Stem Cell Function Research Articles

Effect of cigarette smoke on the proliferation, viability, gene expression, and cellular functions of adipose-derived mesenchymal stem cells from smoking and non-smoking donors.

Cigarette smoking negatively impacts mesenchymal stem cell functionality, including proliferation, viability, and differentiation potential. Adipose-derived mesenchymal stem cells (ADMSCs) are increasingly used for therapeutic purposes, but the specific effects of smoking in vivo on these cells are poorly understood. This study investigates the effects of cigarette smoke on the proliferation, viability, gene expression, and cellular functions of ADMSCs from smoking and non-smoking donors. In this study, ADMSCs were isolated from healthy smokers and non-smokers, and cell proliferation was assessed using the MTT assay, viability with apoptosis assays, mitochondrial membrane potential (MMP), and gene expression related to oxidative stress and cellular functions. Cell cycle analysis was also conducted. Our findings reveal a significant decrease in the proliferation of ADMSCs from smokers. Apoptosis assays showed reduced viable cells in smokers without a significant change in MMP, suggesting alternative pathways contributing to decreased viability. Gene expression analysis indicated the upregulation of genes associated with oxidative stress response and cellular defense mechanisms and the downregulation of genes related to inflammatory signaling, detoxification, and cellular metabolism. Cell cycle analysis indicates cycle arrest or delay in smokers, possibly due to stress and potential DNA damage. Smoking negatively affects ADMSCs' proliferation, viability, and function through oxidative stress and gene expression alterations. These findings highlight the importance of considering smoking status in ADMSC therapies and the need for further research to mitigate the effect of smoking on stem cells.

Foxp3+ regulatory T cells reside within the corneal epithelium and co-localize with limbal stem cells

In this study we investigated the presence of resident Foxp3+ regulatory T cells (Tregs) within the cornea and assessed the role of resident Tregs in corneal epithelial wound healing. Using a mouse model, we showed that in the steady state Foxp3+Tregs are either in close proximity or co-localize with ABCG2+ limbal stem cells. We also showed that these Tregs reside within the epithelial layer and not the corneal stroma. In addition, using a mouse model of mechanical injury, we demonstrated that depletion of Tregs from the cornea prior to corneal mechanical injury, using subconjunctival injection of anti-CD25, was associated with delayed epithelial healing. These results suggest a role for cornea resident Tregs in corneal epithelial cell function and wound healing and opens doors for further exploration of the role of Tregs in limbal stem cell function and survival.

Regulation of α-Ketoglutarate levels by Myc affects metabolism and demethylation in porcine early embryos

The Myc family is essential for cell proliferation, differentiation, and metabolism, particularly in embryonic development and stem cell functions. However, the specific role of Myc in porcine early embryonic development is not fully understood. This study observed high Myc expression during the four-cell stage of porcine embryos. Inhibition of Myc using 10058-F4 impaired embryonic development, disrupted energy metabolism, and increased DNA methylation. Mechanistically, these effects were dependent on α-KG, a TCA cycle intermediate and cofactor for TET demethylation enzymes. Sequencing analysis of four-cell embryos post-Myc inhibition revealed downregulation of key metabolic enzymes related to α-KG, such as CS, IDH2, leading to reduced α-KG levels. Supplementation with α-Ketoglutarate (α-KG) mitigated the negative effects of Myc inhibition, including lower blastocyst rates, decreased ATP levels, and increased 5 mC levels. In conclusion, Myc regulates the expression of key metabolic enzymes during the four-cell stage, influencing early embryonic metabolism and epigenetic reprogramming.

Yes-associated protein-mediated melatonin regulates the function of periodontal ligament stem cells under oxidative stress conditions.

Human periodontal ligament stem cells (PDLSCs) regenerate oral tissue. In vitro expansion causes replicative senescence in stem cells. This causes intracellular reactive oxygen species (ROS) accumulation, which can impair stem cell function. Tissue engineering efficiency is reduced by exogenous ROS stimulation, which causes premature senescence under oxidative stress. Melatonin (MT), a powerful free radical scavenger, can delay PDLSCs senescence but may not maintain stemness under oxidative stress. This experiment examined the effects of hydrogen peroxide-induced oxidative stress on PDLSCs' apoptosis, senescence, and stemness. To determine if MT can reverse the above effects along with the underlying molecular mechanisms involved. PDLSCs were isolated from human premolars and cultured in different conditions. Flow cytometry was used to characterize the cell surface markers of PDLSCs. Hydrogen peroxide was used to induce oxidative stress in PDLSCs. Cell cycle, proliferation, apoptosis, differentiation, ROS, and senescence-associated β-galactosidase activity were assessed by various assays. Reverse transcription-polymerase chain reaction and western blot were used to measure the expression of genes and proteins related to stemness and senescence. MT increases Yes-associated protein expression and maintains cell stemness in an induced inflammatory microenvironment, which may explain its therapeutic effects. We examined how MT affects PDLSCs aging and stemness and its biological mechanisms. Our study reveals MT's role in regulating oxidative stress in PDLSCs and Yes-associated protein-mediated activity, providing insights into cellular functions and new therapeutic targets for tissue regeneration.

