Osteosarcoma (OS), chondrosarcoma (CHS), and Ewing sarcoma (EwS) are the most common primary bone cancers (BCs). Among primary malignant tumors of the bones, OS is the most common, mainly affecting young people (4.8 per 1,000,000). The treatment of bone cancer (BC) is challenging for current medicine owing to its substantial incidence and the vast heterogeneity of malignant lesions within bone tissue. Due to the limitations of current therapies, researchers developed new strategies to treat BC. Exosomes (EXOs) play a crucial role in the development, progression, metastasis, and drug delivery of BCs, such as OS, EwS, and CHS. Hierarchical translation via tissue-specific reactions and cell-specific molecular signaling pathways accounts for the various therapeutic effects of EXOs produced from stem cells. The aim of this review is to highlight the critical role of EXOs derived from multiple cells, such as mesenchymal stem cells, immune cells, and tumor cells, in BCs, including OS, CHS, and EwS. Additionally, we provide a concise overview of how tumor-derived EXOs induce BCs. To lessen the adverse effects of EXOs on patients with BC and to provide more effective and focused treatments, it is necessary to understand these pathways. Moreover, we reviewed the potential of using EXOs as drug delivery systems for the treatment of BCs. Finally, we discussed the pros and cons of this therapeutic approach for BCs.

Multiple sclerosis (MS) leads to histological changes, which in turn result in functional deficits. Studies have reported that bone marrow mesenchymal stem cells (BMSCs) have therapeutic benefits in MS. In addition, sleep deprivation affects therapeutic potential of BMSCs. This research aimed to evaluate the effects of BMSCs compared to sleep-deprived BMSCs (SD-BMSCs) on the motor behavior and histological recovery in MS. The mice were divided into four groups receiving cuprizone for five weeks, with or without intranasal administration of cells (BMSCs or SD-BMSCs) after five weeks. After a two-week recovery period, balance beam and pole tests were performed to assess motor performance, followed by estimation of histological parameters using stereological methods. Mice that received BMSCs scored significantly better than the SD-BMSC group in balance beam and pole tests (P < 0.05). The total cerebellar volume, cortex, and white matter volumes, as well as the total number of Purkinje cells in mice that received BMSCs, were significantly higher compared to those in the SD-BMSC group (P < 0.05). Intranasal administration of BMSCs leads to significantly improved motor behavior and histological regeneration of the cerebellum, including cortex and white matter as well as Purkinje cells compared to SD-BMSCs in a cuprizone model of multiple sclerosis.

Photobiomodulation (PBM), which stimulates cellular functions through light emission, has recently attracted significant attention in regenerative medicine. This study explores the effects of PBM with two wavelengths on human adipose-derived stem cells (ADSCs) and the characteristics of their secreted exosomes in vitro. ADSCs were isolated from human adipose tissue and treated with PBM with 650 nm and 810 nm wavelengths. The therapeutic effects, including cell viability, proliferation, and exosome characteristics, were evaluated using MTT assays, scanning electron microscopy (SEM), BCA assays to determine exosomal protein concentration, and Dynamic Light Scattering (DLS) to assess exosome size distribution. The results indicated that PBM at both wavelengths significantly enhanced ADSCs viability and proliferation, as confirmed by the MTT assay (p = 0.008 for 650 nm laser and p = 0.007 for 810 nm laser). Additionally, exosome analysis revealed that exosomes from PBM-treated groups exhibited a higher protein concentration and an average size of around 86 nm, as measured by BCA and DLS. We concluded that PBM with 650 nm and 810 nm wavelengths individually significantly enhances the proliferation and survival of ADSCs and improves exosome quality in vitro. The treatment increased exosomal protein concentration and improved size distribution, reflecting enhanced cell function. These findings suggest that PBM could be a promising stimulatory approach for improving ADSC-based therapies in regenerative medicine, particularly for tissue repair and chronic wound healing. Further research is needed to explore the molecular mechanisms and clinical applications of ADSCs under the influence of PBM.

