Thermostable Human Basic Fibroblast Growth Factor (TS-bFGF) Engineered with a Disulfide Bond Demonstrates Superior Culture Outcomes in Human Pluripotent Stem Cell.

Human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs) can differentiate into various tissues and are an essential source of various disease models and therapeutics. Various growth factors are required in order to culture pluripotent stem cells, among which basic fibroblast growth factor (bFGF) is essential for maintaining stem cell ability. However, bFGF has a short half-life (8 h) under normal mammalian cell culture conditions, and its activity decreases after 72 h, posing a serious problem in the production of high-quality stem cells. Here, we evaluated the various functions of pluripotent stem cells (PSCs) by utilizing an engineered thermostable bFGF (TS-bFGF) that is thermally stable and maintains activity longer under mammalian culture conditions. PSCs cultured with TS-bFGF showed better proliferation, stemness, morphology, and differentiation than cells cultured with wild-type bFGF. In light of the importance of stem cells in a wide range of applications in the medical and biotechnology fields, we anticipate that TS-bFGF, as a thermostable and long-acting bFGF, can play a key role in securing high-quality stem cells through various sets of stem cell culture processes.

Improved Wound Healing and Skin Regeneration Ability of 3,2'-Dihydroxyflavone-Treated Mesenchymal Stem Cell-Derived Extracellular Vesicles.

Flavonoids enhance the self-renewal and differentiation potential of mesenchymal stem cells (MSCs) and have therapeutic activities, including regenerative, anti-oxidative, and anti-inflammatory effects. Recent studies have revealed that MSC-derived extracellular vesicles (MSC-EVs) have therapeutic effects on tissue regeneration and inflammation. To facilitate further research on the therapeutic potential of MSC-EVs derived from flavonoid-treated MSCs, we surveyed the production of EVs and their therapeutic applications in wound regeneration. MSCs treated with flavonoids enhanced EV production twofold compared with naïve MSCs. EVs produced by MSCs treated with flavonoids (Fla-EVs) displayed significant anti-inflammatory and wound-healing effects in vitro. The wound-healing capacity of EVs was mediated by the upregulation of mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) signaling. Interestingly, the protein level of p-ERK under inhibition of MEK signals was maintained in Fla-EV-treated fibroblasts, suggesting that Fla-EVs have a higher therapeutic potential than naïve MSC-EVs (Cont-EVs) in wound healing. Moreover, the in vivo wound closure effect of the Fla-EVs showed significant improvement compared with that of the flavonoid-only treatment group and the Cont-EVs. This study provides a strategy for the efficient production of EVs with superior therapeutic potential using flavonoids.

The Orphan GPR50 Receptor Regulates the Aggressiveness of Breast Cancer Stem-like Cells via Targeting the NF-kB Signaling Pathway.

The expression of GPR50 in CSLC and several breast cancer cell lines was assessed by RT-PCR and online platform (UALCAN, GEPIA, and R2 gene analysis). The role of GPR50 in driving CSLC, sphere formation, cell proliferation, and migration was performed using shGPR50 gene knockdown, and the role of GPR50-regulated signaling pathways was examined by Western blotting and Luciferase Assay. Herein, we confirmed that the expression of G protein-coupled receptor 50 (GPR50) in cancer stem-like cells (CSLC) is higher than that in other cancer cells. We examined that the knockdown of GPR50 in CSLC led to decreased cancer properties, such as sphere formation, cell proliferation, migration, and stemness. GPR50 silencing downregulates NF-kB signaling, which is involved in sphere formation and aggressiveness of CSLC. In addition, we demonstrated that GPR50 also regulates ADAM-17 activity by activating NOTCH signaling pathways through the AKT/SP1 axis in CSLC. Overall, we demonstrated a novel GPR50-mediated regulation of the NF-κB-Notch signaling pathway, which can provide insights into CSLC progression and prognosis, and NF-κB-NOTCH-based CSLC treatment strategies.

Advanced 3D dynamic culture system with transforming growth factor-ß3 enhances production of potent extracellular vesicles with modified protein cargoes via upregulation of TGF-ß signaling.

