Skeletal muscle stem cells (SkMSCs) are essential for muscle regeneration and represent a promising therapeutic target for muscle disorders. However, effective strategies to precisely regulate SkMSC fate by integrating biochemical and mechanical cues remain limited.

Temozolomide (TMZ) resistance in glioblastoma (GBM) remains a critical barrier to treatment success, driven by O6-methylguanine-DNA methyltransferase (MGMT) overexpression, glioma stem cell (GSC) persistence, and redox adaptation.

Early-life exposure to general anesthetics, particularly propofol, elevates the risk of neurodevelopmental impairment and cognitive sequelae in pediatric populations, representing a pivotal concern in translational neuroanesthesiology. Although preclinical studies have linked propofol to increased developmental neurotoxicity, the underlying molecular mechanisms remain elusive. Our previous work established that nuclear fragile X mental retardation-interacting protein 1 (NUFIP1)-engineered exosomes from human umbilical cord mesenchymal stem cells could mitigate propofol-induced neurotoxicity and neuronal apoptosis in neonatal rats during a critical postnatal window of synaptogenesis (postnatal days 7-14). The present study provides the first mechanistic insights by performing transcriptomic profiling to link this neuroprotection to the endoplasmic reticulum stress (ERS) apoptotic pathway. Importantly, we directly validated key ERS/apoptosis markers and functionally confirmed the pathway's role through pharmacological rescue experiments with Salubrinal. In conclusion, NUFIP1-engineered exosomes regulate propofol-induced nerve injury through the ERS apoptotic pathway, offering novel mechanistic insights with potential implications for addressing pediatric neurodevelopmental impairments.

Obesity imposes dysfunction of the endogenous cellular reparative system, which may manifest as impaired adipose tissue-derived mesenchymal stem/stromal cells (AT-MSCs) function or altered characteristics of circulating endothelial progenitor cells (EPCs). However, whether both systems are abnormal in patients with obesity remains unclear. We hypothesized that human obesity induces impairment of MSCs and EPCs that would be reversed after weight-loss surgery (WLS).

Information on the maintenance of tissue homeostasis is important for developing effective therapeutic methods. However, reports on the cellular composition and tissue stem cells of the larynx are scarce. Therefore, we analyzed mouse laryngeal mucosa using single-cell RNA- sequencing and spatial transcriptomics by photo-isolation chemistry, and we also generated laryngeal organoids as an in vitro model. Consequently, we found a SOX9-positive basal cell subpopulation and a Lgr5-positive cell subpopulation in the mouse vocal fold, and obtained three types of epithelial organoids from laryngeal epithelium. We also confirmed the differences in pseudostratified ciliated columnar epithelium characters between the supraglottis and subglottis of the mouse larynx. These findings provide valuable insights and tools for future research in laryngology and stem cell biology.

FLT3-ITD inhibitors are approved for acute myeloid leukemia (AML) treatment but relapse is common. In this study, the combined inhibition of FLT3-ITD signal and protein translation by QUIZartinib and Omacetaxine Mepesuccinate (QUIZOM) synergistically suppressed the most critical FLT3-ITD survival signals including mitochondrial respiration and proteostasis, which induced apoptosis and pro-inflammatory response. In a Phase 2 trial (NCT03135054) involving 40 chemo-refractory/unfit FLT3-ITD AML patients, QUIZOM achieved a composite complete remission (CRc) of 83%, a median leukemia-free survival (LFS) of 10 months (Range: 0.7-68.2 months) and a median overall survival (OS) of 12.9 months (Range: 1.8-69.2 months). 13/33 (39%) received allogeneic HSCT after a median of 143 days (Range: 53-367 days). Higher CRc rates were observed in patients with NPM1 mutations, DNMT3A mutations, and wild-type WT1. Single-cell RNA-sequencing of QUIZOM cohort revealed positive correlation between pro-inflammatory response in blasts, CD8 + T activation and clinical responsiveness. Further, we identified a leukemic stem cell (LSC) subpopulation with activated JNK/JUN/HSPA1B axis via PLD1-driven phosphatidylcholine metabolism, which promoted proteostasis and drove QUIZOM resistance. PLD1-inhibitor remodeled phospholipid metabolism, induced ferroptosis and restored QUIZOM response in LSC. Our findings provided the therapeutic and resistant mechanisms of QUIZOM and paved the way for targeted interventions in this AML subtype.