Periodontal and craniofacial regeneration presents significant challenges owing to the complex tissue architecture, inadequate vascularization, and diminished stem cell populations within damaged tissues. Traditionally, autologous bone grafts or alternative bone substitute materials have been employed to address these conditions; however, these approaches are constrained by donor site morbidity, limited availability, and suboptimal regenerative efficacy. The advancement of mesenchymal stem/stromal cell (MSC) biology has accelerated the development of cell-based therapies in modern dentistry, which now focuses on biologically driven approaches to regenerate tissues. MSC-based therapies currently under investigation, both preclinically and clinically, show promise for improving tissue integration and healing processes of both soft and hard tissues, attributable to their multipotent nature, immunomodulatory properties, and paracrine signaling capabilities. Nevertheless, obstacles persist, including inconsistent standardization, limited scalability, regulatory hurdles, a paucity of controlled studies, and restricted biomaterial options. This review evaluates MSC-based treatments for periodontal and craniofacial reconstruction by discussing recent research findings and existing obstacles. This review also examines future prospects, such as advanced biofabrication methods, including 3D printing and bioprinting, which have the potential to improve personalized cell therapy for periodontal and craniofacial regeneration.

The extracellular vesicles (EVs) secreted by mesenchymal stromal cells (MSC-EVs) exhibit immunoregulatory functions dependent on their parent cells. MSC-EVs are promising candidates for treating neuroinflammation in neurological diseases due to their acellular nature and their ability to reach the central nervous system. However, the conditions of MSCs for producing EVs with the highest anti-inflammatory efficacy are still unknown. Therefore, the first objective was to study the characteristics of the EVs produced by MSCs cultured in different conditions. The second objective was to evaluate the in vitro anti-inflammatory properties of those EVs in feline stimulated mixed glia. Umbilical cord-derived MSCs were treated with serum-free (SF) media, inflammatory (IF) media, or media supplemented with 5% EV-depleted fetal bovine serum (FBS). The isolated MSC-EVs were characterized by particle size and yield, and their anti-inflammatory ability was evaluated in lipopolysaccharide (LPS) stimulated feline mixed glia. All EV isolates were <160 nm, and the primary mixed glia consisted of microglia, astrocytes, neurons, and endothelial cells. Our results indicate that IF-EVs statistically significantly decreased the production of interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α) and downregulated the transcription of the, nuclear factor kappa B p65 subunit in inflammatory mixed glia after 48 hours. In addition, SF- and FBS-EVs significantly reduced in vitro the secretion of IL-6 after 48 hours, but only SF-EVs achieved a significant effect on inhibiting the expression of p65 at 48 hours. Moreover, messenger RNA (mRNA) levels of inducible nitric oxide synthase (iNOS) were significantly decreased following treatment with SF-EV for 24 hours. This study demonstrates that MSC culture conditions affect the therapeutic potential of the secreted EVs in feline mixed glia.

This study aims to investigate the expression profile and clinical significance of the Troponin T Type 1 (TNNT1) gene across various digestive system tumors. By elucidating the role of TNNT1 in tumor progression, we hope to establish its potential as a prognostic biomarker and therapeutic target.

Ovarian cancer remains one of the most aggressive cancers, and resistance to Poly (ADP-ribose) Polymerase inhibitors (PARPi) poses a major therapeutic challenge. SIRT5, a NAD + -dependent desuccinylase, plays a crucial role in regulating fatty acid metabolism, which is often reprogrammed in cancer cells to promote drug resistance. This study aimed to investigate the potential of polydopamine (PDA)-polymerized antioxidant nanozyme-loaded SIRT5-modified human umbilical cord mesenchymal stem cells (hUCMSCs) to overcome PARPi resistance in ovarian cancer. We employed multi-omics approaches, including transcriptomics, metabolomics, and proteomics, to identify key molecular pathways associated with resistance mechanisms. High-throughput sequencing and metabolic profiling revealed that SIRT5 modifies fatty acid β-oxidation and regulates the desuccinylation of Enoyl-CoA Hydratase (ECHA), a key enzyme involved in this process. In vitro and in vivo experiments demonstrated that nanozyme-engineered hUCMSCs effectively enhanced PARPi resistance by promoting fatty acid metabolism and desuccinylation. These findings suggest that SIRT5-modified hUCMSCs loaded with antioxidant nanozymes offer a promising therapeutic strategy to combat PARPi resistance in ovarian cancer. The study provides new insights into overcoming drug resistance through metabolic reprogramming and enhances the potential of engineered stem cells in cancer therapy.

