Glioblastoma multiforme (GBM) is a highly invasive brain tumor, and traditional treatments combining surgery with radiochemotherapy have limited effects, with tumor recurrence being almost inevitable. Given the lack of proliferative capacity in neurons, inducing terminal differentiation of GBM cells or glioma stem cells (GSCs) into neuron-like cells has emerged as a promising strategy. This approach aims to suppress their proliferation and self-renewal capabilities through differentiation. This review summarizes the methods involved in recent research on the neuronal differentiation of GBM cells or GSCs, including the regulation of transcription factors, signaling pathways, miRNA, and the use of small molecule drugs, among various strategies. It also outlines the interconnections between the mechanisms studied, hoping to provide ideas for exploring new therapeutic avenues for GBM and the development of differentiation-inducing drugs for GBM.

The successful generation of long-term engrafting hematopoietic stem cells (HSCs) from human-induced pluripotent stem cells (hiPSCs) has long been sought to revolutionize treatments for hematological disorders, eliminating reliance on donors and avoiding immune rejection, and thus has been seen as a major milestone in regenerative medicine. Previous studies, guided by developmental hematopoiesis, made progress in creating blood cells from hiPSCs, but challenges persisted in producing hematopoietic cells with functional properties of genuine HSCs capable of long-term engraftment. In their recent study, Ng and colleagues described an optimized differentiation protocol that manipulates key signaling pathways, including TGF-β, WNT, BMP, and retinoic acid in a stage-specific manner to generate HSCs with multilineage capacity. This strategy yielded hematopoietic cells capable of engrafting long term with high levels of human chimerism in recipient mice. This research provides a blueprint for future studies aiming for personalized HSC-based therapies for various blood disorders.

Tracheal reconstruction is necessary in patients with large tracheal defects. Previously, artificial tracheae made of polypropylene and collagen sponge have been used clinically by our group. As a basic research aimed at promoting epithelialization for infection defense, we transplanted cell sheets of human induced pluripotent stem cell (hiPSC)-derived airway epithelial cells (iAECs) with artificial tracheae into tracheal defects of rats and confirmed their engraftment. In this study, we examined the difference in the cell engraftment between hiPSC-derived airway epithelial progenitor cells (iAEPCs) and iAECs. Cell sheets were collected on days 38, 45, and 56 of induction into iAECs, then transplanted into nude rats with tracheal defects along with the artificial trachea. Two weeks after transplantation, surviving human nuclear antigen (HNA)-positive epithelial cells were observed none of six rats in the 38-day group, two out of six in 45-day group, and five out of six in the 56-day group. The proportion of surviving HNA+ cells among the epithelial cells of 56-day group was significantly higher those of 38-day group. Differentiated iAECs are more suitable for the transplantation of hiPSCs into tracheal defects. Our findings propose the use of differentiated cells for improvement of engraftment efficiency.

Cord blood (CB) is widely stored as a source of hematopoietic stem cells for potential future use, though its application for autologous purposes remains limited. Repurposing CB into human-induced pluripotent stem cells (hiPSCs) can broaden its utility beyond hematological conditions. This study investigated the effects of umbilical cord-mesenchymal stromal cell (UC-MSC) co-culture on CB CD34 cells and the characteristics of the resulting hiPSCs. CD34 cells were isolated, expanded in UC-MSC co-culture for 3 days, and reprogrammed into hiPSCs using episomal vectors. Results showed that UC-MSC co-culture significantly increased CD34 cell numbers ( < 0.0001, = 6), with a reduced population doubling time of 25.1 ± 2.1 hours compared with the control ( < 0.0004, = 6). The yield of CD34 cells was substantially higher in the UC-MSC co-culture group. The hiPSCs exhibited comparable reprogramming efficiency, pluripotency marker expression, trilineage differentiation potential, and genomic stability to CD34 cells expanded under standard culture conditions. These findings suggest that CD34 cells from CB, expanded in UC-MSC co-culture, can be reprogrammed into functional hiPSCs without compromising cell quality or genetic stability.