While genetic screens have facilitated the dissection of protein function in animal development, advances in systematic point mutagenesis open new opportunities for forward genetics in mammalian cells. Here, we develop a CRISPR/Cas9-mediated base editing screen that allows functional screening of extensive collections of single amino acid substitutions of endogenous proteins. We demonstrate the application on the X-chromosomal Hprt and the autosomal Msh2 gene in diploid male and haploid mouse embryonic stem cells, respectively. Finally, we use this methodology to generate a sequence-function map of the transcriptional co-repressor SPEN in X chromosome inactivation. We demonstrate that the substitution of the SPEN RRM4-residue W522 abrogates X-linked gene repression by Xist RNA and impairs the establishment of H3K27me3 deposition. Our results demonstrate that screening in haploid cells allows efficient identification of mutations that would be recessive in diploid cells, suggesting applications across a wide range of areas.

Hematopoietic stem cells (HSCs) survive many types of cellular stress but often lose their regenerative and lymphopoietic capacities as a result. Such functional decline also occurs with age, and dysfunctional HSCs with impaired mitochondria accumulate during aging. However, the molecular link between HSC stress response and age-related functional decline remains poorly understood. Here we show that multiple stress responses converge on the RIPK3-MLKL axis to induce age-related changes in HSCs. The necroptosis effector MLKL is readily activated by inflammation and replication stress and accumulates in HSC mitochondria. Consequently, activated MLKL does not cause cell death but impairs HSC self-renewal and lymphoid differentiation. Such MLKL-mediated functional decline also occurs in HSCs during organismal aging, with activated MLKL primarily mediating age-related mitochondrial damage and reduced glycolytic flux. Collectively, our results establish the RIPK3-MLKL axis as a key mediator of HSC aging and identify a necroptosis-independent role of MLKL in mitochondrial damage.

Leucine-rich repeat-containing G protein-coupled receptor 5 (LGR5) is an established marker of normal and cancer stemlike cells. LGR5 has been implicated in promoting cancer cell plasticity that drives tumorigenesis, metastasis, and therapeutic resistance. LGR5 rapidly and constitutively internalizes and potentiates Wnt (Wingless/Int-1)/β-catenin and adhesion signaling pathways, though its precise mechanisms and interacting partners remain unresolved. An improved understanding of LGR5 signaling may provide invaluable insight into its intricate and important functions in cancer progression. Moreover, several LGR5-targeting therapies, including peptibody- and antibody-drug conjugates and bispecific antibodies, are showing promising efficacy and tolerability in colorectal cancer and other tumor types. This review discusses the cancer-related functions of LGR5 and explores the preclinical and clinical approaches to therapeutically target this enigmatic protein.

Protein tyrosine phosphatase receptor type Z1 (PTPRZ1) is one of the most abundantly expressed and enriched genes in astrocytes during development, yet its function in astrocytes is unknown. Using an astrocyte-neuron co-culture system, we found that knockdown of Ptprz1 in astrocytes significantly impaired astrocyte branching morphogenesis. To investigate the function of PTPRZ1 in astrocytes during brain development, we generated a Ptprz1 conditional knockout mouse and deleted Ptprz1 from astrocytes postnatally, after the bulk of astrogenesis is complete. At postnatal day 21, we found subtle changes in astrocyte morphology and a reduction in the density of co-localized pre and post synaptic excitatory synapse markers across multiple layers of the visual cortex in both male and female mice, suggesting important functions for astrocytic PTPRZ1 in both astrocyte morphogenesis and synaptogenesis. PTPRZ1 is expressed in several neural cell types, including radial glial stem cells and oligodendrocyte progenitor cells (OPCs), and regulates critical aspects of neurodevelopment, including neurite outgrowth, neuronal differentiation, myelination, and extracellular matrix (ECM) development. Moreover, altered PTPRZ1 expression is associated with schizophrenia and glioblastoma. Therefore, this mouse model is a valuable resource for investigating cell-type-specific PTPRZ1 function in numerous neurodevelopmental and neuropathological mechanisms.Significance Statement PTPRZ1 is an abundant, astrocyte-enriched protein linked to neurological dysfunction; however, its astrocyte-specific functions are unknown. We generated a Ptprz1 conditional knockout mouse and found that astrocyte-specific deletion of Ptprz1 reduces the density of co-localized excitatory synapse markers in the developing mouse cortex, with mild impact to astrocyte morphology. PTPRZ1 is an emerging therapeutic target for glioblastoma and neurodegeneration. This study provides a new tool to study PTPRZ1 function in neurodevelopment and neuropathology.