M2 macrophages are known to be involved in tumorigenesis. However, the mechanism by which they promote tumor progression in endometrial cancer (EC) remains largely unknown. Kynureninase (KYNU) has been found to be associated with the progression of various tumors, but research on endometrium is limited to embryo transfer. Therefore, a better understanding of KYNU as a potential therapeutic target in EC treatment is needed. This study aimed to elucidate the mechanism by which M2 macrophage-secreted KYNU influences the malignant biological and stemness remodeling of EC via the SOD2-mtROS-ERO1α and endoplasmic reticulum unfolded protein response (UPRER) pathway.

Intrinsically resistant glioma stem cells (GSCs) in the setting of a highly immunosuppressive tumor microenvironment (TME) remain the most predominant phenomenon leading to unfavorable therapeutic outcomes in glioblastoma (GBM). Hence there is an unmet need for novel anti-GBM therapeutic paradigms that can effectively target GSCs while simultaneously reprogramming the TME.

Surgical treatment alone is not effective in addressing delayed fracture healing (DFH). This study nvestigates the molecular mechanism underlying fracture healing to identify improved therapeutic strategies.

The majority of cancer cells experience replication stress, which ultimately causes them to enter mitosis with underreplicated DNA. To alleviate the consequences of replication stress, cells utilize a mechanism known as MiDAS that functions to complete synthesis of underreplicated DNA in early mitosis. This process is considered an Achilles heel for highly replicative cancers. In this study, we show that human TopBP1 localizes to sites of underreplicated DNA marked by FANCD2 and promotes MiDAS through recruitment of the nuclease scaffold protein SLX4. Additionally, we demonstrate that the recruitment of SLX4 to TopBP1 foci in mitosis depends on TopBP1-K704, SLX4-T1260, and several SUMO-interaction motifs in SLX4. Lastly, we show that the recruitment of SLX4 to TopBP1 foci in mitosis is important to prevent transmission of DNA damage to daughter cells. Based on this, we hypothesize that targeting the TopBP1-SLX4 interaction in mitosis may be a potential strategy for anti-cancer therapy.

Pancreatic cancer stem cells (PCSCs) are a small population of cells in tumours that exhibit enhanced self-renewal and differentiation capabilities. CSCs proactively remodel the tumour microenvironment to maintain CSC stemness, which contributes to chemotherapy resistance. Compared with targeting PCSCs themselves, targeting the PCSC niche may be a novel strategy for pancreatic cancer (PC) therapy. Here, we found that DSG2, a member of the desmosomal cadherin family, is highly expressed in PCSCs. DSG2 upregulation is correlated with adverse outcomes in PC patients. DSG2 knockdown suppressed IL-4 and GM-CSF expression, which promoted the enrichment of tumour-associated macrophages to establish a supportive PCSC niche. Furthermore, we found that the IL-8/CXCR2 axis interacts with DSG2 to promote PCSC stemness and gemcitabine resistance by activating the Wnt/β-catenin pathway. These findings highlight the novel regulatory mechanism of DSG2 in PC, providing new targets for the development of therapeutics targeting PCSC niches.

