Stem Cell Reviews and Reports最新文献

Investigation of toxicological profile and possible side effects of engineered nanomaterials (ENMs) is of high importance. Historically, two-dimensional (2D) cell culture was used to study the toxicity of the ENMs, but due to their inability to simulate in vivo cell behavior, three-dimensional (3D) cell culture systems have been developed. Nanotoxicity studies initiate with in vitro experiments and continue with in vivo studies, which are very challenging and sometimes accompanied by conflicting data due to the in vitro-in vivo gap. Thus, scientists are turning their attention to microfabrication techniques and engineered systems "called organ-on-a-chips", which act as an intermediate between in vivo and in vitro systems. The present account tries to review the classical study models and suitably cover the emerging 3D culture models including scaffold-free and scaffold-based 3D cell cultures, 3D co-culture with direct contact and without cell-cell contact methods as well as microfluidic-based tissue chips and organoids. Overall, this review aims to give readers a better insight about the ENMs' toxicology and fill the gaps between the knowledge and practical techniques. Hopefully, the presented information will resolve the issues of 2D in vitro cultures and display the clinically relevant responses to the concerns of therapeutic ENMs.

Mesenchymal stem cells (MSCs) are highly valuable for their potential in cell therapy and tissue engineering because of their self-renewal, multilineage differentiation, and immunomodulatory capabilities. Adipose-derived mesenchymal stem cells (AD-MSCs) are advantageous in regenerative medicine because of their accessibility and ease of isolation. However, the clinical application of MSCs faces challenges related to large-scale culture (LSC) expansion, which is required to generate enough cells for transplantation but also decreases their therapeutic properties. This review assesses the impact of LSC on MSC functionality, differentiation potential, and immunomodulatory properties, and identifies key factors, such as metabolic shifts, genetic instability, and altered secretory profiles, that can compromise their therapeutic potential. We explored how prolonged in vitro passaging decreases MSC functionality and increases the risk of genetic alterations. In addition, strategies to preserve the efficacy of MSCs during scaling are discussed. A comprehensive literature review was conducted using PubMed, focusing on in vitro and in vivo studies that evaluated the effects of LSC on MSCs. These findings provide insights into optimizing culture protocols to maintain the clinical efficacy of AD-MSCs in regenerative therapies, addressing the critical need to balance large-scale expansion and functional integrity.

Objective: The global shortage of platelets presents a significant challenge in healthcare. Although human induced pluripotent stem cells (hiPSCs) offer a renewable source for ex vivo platelet production, the current approach remains constrained by heterogeneity, low yield, and high costs. This study introduces an optimized differentiation scheme (ODS) to improve ex vivo platelet differentiation from hiPSCs.

Methods: A systematically optimized culture protocol was developed, incorporating: (1) a higher initial dose of embryoid body (EB) cells, (2) refining culture medium, (3) substitution of cytokines with small molecules, and (4) enhancement of megakaryocyte (MK) polyploidization via small-molecule supplementation. Feasibility and effectiveness were evaluated using microscopy, cell counting, flow cytometry, Wright-Giemsa staining, immunofluorescence (IF), and transmission electron microscopy (TEM).

Results: Increasing the initial EB cell count significantly promoted megakaryocyte production and accelerated the process. A serum-free medium supplemented with human platelet lysate (HPL) was favorable for megakaryocyte generation. Small molecules 740Y-P and butyzamide effectively substituted SCF and TPO for differentiation, while the combination of blebbistatin and 616452 enhanced megakaryocyte maturation. Mature megakaryocytes continuously generated functional platelets that, upon thrombin activation, facilitated fibrin clot formation and contraction in vitro. This method shortened differentiation to 19 days, enhanced output to 1.42 CD41⁺ megakaryocytes and 14.9 platelets per iPSC, and reduced costs by 58.3%.

Conclusion: We have established a cost-effective strategy for platelet production via hiPSC differentiation, with potential applications in cell therapy and gene editing.

Background: Takotsubo syndrome (TTS), also known as stress-induced cardiomyopathy, is characterized by transient left ventricular dysfunction often triggered by emotional or physical stress. Catecholamines are believed to play a pivotal role in the pathogenesis of TTS, including endothelial dysfunction. This study aimed to elucidate the catecholamine-induced endothelial dysfunction using patient-specific induced pluripotent stem cell-derived endothelial cells (hiPSC-ECs) from TTS patients.

Methods: hiPSC-ECs derived from a TTS patient (TTS-hiPSC-ECs) and three healthy donors (HD-hiPSC-ECs) were treated with epinephrine (Epi), Lipopolysaccharide (LPS), or a combination of both, and cell functional responses were evaluated.

Results: Epi exposure significantly impaired endothelial cell functions, evidenced by reduced cell migration, nitric oxide (NO) production, Dil-Ac-LDL uptake, mitochondrial membrane potential (MMP), ATP production, and inhibited tube formation and wound healing in both HD-hiPSC-ECs and TTS-hiPSC-ECs. Additionally, catecholamine treatment resulted in increased concentrations of endothelin-1 (ET-1), angiotensin II (Ang II), and reactive oxygen species (ROS) in the supernatants of both cell types. Elevated Mincle expression and pro-inflammatory cytokines, including IL-6 and IL-1β, along with reduced IL-4 protein expression, were observed in both HD-hiPSC-ECs and TTS-hiPSC-ECs. Furthermore, LPS treatment enhanced Mincle, IL-6, and IL-1β protein expression and reduced IL-4 levels in both cell types. The combination of LPS and Epi enhanced not only the level of those inflammatory factors but also the PI3K/NF-κB signaling pathway in both HD-hiPSC-ECs and TTS-hiPSC-ECs. Strikingly, TTS-hiPSC-ECs showed abnormal features even without an Epi challenge.

Conclusions: The study first reveals functional abnormalities of hiPSC-ECs from a TTS patient and underscores the critical involvement of inflammatory signaling in catecholamine-induced endothelial dysfunction in TTS.

Regenerative medicine promises the possibility of custom-made, ready-to-use human organs without the risk of immune rejection. Human pluripotent stem cells (hPSCs) are the workhorses of stem cell-based tissue engineering. With inherent capabilities to adopt nearly any cellular form, they are supposed to solve the soaring demand for transplantable organs. Technically, PSCs are converted into cells of interest using a stepwise approach (differentiation) mimicking embryonic development. Animal models have been crucial in advancing our understanding of human embryology, mainly due to the widespread conservation of the mammalian regulome. Differentiation protocols have evolved with time from two-dimensional (2D) monocultures, which are relatively easy to maintain, to more complex three-dimensional (3D) organoids that enhance the capacity for staging multilineage assemblies. The appeal of 3D systems lies in their operational resemblance to the actual morphology of tissues. While each platform has pros and cons, its specific strengths can be leveraged to tell a more compelling story of development and how complex pathologies take root. Here, we reviewed key methodologies for the in vitro production of human functional cell lineages from hPSCs. We have connected the most recent science to the work that came before and analyzed where the trends we see now might lead. We examined the shift from 2D cell monolayers to 3D organoids. Additionally, we highlighted hybrid approaches and innovative discoveries that support the reliable generation of physiologically mature cells, enabling the study of development and disease at new depths.