The objective of this in vitro study was to evaluate the possible regenerative effects of dehydrated human amnion chorion membrane (ACM) on cell proliferation, migration, and differentiation/mineralization of bone marrow-derived stem cells (BMSCs). The dehydrated human ACM has been commonly used in periodontal regeneration and ridge augmentation procedures due to its membrane properties and growth factors. For the study, commercially available bone marrow-derived stem cells were thawed, cultured, and exposed to different concentrations of amnion-chorion membrane extract (50, 100, 200, 500, and 1000 μg/mL) in mesenchymal stem cell basal media. Cell proliferation was analyzed using the WST-1 assay, migration with the scratch-wound assay, and differentiation/mineralization with Alizarin Red S staining. Two-way ANOVA was used to assess the effects of concentration and time, with pair-wise comparisons made using Fisher protected least significant difference at a 5% significance level. Results showed that the control, 50 μg/mL, and 100 μg/mL groups exhibited lower cell proliferation compared with the 500 μg/mL and 1000 μg/mL groups. Lower concentrations also displayed reduced cell migration compared with the higher concentrations. In the mineralization assay, the control, 200 μg/mL, and 500 μg/mL groups exhibited lower cell mineralization compared with 1000 μg/mL. Temporally, shorter durations showed higher levels of cell migration and lower levels of cell mineralization. Overall, the use of amnion-chorion membrane positively affected cell proliferation, migration, and mineralization, with increased concentrations of amnion-chorion membrane extract yielding greater benefits. This study indicates that amnion-chorion membrane may enhance stem cell activities due to the presence of growth factors in the membrane. These findings are preliminary and must be interpreted cautiously. Further in vivo and clinical studies are necessary to validate these observations.

Human embryonic stem cell (hESC)-derived hepatocytes (hEHs) display functional deficits, particularly impaired albumin secretion and ammonia metabolism, compared to primary human hepatocytes (PHHs). Here, we investigated the regulatory role of CCAAT/enhancer-binding protein beta (C/EBPβ) in hepatocyte maturation. Forced C/EBPβ expression enhanced hepatocyte functionality and upregulated hepatocyte-specific genes, while suppressing epithelial-mesenchymal transition (EMT) via downregulating canonical EMT markers. Mechanistically, CUT&Tag and luciferase reporter assays confirmed C/EBPβ directly binds to the promoter regions of CDH1 (E-cadherin) and CPS1 (carbamoyl phosphate synthetase 1). Co-immunoprecipitation identified an interaction between C/EBPβ and the MAPK pathway. RNA interference combined with Western blot analysis revealed that MAPK1-mediated phosphorylation of C/EBPβ at Thr-235 augmented its transactivation activity, accelerating hepatocyte maturation. Our findings establish C/EBPβ as a master regulator that coordinates transcriptional networks and post-translational modifications during hEHs maturation, providing novel insights for generating mature hepatocytes for disease modeling and regenerative medicine applications. The transcriptional activity of C/EBPβ is regulated by MAPK1 protein within the ERK/MAPK signaling pathway. MAPK1 moves from the cytoplasm into the nucleus and transfers phosphate groups to C/EBPβ. This process reverses the "self-inhibition" state of C/EBPβ and enhances its transcriptional activity on downstream target genes.

