Biology subjects

Ko, Y.-G.

Publications and source records attributed to Ko, Y.-G..

5 recordsLinked to original sources

bioRxiv2026

Human iPSCs and iPSC-Derived Endothelial Cells from PAD Patients and Healthy Donors Exhibit Comparable Characteristics and Potency: Implications for Autologous Cell Therapy in Peripheral Artery Disease

BACKGROUND: Peripheral artery disease (PAD) can lead to amputation in advanced cases, making cell therapy using human induced pluripotent stem cells (hiPSCs) a promising therapeutic option. hiPSC-derived endothelial cells (hiPSC-ECs) have shown favorable effects in treating experimental ischemic cardiovascular disease. An autologous approach for PAD patients is preferable to avoid immunological reactions. However, it is yet unknown whether hiPSCs and hiPSC-ECs derived from PAD patients have similar characteristics and potency compared to those derived from non-PAD donors. Therefore, we explored whether there are significant differences in the characteristics and potency of hiPSCs and hiPSC-ECs between non-PAD donors and PAD patients. METHODS: We generated hiPSCs from the blood of non-PAD donors and patients with PAD. We determined the pluripotency of hiPSCs using qRT-PCR, flow cytometry, immunostaining, RNA-seq, and teratoma formation assay. The genetic stability of hiPSCs was confirmed by G-banding karyotyping. We then differentiated hiPSCs into endothelial cells (ECs) in a clinically compatible manner. We compared the characteristics and therapeutic potency of hiPSC-ECs derived from non-PAD and PAD groups using qRT-PCR, flow cytometry, immunostaining, and RNA-seq. In vitro endothelial functions were determined by nitric oxide (NO) production and capillary network formation. Therapeutic potency and incorporation of engrafted hiPSC-ECs were evaluated in a hindlimb ischemia model. RESULTS: We successfully generated hiPSCs from the blood of seven non-PAD donors and eight PAD patients. Both non-PAD and PAD-derived hiPSCs exhibited similar expression levels of pluripotency markers. All hiPSCs, regardless of the group, formed teratomas and showed normal karyotypes. RNA-seq analyses revealed similar gene expression profiles between the groups. hiPSC-ECs derived from both non-PAD and PAD donors exhibited similar expression levels of EC markers at both the gene and protein levels. RNA-seq analyses showed no significant overall differences in gene expression profiles between the groups. Functional analyses demonstrated similar endothelial characteristics and function in hiPSC-ECs from both groups. Both groups showed similar perfusion recovery, limb salvage, and vessel-forming capacity. Engrafted hiPSC-ECs from both groups also exhibited similar angiogenic and vessel-forming capabilities. CONCLUSIONS: Our study demonstrated no significant differences in hiPSCs and hiPSC-ECs derived from non-PAD donors and PAD patients in terms of molecular and cell biological characteristics, therapeutic effects, and vessel-forming capability. Our study indicates that hiPSCs and hiPSC-ECs derived from PAD patients can serve as a novel platform for autologous cell therapy.

cell biology↗

bioRxiv2022

Stress-relief function of migrasomal autophagosomeformed by inhibition of autophagosome/lysosome fusion

Glioblastoma (GBM) is more difficult to treat than other intractable adult tumors. Here, we describe the composition and function of migrasomes generated along with GBM cell migration. Proteomic analysis revealed that LC3B-positive autophagosomes were abundant in the migrasomes of GBM cells. An increased number of migrasomes was observed following treatment with chloroquine (CQ) or inhibition of the expression of STX17 and SNAP29, which are involved in autophagosome/lysosome fusion. Although ATG7 ablation, which is involved in LC3B lipidation, did not suppress migrasome formation, it was confirmed that migrasome formation could be diminished by blocking the alternative autophagy pathway through double knockout of ATG7/BECN1. Furthermore, depletion of ITGA5 or TSPAN4 did not relieve endoplasmic reticulum (ER) stress in cells, resulting in cell death. Taken together, our study suggests that increasing the number of autophagosomes, through inhibition of autophagosome/lysosome fusion, generates migrasomes that have the capacity to alleviate cellular stress. Summary statementThis study demonstrates that glioblastoma cells contain autophagosomes within their migrasomes. Under stress conditions, the formation of migrasomes serves as a stress-relief mechanism to alleviate cell death.