mRNA modifications are vital in regulating cellular processes. Beyond N6-methyladenosine (m6A), most other internal mRNA modifications lack dedicated catalytic machinery and are typically introduced by tRNA-modifying enzymes. The distribution and stoichiometry of these modifications on mRNAs remain debated and require further validation. Furthermore, their precise function remains controversial due to the challenges of excluding the intricate combinational effects of tRNA modifications. Here, we biochemically validate that NSUN6, a tRNA structure-dependent methyltransferase, independently catalyzes 5-methylcytidine (m5C) formation with robust activity on mRNA by recognizing the CUCCA motif in a certain stem-loop structure. NSUN6 employs different strategies to recognize tRNA and mRNA substrates. By introducing mutations, we further separate its catalytic capabilities toward mRNA and tRNA revealing that NSUN6 promotes breast cancer cell migration depending on mRNA m5C modification. Mechanistically, a cohort of mRNAs involved in cell migration carries high levels of NSUN6-mediated site-specific m5C modification, thus being stabilized by the preferential binding of m5C readers YBX1 and YBX3. Moreover, introducing a single-site high-level m5C can significantly increase the stability of therapeutic mRNAs in cells. Our findings underscore the pivotal role of m5C-modified mRNAs in promoting breast cancer cell migration and their potential for therapeutic applications.

Current approaches for bone repair predominantly target localized delivery of growth factors that are aimed at the coupling of angiogenesis and osteogenesis. However, delayed revascularization and regeneration of critical-sized bone defects are still challenging. In this study, we engineer an ossification center-like organoid (OCO) that consist of an inner-core bone morphogenetic and neurotrophic spheroid generated via MSCs-loaded 3D printing, alongside the interstitially distributed outer-shell proangiogenic neurotrophic phase. Our results demonstrate that collective implantation of OCOs achieves rapid bone bridging with successive OC-like bone ossicles formation across the bone defect in a "divide-and-conquer" way. Single-cell RNA sequencing analysis unveils a developmentally mimicking stem cell community that dominated with Krt8+ skeletal stem cells (SSCs) is uniquely recruited by the pro-regenerative in-situ organoid fusion and maturation. Particularly noteworthy is the specific expansion of Krt8+ SSCs concomitant with the simultaneous reduction of Has1+ migratory fibroblasts (MFs) post-OCO implantation. Furthermore, cross-species comparisons employing machine learning reveal high resemblance of the relative Krt8+ SSCs/Has1+ MFs composition in bone regeneration with that in public data from developmental bone tissues. Our findings advocate an approach akin to "divide-and-conquer" utilizing engineered OC-like organoids for prompt regeneration of large-sized bone defects.

Peripheral neuropathy is a common complication in diabetes, affecting around 50% of the diabetic population. Co-occurrence of diabetic peripheral neuropathy (DPN) and diabetic bone disease has led to the hypothesis that DPN influences bone metabolism, although little experimental evidence has yet supported this premise. To investigate, mice were fed a high-fat diet (HFD) followed by phenotyping of skeletal-innervating neurons and bone architectural parameters. Results showed that HFD feeding resulted in a marked decrease in skeletal innervation (69%-41% reduction in Beta-III-Tubulin-stained nerves, 38% reduction in CGRP-stained nerves in long bone periosteum). These changes in skeletal innervation were associated with significant alterations in bone mass and in cortical and trabecular bone microarchitecture of long bones. Single-cell RNA sequencing (scRNA-Seq) of sensory neurons and bone tissue was next utilized to reconstruct potential nerve-to-bone signaling interactions, including implication of sensory nerve-derived neurotrophins (Bdnf), neuropeptides (Gal, Calca and Calcb), and other morphogens (Vegfa, Pdgfa, and Angpt2). Moreover, scRNA-Seq identified marked shifts in periosteal cell transcriptional changes within HFD-fed conditions, including a reduction in cell proliferation, an increase in adipogenic differentiation markers, and reductions in WNT, TGFβ, and MAPK signaling activity. When isolated, periosteal cells from HFD-fed mice showed deficits in proliferative and osteogenic differentiation potential. Moreover, these cellular changes in proliferation and differentiation capacity were restored by treatment of HFD-exposed periosteal cells to sensory neuron-conditioned medium. In summary, HFD modeling of type 2 diabetes results in skeletal polyneuropathy. Moreover, the combination of multi-tissue scRNA-Seq and isolated in vitro studies strengthen the case for altered nerve-to-bone signaling in diabetic bone disease.