Genome editing techniques have potential to revolutionize the field of life sciences. Several limitations associated with traditional gene editing techniques have been resolved with the development of prime editors that precisely edit the DNA without double-strand breaks (DSBs). To further improve the efficiency, several modified versions of prime editing (PE) system have been introduced. Bi-directional PE (Bi-PE), for example, uses two PE guide RNAs enabling broad and improved editing efficiency. It has the potential to alter, delete, integrate, and replace larger genome sequences and edit multiple bases at the same time. This review aims to discuss the typical gene editing methods that offer DSB-mediated repair mechanisms, followed by the latest advances in genome editing technologies with non-DSB-mediated repair. The review specifically focuses on Bi-PE being an efficient tool to edit the human genome. In addition, the review discusses the applications, limitations, and future perspectives of Bi-PE for gene editing.

This study explores the protective mechanism of mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) in diabetic foot ulcer (DFU). Human umbilical cord MSCs (HucMSCs) were identified via osteogenesis and adipogenic differentiation, as well as flow cytometry. EVs were isolated from HucMSCs and characterized using transmission electron microscopy, nanoparticle tracking analysis, and Western blotting. Fluorescence microscopy revealed the uptake of PKH67-labeled EVs and Cy3-labeled microRNA-21-5p (miR-21-5p) by human skin fibroblasts (HSFs). EVs were cocultured with HSFs, and cell proliferation and migration were assessed using Cell Counting Kit-8, colony formation, scratch, and Transwell assays. miR-21-5p overexpression in EVs was evaluated for its role in promoting HSF functions. The expression levels of miR-21-5p, Krüppel-like factor 6 (KLF6), α-smooth muscle actin, and collagen type I alpha 1 chain were analyzed via quantitative real-time PCR and Western blotting. The interaction between miR-21-5p and KLF6 was confirmed through a dual-luciferase reporter gene assay. HucMSC-derived EVs enhanced the proliferation and migration of HSFs under high glucose by delivering miR-21-5p, which targeted and inhibited KLF6. Overexpression of KLF6 counteracted the pro-proliferative and migratory effects of EVs carrying miR-21-5p. Overall, these findings suggest that HucMSC-EVs promote HSF proliferation and migration by downregulating KLF6 via miR-21-5p delivery, offering a potential therapeutic strategy for DFU.

Spermatogenesis constitutes a complex and intricate cascade of differentiation, indispensable for the male reproductive competence. The intercellular communication conduits of Sertoli cells (SCs) are pivotal in orchestrating this cascade ensuring sustenance and development of germ cells. Single cells and bioinformatics recently demonstrated articles are used for the regulatory modalities through which SCs modulate spermatogenesis, specifically androgen receptors (ARs), the transforming growth factor-beta/Smad axis, mitogen-activated protein kinases, cAMP/protein kinase A (PKA), phosphatidylinositol 4,5-bisphosphate 3-kinase (PI3k)/AKT serine threonine kinase (Akt), AMP-activated protein kinase, and AR pathways. Within this framework, homeostasis of gap junction dynamics, cryptic sites and the activities at tight junctions and adherens junctions, with the integrity of the testicular barrier, glucose assimilation, lactate distribution, being governed also along with SC maturation. Disruptions in activities or abnormal concentration in derangements in AR, cAMP/PKA, and PI3k/Akt pathways, and as well as the molecules that comprise them, would present male infertility.

Tumors evade immune detection by downregulating antigen presentation and hindering immune responses. Type 1 conventional dendritic cells (cDC1s) are vital in stimulating cytotoxic T cells against tumors. Ascic et al. are now demonstrating the ability of PU.1, IRF8, and BATF3 (PIB) transcription factors to directly reprogram a plethora of tumors bypassing the suppressive effects of the tumor microenvironment, and leading to overall tumor regression while eliciting a systemic immune response that can protect from secondary tumor induction.

Cloning by somatic cell nuclear transfer (SCNT) remained challenging for Rhesus monkeys, mostly due to its low efficiency and neonatal death. Genome-scale analyses revealed that monkey SCNT embryos displayed widespread DNA methylation and transcriptional alterations, thus including loss of genomic imprinting that correlated with placental dysfunction. The transfer of inner cell masses (ICM) from cloned blastocysts into ICM-depleted fertilized embryos rescued placental insufficiency and gave rise to a cloned Rhesus monkey that reached adulthood without noticeable abnormalities.

Via retrospective isolation of clones using Rewind, Jain et al. identified primed states of cells that reprogram to induced pluripotent stem cells. Examining clones, they find that cells retain memory of over several rounds of cell division. Moreover, they show that extrinsic factors change the number of primed cells, suggesting that there exist diverse paths of reprogramming and states of priming.