Electrical stimulation (ES) is emerging as a non-pharmacological neuromodulation strategy, but its direct impact on human dopaminergic neurons and its relationship to rapid-acting antidepressant mechanisms remain unclear. This study aimed to investigate whether brief biphasic low-frequency low-intensity (LF-LI) ES can induce structural and molecular plasticity in human induced pluripotent stem cell (iPSC)-derived mesencephalic dopaminergic neurons, identify the underlying signaling mechanisms, and evaluate its potential to rescue cortisol-induced impairments as in-vitro endocrine model of depression. iPSC-derived dopaminergic neurons were exposed to LF-LI ES using a custom culture-compatible stimulator, and structural plasticity was quantified three days later by computer-assisted morphometry. Pharmacological blockers, quantitative PCR and Western blot analyses were employed to assess calcium influx, brain-derived neurotrophic factor (BDNF)-TrkB-extracellular signal-regulated kinase (ERK)-mTOR signaling, and dopamine D3 auto-receptor roles in mediating LF-LI ES effects. A single 1h LF-LI ES session at 4 mA induced robust increases in maximal dendrite length, primary dendrite number, and soma area, comparable to 1 μM ketamine. LF-LI ES rapidly enhanced ERK and p70-S6K phosphorylation and required L-type voltage-gated calcium channels, TrkB and mTOR, as their inhibition prevented structural remodeling. LF-LI ES increased dopamine D3 auto-receptors mRNA, and its antagonism attenuated LF-LI ES-induced plasticity. In cortisol-treated neurons, LF-LI ES fully reversed dendritic hypotrophy and soma shrinkage. In conclusion, brief LF-LI ES elicits long-lasting, ketamine-like structural and molecular plasticity in human dopaminergic neurons and rescues stress hormone-induced impairments, supporting LF-LI ES-based neuromodulation approaches targeting dopaminergic circuits in major depressive disorder and treatment-resistant depression.

The blood-brain barrier (BBB) comprised of the brain capillary endothelial cells (BCECs), with its tight junctions (TJ), transporters and receptors, regulates the passage of solutes, such as nutrients, metabolites, and xenobiotics, including drugs. In Alzheimer's disease (AD), characterised by the accumulation of amyloid-β peptide (Aβ) and the formation of hyperphosphorylated tau aggregates, a compromised BBB integrity was reported. There is a lack of knowledge about the effects of tau pathology on BBB function in AD. Advances in developing BBB models using human induced pluripotent stem cell (hiPSC)-derived BCECs have opened a new avenue for investigating AD-related changes in BBB functional integrity. Here, we characterised the BBB model derived from hiPSCs generated from an AD patient with a tau-related mutation (STBCi 062-A) versus the one based on a healthy person's cells (UKKi 011-A) in terms of mimicking AD-related changes in paracellular permeability, TJs, transporters, receptors and other proteins playing a role in BBB integrity. The STBCi 062-A-derived BCECs showed lower TEER values and increased permeability associated with downregulation of proteins regulating TJ organization and BBB integrity, as compared to UKKi 011-A-derived BCECs. We revealed AD-relevant increase in protein expression of efflux transporter BCRP and amino acid transporter ASCT1, as well as transferrin receptor protein 1 in the STBCi 062-A-derived BCECs compared to UKKi 011-A-derived BCECs. The developed AD-patient-hiPSC-derived BCEC model possesses several important characteristics that recapitulate changes in BBB integrity in AD and can serve as a robust tool for developing AD treatments.

Diabetic cataract is characterized by early lens opacification. This study identifies a pathogenic axis that involves the N6-methyladenosine (m6A) demethylase fat mass and obesity-associated protein (FTO) and the mitochondria-enriched long non-coding RNA (lncRNA) RMRP. Transcriptomic analysis of lens epithelial cells (LECs) under high-glucose stress revealed that lncRMRP was the most significantly downregulated lncRNA, while FTO was specifically upregulated. High glucose stimulated FTO to bind to RMRP, removed its m6A methylation, and expedited its degradation. Knockdown of RMRP led to mitochondrial DNA depletion, loss of respiratory chain subunits I, III, and V, bioenergetic failure, and structural damage. Notably, inhibition of FTO restored RMRP levels and rescued mitochondrial function under high-glucose conditions. In mice, overexpression of FTO in the anterior chamber induced lens opacification and mitochondrial defects, both of which were alleviated by co-expressing RMRP. In a mouse model of streptozotocin-induced diabetes, intracameral AAV-RMRP delivery restored RMRP expression specifically in LECs, suppressed cataract formation, alleviated cellular energy deficits, and restored mitochondrial DNA copy numbers and key mitochondrial biogenesis regulators. This work uncovers a new mechanism in diabetic cataracts: chronic hyperglycemia upregulates FTO, which degrades RMRP-causing mitochondrial dysfunction and lens opacity. Critically, rescuing RMRP function in a physiologically relevant diabetic model validates it as a promising therapeutic target for diabetic cataracts.

