by inclusion of this compound achieves the same differentiation efficiency with a 90% cost reduction. The presented in silico procedure for candidate molecule selection has broad potential for improving stem cell differentiation protocols.

Manufacturing clinical-grade human induced pluripotent stem cell-derived beta cells for diabetes treatment

The unlimited proliferative capacity of human pluripotent stem cells (hPSCs) fortifies it as one of the most attractive sources for cell therapy application in diabetes. In the past two decades, vast research efforts have been invested in developing strategies to differentiate hPSCs into clinically suitable insulin‐producing endocrine cells or functional beta cells (β cells). With the end goal being clinical translation, it is critical for hPSCs and insulin‐producing β cells to be derived, handled, stored, maintained and expanded with clinical compliance. This review focuses on the key processes and guidelines for clinical translation of human induced pluripotent stem cell (hiPSC)‐derived β cells for diabetes cell therapy. Here, we discuss the (1) key considerations of manufacturing clinical‐grade hiPSCs, (2) scale‐up and differentiation of clinical‐grade hiPSCs into β cells in clinically compliant conditions and (3) mandatory quality control and product release criteria necessitated by various regulatory bodies to approve the use of the cell‐based products.

Gymnemic Acid Ameliorates Pancreatic β-Cell Dysfunction by Modulating Pdx1 Expression: A Possible Strategy for β-Cell Regeneration

BACKGROUND

Endogenous pancreatic β-cell regeneration is a promising therapeutic approach for enhancing β-cell function and neogenesis in diabetes. Various findings have reported that regeneration might occur via stimulating β-cell proliferation, neogenesis, or conversion from other pancreatic cells to β-like cells. Although the current scenario illustrates numerous therapeutic strategies and approaches that concern endogenous β-cell regeneration, all of them have not been successful to a greater extent because of cost effectiveness, availability of suitable donors and rejection in case of transplantation, or lack of scientific evidence for many phytochemicals derived from plants that have been employed in traditional medicine. Therefore, the present study aims to investigate the effect of gymnemic acid (GA) on β-cell regeneration in streptozotocin-induced type 1 diabetic rats and high glucose exposed RIN5-F cells.

METHODS

The study involves histopathological and immunohistochemical analysis to examine the islet's architecture. Quantitative polymerase chain reaction (qPCR) and/or immunoblot were employed to quantify the β-cell regeneration markers and cell cycle proliferative markers.

RESULTS

The immunoexpression of E-cadherin, β-catenin, and phosphoinositide 3-kinases/protein kinase B were significantly increased in GA-treated diabetic rats. On the other hand, treatment with GA upregulated the pancreatic regenerative transcription factor viz. pancreatic duodenal homeobox 1, Neurogenin 3, MafA, NeuroD1, and β-cells proliferative markers such as CDK4, and Cyclin D1, with a simultaneous downregulation of the forkhead box O, glycogen synthase kinase-3, and p21^cip1 in diabetic treated rats. Adding to this, we noticed increased nuclear localization of Pdx1 in GA treated high glucose exposed RIN5-F cells.

CONCLUSION

Our results suggested that GA acts as a potential therapeutic candidate for endogenous β-cell regeneration in treating type 1 diabetes.

Molecular study of the proliferation process of beta cells derived from pluripotent stem cells

BACKGROUND

Diabetes mellitus (DM) is a chronic metabolic disorder, increasing in the number of patients and poses a severe threat to human health. Significant advances have been made in DM treatment; the most important of which is differentiation and proliferation of beta cells from IPSCs.

METHODS

Data were collected from PUBMED at various time points up to the academic year of 2020. The related keywords are listed as follows: "Induced pluripotent stem cell", "Proliferation", "Growth factor", "Small molecule", "cardiotoxicity" and "Scaffold."

RESULT

The use of growth factors along with small molecules can be a good strategy for beta-cell proliferation. Also, proliferation of beta cells on nanofibers scaffolds can create a similar in vivo environment, that leads to increased function of beta-cell. Some transcription factors that cause beta cells proliferation play an important role in inflammation; so, it is essential to monitor them to prevent inflammation.