Cellular senescence is a state in which cells enter cell cycle arrest. However, senescent cells have the ability to secrete signaling molecules such as chemokines, cytokines, and growth factors. This secretory activity is an important feature of senescent cells, since the secreted factors impact the surrounding cellular microenvironment. Indeed, senescent cells and their secretome play a crucial role during limb development. However, whether the process of limb regeneration also relies on senescent cells remains unclear. Creation of a novel targeted depletion strategy that can eliminate senescent cells in the regenerating limb has now demonstrated an important role for senescent cells in limb regeneration. This role is linked to senescent cell-derived Wnt signaling. These findings reveal a previously unknown role for senescent cells during limb regeneration through Wnt signaling.

The interplay between aging and immune system deterioration presents a formidable challenge to human health, especially in the context of a globally aging population. Aging is associated with a decline in the body's ability to combat infections and an increased risk of various diseases, underlining the importance of rejuvenating the immune system as a strategy for promoting healthier aging. In issue 628 of Nature (2024), Ross et al. present a compelling study that introduces a novel strategy for rejuvenating the aged immune system (Ross et al., 2024). By using antibodies to selectively eliminate "aberrant" hematopoietic stem cells (HSCs), this research opens new avenues for addressing age-related immune deterioration.

Our group generated two induced pluripotent stem cell (iPSC) lines for red blood cell (RBC) production from blood donors with extensively known erythrocyte antigen profiles. One line was intended to give rise to RBCs for transfusions in patients with sickle cell disease (SCD), while the other was developed to create RBC panel reagents. Two blood donors were selected based on their RBC phenotypes, further complemented by high-throughput DNA array analysis to obtain a more comprehensive erythrocyte antigen profile. Enriched erythroblast populations from the donors' peripheral blood mononuclear cells were reprogrammed into iPSCs using nonintegrative plasmid vectors. The iPSC lines were characterized and subsequently subjected to hematopoietic differentiation. iPSC PB02 and iPSC PB12 demonstrated and iPSC features and retained the genotype of each blood donor's RBC antigen profile. Colony-forming cell assays confirmed that iPSC PB02 and iPSC PB12 generated hematopoietic progenitors. These two iPSC lines were generated with defined erythrocyte antigen profiles, self-renewal capacity, and hematopoietic differentiation potential. With improvements in hematopoietic differentiation, these cells could potentially be more efficiently differentiated into RBCs in the future. They could serve as a complementary approach for obtaining donor-independent RBCs and addressing specific demands for blood transfusions.

Mesenchymal stem cell (MSCs) therapy, as a rapidly developing area of medicine, holds great promise for the treatment of a variety of medical conditions. MSCs are multipotent stem cells that can be isolated from various tissues and could self-renew and differentiate. They secrete cytokines and trophic factors that create a regenerative microenvironment and have immunomodulatory properties. Although clinical trials have been conducted with MSCs in various diseases, concerns regarding the possibility of malignant transformation of these cells have been raised. The studies showed a higher rate of hematological malignancy and carcinogenesis in experimental models after MSC transplantation. The mechanisms underlying malignant transformation of MSCs are complex and not fully understood, but they are believed to involve the presence of special signaling molecules and alterations in cell behavior regulation pathways. Possible pathways that lead to MSCs' oncogenic transformation occur through two mechanisms: spontaneous and stimulated malignant transformation, including cell fusion, fusion proteins, and the tumor microenvironment. MSC-based therapies have the potential to revolutionize medicine, and addressing the issue of malignancy is crucial to ensure their safety and efficacy. Therefore, the purpose of the present review is to summarize the potential mechanisms of the malignant transformation of MSCs. [Figure: see text].

Culturing of mouse and human embryonic stem cells (ESCs) was a major breakthrough in the field of stem cell biology. These models gained popularity very soon mainly due to their pluripotency. Evidently, the ESCs of mouse and human origin share typical phenotypic responses due to their pluripotent nature, such as self-renewal capacity and potency. The conserved network of core transcription factors regulates these responses. However, significantly different signaling pathways and upstream transcriptional networks regulate expression and activity of these core pluripotency factors in ESCs of both the species. In fact, ample evidence shows that a pathway, which maintains pluripotency in mouse ESCs, promotes differentiation in human ESCs. In this review, we discuss the role of canonical signaling pathways implicated in regulation of pluripotency and differentiation particularly in mouse and human ESCs. We believe that understanding these distinct and at times-opposite mechanisms-is critical for the progress in the field of stem cell biology and regenerative medicine.