Alginate, a natural polysaccharide [(1 → 4)-linked β-D-mannuronate and α-L-guluronate], is commonly used in hydrogel form in the biomedical field, including wound healing, drug delivery, and tissue engineering applications. The type and density of cross-linking are key parameters determining the physicochemical and mechanical properties of the hydrogel. However, most of the crosslinking reagents used are generally toxic, requiring extensive modifications and limiting their applicability. Alginate readily forms ionic hydrogels through coordination with divalent cations such as Ca2+ and Ba2+; however, these physically crosslinked networks exhibit poor mechanical integrity under aqueous and in-vivo conditions. Consequently, there is a critical demand for cross-linking agents that are biocompatible, non-toxic, hydrolytically stable, rapidly gelling, and cost-effective to overcome these limitations. In this study, alginate-based 3D hydrogel scaffolds were prepared in a completely green synthetic way using caffeine-catalyzed citric acid-poly(ethylene glycol) (PEG)/poly(propylene glycol) (PPG) as the cross-linker system. The thermal stability, swelling, rheology as well as compressive strength of the hydrogels were investigated and optimized. The developed hydrogel scaffolds containing PPG withstood compressive deformation in both dry and swollen states without any damage and recovered their initial shape after unloading, indicating that the hydrogels possess a certain shape recovery property. In-vitro biological studies with human adipose stem cells revealed that both scaffold types were cytocompatible and showed good hemocompatibility. Overall, the green synthesis of biocompatible and mechanically resilient alginate-CA-PEG scaffolds highlights their potential as versatile biomaterials for prospective medical applications, particularly in soft tissue engineering.

Patients with high-risk (HR) leukemia remain at substantial risk of early relapse, treatment-related toxicity, and poor survival, underscoring the need for effective relapse prevention therapies. To our knowledge, this first-in-human, disease burden-guided study evaluated the feasibility, safety, and efficacy of donor-derived allogeneic interleukin-15-activated cytokine-induced killer cells (IL15-CIK) combining T-cell and natural killer cell properties for post-transplant disease control.

Both the levels and duration of gene expression play critical roles in many biological processes. Recent studies have further revealed that the dynamics of oscillatory versus sustained gene expression also provide essential regulatory information during cell proliferation and differentiation. Oscillatory expression, governed by intracellular negative feedback loops and intercellular coupling with appropriate delays, promotes the proliferation of stem cells, whereas sustained expression typically drives cells toward quiescence or differentiation. Over time, oscillations can result in the gradual upregulation or downregulation of downstream factors or shifts in phase relationships between distinct oscillators, thereby functioning as a timer for cell state transition. Moreover, oscillation frequency encodes critical cues for cell fate choice. Thus, oscillatory dynamics add an extra dimension to the informational landscape of gene expression. Here, we discuss recent advances in our understanding of how oscillatory gene expression is regulated and how it influences the proliferation and differentiation of stem cells.

Adult stem cells maintain tissue homeostasis, yet are themselves vulnerable to loss. One common mechanism to replace lost stem cells is dedifferentiation, in which progeny revert to stem cell identity. It is a paradox how stem cells and progeny retain the same stem cell potential while exhibiting distinct current identities of self-renewal, differentiation, and dedifferentiation. Here, we show that the Drosophila male germline lineage solves this paradox via two parallel and complementary mechanisms to separate potential and identity. First, differentiating progeny maintain stem cell potency by inheriting perdurant stem cell mRNAs without actively transcribing them. Second, two known niche signals (Bmp and Jak-Stat) activate distinct sets of targets, defining three identities (self-renewal, differentiation, and dedifferentiation) based on the combination of their on/off states. Together, this study reveals how a pool of dedifferentiation-competent progeny is maintained to regenerate stem cells as needed without resulting in stem cell overproduction and resolves the puzzle of why most stem cell systems require multiple independent niche signals.