CONCLUSION

Finally, the simultaneous use of growth factors, micronutrients and scaffolds can be an excellent strategy to increase the proliferation and function of beta cells derived from IPSCs.

Therapeutic Status and Available Strategies in Pancreatic Ductal Adenocarcinoma

One of the most severe and devastating cancer is pancreatic cancer. Pancreatic ductal adenocarcinoma (PDAC) is one of the major pancreatic exocrine cancer with a poor prognosis and growing prevalence. It is the most deadly disease, with an overall five-year survival rate of 6% to 10%. According to various reports, it has been demonstrated that pancreatic cancer stem cells (PCSCs) are the main factor responsible for the tumor development, proliferation, resistance to anti-cancer drugs, and recurrence of tumors after surgery. PCSCs have encouraged new therapeutic methods to be explored that can specifically target cancer cells. Furthermore, stem cells, especially mesenchymal stem cells (MSCs), are known as influential anti-cancer agents as they function through anti-inflammatory, paracrine, cytokines, and chemokine's action. The properties of MSCs, such as migration to the site of infection and host immune cell activation by its secretome, seem to control the microenvironment of the pancreatic tumor. MSCs secretome exhibits similar therapeutic advantages as a conventional cell-based therapy. Moreover, the potential for drug delivery could be enhanced by engineered MSCs to increase drug bioactivity and absorption at the tumor site. In this review, we have discussed available therapeutic strategies, treatment hurdles, and the role of different factors such as PCSCs, cysteine, GPCR, PKM2, signaling pathways, immunotherapy, and NK-based therapy in pancreatic cancer.

Engineering-inspired approaches to study β-cell function and diabetes

Strategies to mitigate the pathologies from diabetes range from simply administering insulin to prescribing complex drug/biologic regimens combined with lifestyle changes. There is a substantial effort to better understand β-cell physiology during diabetes pathogenesis as a means to develop improved therapies. The convergence of multiple fields ranging from developmental biology to microfluidic engineering has led to the development of new experimental systems to better study complex aspects of diabetes and β-cell biology. Here we discuss the available insulin-secreting cell types used in research, ranging from primary human β-cells, to cell lines, to pluripotent stem cell-derived β-like cells. Each of these sources possess inherent strengths and weaknesses pertinent to specific applications, especially in the context of engineered platforms. We then outline how insulin-expressing cells have been used in engineered platforms and how recent advances allow for better mimicry of in vivo conditions. Chief among these conditions are β-cell interactions with other endocrine organs. This facet is beginning to be thoroughly addressed by the organ-on-a-chip community, but holds enormous potential in the development of novel diabetes therapeutics. Furthermore, high throughput strategies focused on studying β-cell biology, improving β-cell differentiation, or proliferation have led to enormous contributions in the field and will no doubt be instrumental in bringing new diabetes therapeutics to the clinic.

Insulin/Glucose-Responsive Cells Derived from Induced Pluripotent Stem Cells: Disease Modeling and Treatment of Diabetes

Type 2 diabetes, characterized by dysfunction of pancreatic β-cells and insulin resistance in peripheral organs, accounts for more than 90% of all diabetes. Despite current developments of new drugs and strategies to prevent/treat diabetes, there is no ideal therapy targeting all aspects of the disease. Restoration, however, of insulin-producing β-cells, as well as insulin-responsive cells, would be a logical strategy for the treatment of diabetes. In recent years, generation of transplantable cells derived from stem cells in vitro has emerged as an important research area. Pluripotent stem cells, either embryonic or induced, are alternative and feasible sources of insulin-secreting and glucose-responsive cells. This notwithstanding, consistent generation of robust glucose/insulin-responsive cells remains challenging. In this review, we describe basic concepts of the generation of induced pluripotent stem cells and subsequent differentiation of these into pancreatic β-like cells, myotubes, as well as adipocyte- and hepatocyte-like cells. Use of these for modeling of human disease is now feasible, while development of replacement therapies requires continued efforts.