cell biology↗

bioRxiv2022

Central role of Prominin-1 in lipid rafts during liver regeneration

Prominin-1 (PROM1), a lipid raft protein, is required for maintaining cancer stem cell properties in hepatocarcinoma cell lines, but its physiological roles in the liver have not been well studied. Here, we investigated the role of PROM1 in lipid rafts with a precise molecular mechanism during liver regeneration. We found that the expression of PROM1 increased during liver regeneration after 2/3 partial hepatectomy (PHx) or CCl4 injection. Interestingly, hepatocyte proliferation and liver regeneration were attenuated in liver-specific Prom1 knockout (Prom1LKO) mice compared to wild-type (Prom1f/f) mice. Detailed mechanistic studies revealed that PROM1 interacted with the interleukin-6 signal transducer glycoprotein 130 (GP130) and confined GP130 to lipid rafts so that STAT3 signaling by IL-6 was effectively activated. Moreover, the overexpression of the glycosylphosphatidylinsositol (GPI)-anchored first extracellular domain of PROM1 (PROM1GPI-EX1), which is a domain that binds to GP130, rescued the proliferation of hepatocytes and liver regeneration in Prom1LKO mice. PROM1 is upregulated in hepatocytes during liver regeneration, and upregulated PROM1 recruits GP130 into lipid rafts and activates the IL6-GP130-STAT3 axis. Thus, we conclude that PROM1 plays an important role in lipid rafts during liver regeneration and might be a promising target for therapeutic applications of liver transplantation.

cell biology↗

bioRxiv2019

Hepatocytic Prominin-1 protects liver fibrosis by stabilizing the SMAD7 protein

Background and AimsProminin-1 (PROM1) is known to be upregulated in hepatocytic progenitor cells (HPCs) and cholangiocytes of fibrotic livers. To understand the function of upregulated PROM1 during liver fibrosis, we analyzed liver fibrosis from global and liver-specific Prom1 knockout mice and investigated the molecular mechanism of how Prom1 protects the liver against liver fibrosis. MethodsWe analyzed PROM1 expression from human liver with mild and severe liver fibrosis (n=4-9). Liver fibrosis was induced by carbon tetrachloride (CCl4) treatment and bile duct ligation (BDL) from wild type and global and liver-specific knockout mice (n=3-13). The severity of liver fibrosis was determined by qRT-PCR, immunostaining and immunoblotting for fibrotic markers such as SMA, collagen. TGF{beta} signaling was also analyzed from fibrotic liver and primary hepatocytes of wild type and global and liver-specific knockout mice (n=3-5). Molecular interaction between PROM1 and SMAD7 was determined by endogenous and exogenous co-immunoprecipitation. ResultsPROM1 was found in the plasma membranes of both healthy and fibrotic hepatocytes and cholangiocytes. Global Prom1 knockout aggravated BDL- and CCl4-induced liver fibrosis. Prom1-/- hepatocytes showed increased TGF{beta} signaling due to reduced SMAD7 protein expression compared to that in wild-type hepatocytes. PROM1 prevented SMURF2-induced SMAD7 ubiquitination and degradation by interfering with the molecular association of SMAD7 with SMURF2. We also demonstrated that liver-specific Prom 1 knockout aggravated BDL-induced liver fibrosis due to reduced levels of SMAD7. ConclusionHepatocytic PROM1 stabilizes SMAD7, preventing TGF{beta} signaling. Thus, PROM1 is necessary for the negative regulation of TGF{beta} signaling during liver fibrosis.

cell biology↗

bioRxiv2019

Prominin-1-Radixin Axis controls hepatic gluconeogenesis by regulating PKA activity

Prominin-1 (Prom1) is a major cell surface marker of cancer stem cells, but its physiological functions in the liver have not been elucidated. We analyzed the levels of mRNA transcripts in serum-starved primary Prom1+/+ and Prom1-/- mouse hepatocytes using RNA-sequencing (RNA-seq) data, and found that CREB target genes were down-regulated. This initial observation led us to determine that the Prom1 deficiency inhibited cAMP response element binding protein (CREB) activation and gluconeogenesis, but not cyclic AMP (cAMP) accumulation, in glucagon-, epinephrine-, or forskolin-treated liver tissues and primary hepatocytes, and mitigated glucagon-induced hyperglycemia. Because Prom1 interacted with radixin, the Prom1 deficiency prevented radixin from localizing to the plasma membrane. Moreover, systemic adenoviral knockdown of radixin inhibited CREB activation and gluconeogenesis in glucagon-treated liver tissues and primary hepatocytes, and mitigated glucagon-elicited hyperglycemia. Based on these results, we conclude that Prom1 regulates hepatic PKA signaling via radixin functioning as an A kinase-anchored protein (AKAP).

cell biology↗