Hematopoietic stem cells (HSC) with multilineage potential are critical for T cell reconstitution after allogeneic hematopoietic cell transplantation (allo-HCT). The Kitlo HSC subset is enriched for multipotential precursors, but their T cell potential remains poorly characterized. Using a preclinical allo-HCT mouse model, we demonstrate that Kitlo HSCs provide superior thymic recovery and T cell reconstitution, resulting in improved immune responses to post-transplant infection. Kitlo HSCs with augmented bone marrow (BM) lymphopoiesis mitigate age-associated thymic alterations and enhance T cell recovery in middle-aged mice. Mechanistically, chromatin profiling reveals Kitlo HSCs exhibiting higher activity of lymphoid-specifying transcription factors, such as, ZBTB1. Zbtb1 deletion diminishes HSC engraftment and T cell potential; by contrast, reinstating Zbtb1 in megakaryocytic-biased Kithi HSCs rescues hematopoietic engraftment and T cell potential in vitro and in vivo. Furthermore, age-associated decline in Kitlo HSCs is associated with diminished T lymphopoietic potential in aged BM precursors; meanwhile, Kitlo HSCs in aged mice maintain enhanced lymphoid potential, but their per-cell capacity is diminished. Lastly, we observe an analogous human BM KITlo HSC subset with enhanced lymphoid potential. Our results thus uncover an age-related epigenetic regulation of lymphoid-competent Kitlo HSCs for T cell reconstitution.

Duplication 15q (dup15q) syndrome is a leading genetic cause of autism spectrum disorder, offering a key model for studying autism-related mechanisms. Using single-cell and single-nucleus RNA sequencing of cortical organoids from dup15q patient-derived iPSCs and post-mortem brain samples, we identify increased glycolysis, disrupted layer-specific marker expression, and aberrant morphology in deep-layer neurons during fetal-stage organoid development. In adolescent-adult postmortem brains, upper-layer neurons exhibit heightened transcriptional burden related to synaptic signaling, a pattern shared with idiopathic autism. Using spatial transcriptomics, we confirm these cell-type-specific disruptions in brain tissue. By gene co-expression network analysis, we reveal disease-associated modules that are well preserved between postmortem and organoid samples, suggesting metabolic dysregulation that may lead to altered neuron projection, synaptic dysfunction, and neuron hyperexcitability in dup15q syndrome.

Curcumae Rhizoma, a traditional Chinese medicine derived from the dried rhizome of Curcuma species, has long been used to treat liver-related disorders. In the classical medical text Taiping Shenghui Fang, it was recorded for the treatment of hepatocellular carcinoma (HCC) characterized by Qi stagnation and blood stasis. Its major chemical constituents include curcumin and Zedoary Turmeric Oil (ZTO). While curcumin has been extensively studied for its pharmacological activities, the therapeutic potential and mechanism of ZTO in HCC remain insufficiently understood.

Metazoan nucleosomes harboring H3K79 methylation (H3K79me) deposited by the methyltransferase DOT1L (disruptor of telomeric silencing 1-like) decorate actively transcribed genes. While DOT1L regulates transcription and the pathogenesis of leukemia and neurological disorders, the role of H3K79me remains elusive. Here, we reveal a functional synergism between H3K79me and H3K36 trimethylation (H3K36me3) in regulating gene expression and cellular differentiation. Simultaneous catalytic inactivation of DOT1L and the H3K36 methyltransferase SETD2 (SET domain containing 2) leads to hyperactive transcription and failures in neural differentiation. H3K79me/H3K36me3 loss causes increased transcription elongation, gained chromatin accessibility at a group of enhancers, and increased recruitment of TEAD4 (TEA domain transcription factor 4) and its coactivator YAP1 (Yes-associated protein 1) to these enhancers. Furthermore, YAP-TEAD inhibition restores the expression levels of genes hyperactivated by H3K79me/H3K36me3 loss. Together, we demonstrate a synergism of H3K79me and H3K36me3 in regulating transcription and cell fate transition, unveil the underlying mechanisms, and provide insight into targeting diseases driven by misregulation/mutations of DOT1L and/or SETD2.