Human iPSC-derived neural crest stem cells can produce EPO and induce erythropoiesis in anemic mice

Erythropoietin delivery through kidney organoids engineered with an episomal DNA vector

BACKGROUND

The kidney's endocrine function is essential for maintaining body homeostasis. Erythropoietin (EPO) is one of the key endocrine factors produced by the kidney, and kidney disease patients frequently experience anemia due to impaired EPO production. In the present study we explored the potential of human induced pluripotent stem cell (iPSC)-derived kidney organoids to restore EPO production.

METHODS

EPO secretion by kidney organoids was examined under 1% and 20% oxygen levels. To increase the EPO secreting capacity of kidney organoids, iPSC were genetically engineered with a non-integrating scaffold/matrix attachment region (S/MAR) DNA vector containing the EPO gene and generated EPO-overexpressing (EPO+) kidney organoids. To assess the physiological effects of EPO + organoids, 2-8 organoids were implanted subcutaneously in immunodeficient mice.

RESULTS

Kidney organoids produced low amounts of EPO under 1% oxygen. EPO S/MAR DNA vectors persisted and continued to robustly express EPO during iPSC expansion and kidney organoid differentiation without interfering with cellular proliferation. EPO + iPSC demonstrated efficient differentiation into kidney organoids. One-month post-implantation, EPO + organoids displayed continuously elevated EPO mRNA levels and significantly increased endothelial cell numbers compared to control organoids. Hematocrit levels were notably elevated in mice implanted with EPO + organoids in an organoid number-dependent manner. EPO + organoids furthermore influenced bone homeostasis in their hosts, evidenced by a change in trabecular bone composition.

CONCLUSION

Kidney organoids modified by EPO S/MAR DNA vector allow stable long-term delivery of EPO. The observed physiological effects following the implantation of EPO + organoids underscore the potential of gene-edited kidney organoids for endocrine restoration therapy.

Selective induction of human renal interstitial progenitor-like cell lineages from iPSCs reveals development of mesangial and EPO-producing cells

Recent regenerative studies using human pluripotent stem cells (hPSCs) have developed multiple kidney-lineage cells and organoids. However, to further form functional segments of the kidney, interactions of epithelial and interstitial cells are required. Here we describe a selective differentiation of renal interstitial progenitor-like cells (IPLCs) from human induced pluripotent stem cells (hiPSCs) by modifying our previous induction method for nephron progenitor cells (NPCs) and analyzing mouse embryonic interstitial progenitor cell (IPC) development. Our IPLCs combined with hiPSC-derived NPCs and nephric duct cells form nephrogenic niche- and mesangium-like structures in vitro. Furthermore, we successfully induce hiPSC-derived IPLCs to differentiate into mesangial and erythropoietin-producing cell lineages in vitro by screening differentiation-inducing factors and confirm that p38 MAPK, hypoxia, and VEGF signaling pathways are involved in the differentiation of mesangial-lineage cells. These findings indicate that our IPC-lineage induction method contributes to kidney regeneration and developmental research.

Role of dysfunctional peri-organ adipose tissue in metabolic disease

Metabolic disease is a complex disorder defined by a group with interrelated factors. There is growing evidence that obesity can lead to a variety of metabolic diseases, including diabetes and cardiovascular disease. Excessive adipose tissue (AT) deposition and ectopic accumulation can lead to increased peri-organ AT thickness. Dysregulation of peri-organ (perivascular, perirenal, and epicardial) AT is strongly associated with metabolic disease and its complications. The mechanisms include secretion of cytokines, activation of immunocytes, infiltration of inflammatory cells, involvement of stromal cells, and abnormal miRNA expression. This review discusses the associations and mechanisms by which various types of peri-organ AT affect metabolic diseases while addressing it as a potential future treatment strategy.

A protocol for the generation of EPO - Producing neural crest cells from human induced pluripotent stem cells

Insufficient production of erythropoietin (EPO) leads to anaemia. Developing methods for the generation and transplantation of EPO-producing cells would allow scientists to design personalised therapeutic solutions. Here we present a simple and highly reproducible protocol for the generation of neural crest cells (NCCs) that can produce and secrete erythropoiesis-competent EPO in response to hypoxia.

The role of hypoxia in stem cell regulation of the central nervous system: From embryonic development to adult proliferation

Hypoxia is involved in the regulation of various cell functions in the body, including the regulation of stem cells. The hypoxic microenvironment is indispensable from embryonic development to the regeneration and repair of adult cells. In addition to embryonic stem cells, which need to maintain their self-renewal properties and pluripotency in a hypoxic environment, adult stem cells, including neural stem cells (NSCs), also exist in a hypoxic microenvironment. The subventricular zone (SVZ) and hippocampal dentate gyrus (DG) are the main sites of adult neurogenesis in the brain. Hypoxia can promote the proliferation, migration, and maturation of NSCs in these regions. Also, because most neurons in the brain are non-regenerative, stem cell transplantation is considered as a promising strategy for treating central nervous system (CNS) diseases. Hypoxic treatment also increases the effectiveness of stem cell therapy. In this review, we firstly describe the role of hypoxia in different stem cells, such as embryonic stem cells, NSCs, and induced pluripotent stem cells, and discuss the role of hypoxia-treated stem cells in CNS diseases treatment. Furthermore, we highlight the role and mechanisms of hypoxia in regulating adult neurogenesis in the SVZ and DG and adult proliferation of other cells in the CNS.