INTRODUCTION: Mesenchymal stromal cells (MSCs) release extracellular vesicles (MSC-EVs) containing various cargoes. Although MSC-EVs show significant therapeutic effects, the low production of EVs in MSCs hinders MSC-EV-mediated therapeutic development. OBJECTIVES: Here, we developed an advanced three-dimensional (a3D) dynamic culture technique with exogenous transforming growth factor beta-3 (TGF-ß3) treatment (T-a3D) to produce potent MSC-EVs. METHODS: Our system enabled preparation of a highly concentrated EV-containing medium for efficient EV isolation and purification with higher yield and efficacy. RESULTS: MSC spheroids in T-a3D system (T-a3D spheroids) showed high expression of CD9 and TGF-ß3, which was dependent on TGF-ß signaling. Treatment with EVs produced under T-a3D conditions (T-a3D-EVs) led to significantly improved migration of dermal fibroblasts and wound closure in an excisional wound model. The relative total efficacy (relative yield of single-batch EVs (10-11-fold) × relative regeneration effect of EVs (2-3-fold)) of T-a3D-EVs was approximately up to 33-fold higher than that of 2D-EVs. Importantly the quantitative proteomic analyses of the T-a3D spheroids and T-a3D-EVs supported the improved EV production as well as the therapeutic potency of T-a3D-EVs. CONCLUSION: TGF-ß signalling differentially regulated by fluid shear stress produced in our system and exogenous TGF-ß3 addition was confirmed to play an important role in the enhanced production of EVs with modified protein cargoes. We suggest that the T-a3D system leads to the efficient production of MSC-EVs with high potential in therapies and clinical development.

Rapid production method with increased yield of high-purity extracellular vesicles obtained using extended mitochondrial targeting domain peptide.

Extracellular vesicles (EVs) are nano-sized membranous structures involved in intercellular communication and various physiological and pathological processes. Here, we present a novel method for rapid (within 15 min), large-scale production of high-purity EVs using eMTDΔ4, a peptide derived from Noxa. The treatment of mesenchymal stem cells derived from human Wharton's jelly after trypsinization and subsequent eMTDΔ4 stimulation in a chemically defined sucrose buffer with orbital shaking led to a substantial increase (approximately 30-fold) in EV production with markedly high purity (approximately 45-fold). These EVs (TS-eEVs) showed higher regenerative and immunomodulatory potential than natural EVs obtained from the culture media after 48 h. The calcium chelator BAPTA-AM and calpain inhibitor ALLM, but not the natural EV biogenesis inhibitor GW4869, blocked the TS-eEV production induced by eMTDΔ4, indicating that the eMTDΔ4-mediated regulation of intracellular calcium levels and calpain activity are closely associated with the rapid, mass production of TS-eEVs. The present study may lead to considerable advances in EV-based drug development and production of stem cell-derived EVs for cell therapy.

Superior therapeutic activity of TGF-ß-induced extracellular vesicles against interstitial cystitis.

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic disease characterized by incapacitating pelvic pain. Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) are considered key mediators of the paracrine action of MSCs and show better biological activities than the parent MSCs, especially in the bladder tissue, which may be unfavorable for MSC survival. Here, we produced MSC-EVs using advanced three-dimensional (a3D) culture with exogenous transforming growth factor-ß3 (TGF-ß3) (T-a3D-EVs). Treatment with T-a3D-EVs led to significantly enhanced wound healing and anti-inflammatory capacities. Moreover, submucosal layer injection of T-a3D-EVs in chronic IC/BPS animal model resulted in restoration of bladder function, superior anti-inflammatory activity, and recovery of damaged urothelium compared to MSCs. Interestingly, we detected increased TGF-ß1 level in T-a3D-EVs, which might be involved in the anti-inflammatory activity of these EVs. Taken together, we demonstrate the excellent immune-modulatory and regenerative abilities of T-a3D-EVs as observed by recovery from urothelial denudation and dysfunction, which could be a promising therapeutic strategy for IC/BPS.

High Therapeutic and Esthetic Properties of Extracellular Vesicles Produced from the Stem Cells and Their Spheroids Cultured from Ocular Surgery-Derived Waste Orbicularis Oculi Muscle Tissues.

Extracellular vesicles (EVs) are paracrine factors that mediate stem cell therapeutics. We aimed at evaluating the possible therapeutic and esthetic applications of EVs prepared from the waste human facial tissue-derived orbicularis oculi muscle stem cells (OOM-SCs). OOM-SCs were isolated from the ocular tissues (from elders and youngsters) after upper eyelid blepharoplasty or epiblepharon surgeries. EVs were prepared from the OOM-SCs (OOM-SC-EVs) and their three-dimensional spheroids. OOM-SCs showed a spindle-like morphology with trilineage differentiation capacity, positive expression of CD105, CD 90, and CD73, and negative expression of CD45 and CD34, and their stem cell properties were compared with other adult mesenchymal stem cells. OOM-SC-EVs showed a high inhibitory effect on melanin synthesis in B16F10 cells by blocking tyrosinase activity. OOM-SC-EVs treatment led to a significant attenuation of senescence-associated changes, a decrease in reactive oxygen species generation, and an upregulation of antioxidant genes. We demonstrated the regeneration activity of OOM-SC-EVs in in vitro wound healing of normal human dermal fibroblasts and upregulation of anti-wrinkle-related genes and confirmed the therapeutic potential of OOM-SC-EVs in the healing of the in vivo wound model. Our study provides promising therapeutic and esthetic applications of OOM-SC-EVs, which can be obtained from the ocular surgery-derived waste human facial tissues.