Asparagine prevents intestinal stem cell aging via the autophagy-lysosomal pathway.

The age-associated decline in intestinal stem cell (ISC) function is a key factor in intestinal aging in organisms, resulting in impaired intestinal function and increased susceptibility to age-related diseases. Consequently, it is imperative to develop effective therapeutic strategies to prevent ISC aging and functional decline. In this study, we utilized an aging Drosophila model screening of amino acids and found that asparagine (Asn), a nonessential amino acid invivo, exhibits its profound anti-aging properties on ISCs. Asn inhibits the hyperproliferation of aging ISCs in Drosophila, maintains intestinal homeostasis, and extends the lifespan of aging flies. Complementarily, Asn promotes the growth and branching of elderly murine intestinal organoids, indicating its anti-aging capacity to enhance ISC function. Mechanistic analyses have revealed that Asn exerts its effects via the activation of the autophagic signaling pathway. In summary, this study has preliminarily explored the potential supportive role of Asnin ameliorating intestinal aging, providing a foundation for further research into therapeutic interventions targeting age-related intestinal dysfunction.

In situ licensing of mesenchymal stem cell immunomodulatory function via BMP-2 induced developmental process

The immunomodulatory function of mesenchymal stem cells (MSCs) is plastic and susceptible to resident microenvironment in vivo or inflammatory factors in vitro. We propose a unique method to enhance the immunoregulatory functions of mesenchymal stem cells (MSCs) through an artificially controllable in vivo inflammatory microenvironment generated by biomaterials loaded with BMP-2 that induce bone development. MSCs activated through this method effectively induce M1 macrophage polarization toward the M2 phenotype, promote differentiation of naïve T cells into regulatory T cells, and inhibit the proliferation of activated T cells via prostaglandin E2 (PGE2) secretion. This in vivo licensing not only preserves the immunogenicity of MSCs but also alters DNA methylation patterns, enabling MSCs to exhibit immunoregulatory effects with epigenetic memory. Validation in a mouse colitis model demonstrated their therapeutic efficacy and long-term viability. Furthermore, we found that the material composition influences the inflammatory response during development, with polysaccharide-based biomaterials proving advantageous over protein-based materials in establishing an inflammatory niche conducive to MSC activity. These findings underscore the potential of tissue engineering to create in vivo environments that license MSCs, offering a strategic avenue to enhance MSC-based therapies for addressing significant immune disorders.

Engineering ADSCs by manipulating YAP for lymphedema treatment in a mouse tail model.

Secondary lymphedema is a chronic disease associated with deformity of limbs and dysfunction; however, conventional therapies are not curative. Adipose-derived stem cells (ADSCs) based therapy is a promising way, but a single transplantation of ADSCs has limited efficacy. In this study, ADSCs were engineered in vitro and then transplanted into the site of lymphedema. Yes-associated protein (YAP), a crucial regulator of Hippo pathway, plays an important role in regulating stem cell functions. We examined the YAP expression in a mouse tail lymphedema model, and found that transplanted ADSCs exhibited high expression level of YAP and a large number of YAP positive cells existed in lymphedema environment. In vitro, the downregulation of YAP in ADSCs resulted in higher expression levels of genes related to lymphangiogenesis such as Lyve-1, VEGFR-3 and Prox-1. In vivo, YAP-engineered ADSCs generated abundant VEGFR-3-positive lymphatic vessels and significantly improved subcutaneous fibrosis. These results indicated that the transplantation of pre-engineered ADSCs by manipulating YAP is a promising strategy for lymphatic reconstruction.

Microenvironment-optimized gastrodin-functionalized scaffolds orchestrate asymmetric division of recruited stem cells in endogenous bone regeneration

The regeneration of osteoporotic bone defects remains challenging as the critical stem cell function is impaired by inflammatory microenvironment. Synthetic materials that intrinsically direct osteo-differentiation versus self-renewal of recruited stem cell represent a promising alternative strategy for endogenous bone formation. Therefore, a microenvironmentally optimized polyurethane (PU) /n-HA scaffold to enable sustained delivery of gastrodin is engineered to study its effect on the osteogenic fate of stem cells. It exhibited interconnected porous networks and an elevated sequential gastrodin release pattern to match immune-osteo cascade concurrent with progressive degradation of materials. In a critical-sized femur defect model of osteoporotic rat, 5% gastrodin-PU/n-HA potently promoted neo-bone regeneration by facilitating M2 macrophage polarization and CD146+ host stem cell recruitment to defective site. The implantation time-dependently increased the bone marrow mesenchymal stem cell (BMSC) population, and further culture of BMSCs showed a robust ability of proliferation, migration, and mitochondrial resurgence. Of note, some of cell pairs produced one stemness daughter cell while the other committed to osteogenic lineage in an asymmetric cell division (ACD) manner, and a much more compelling ACD response was triggered when 5% gastrodin-PU/n-HA implanted. Further investigation revealed that one-sided concentrated presentation of aPKC and β-catenin in dividing cells effectively induced asymmetric distribution, which polarized aPKC biased the response of the daughter cells to Wnt signal. The asymmetric cell division in skeletal stem cells (SSCs) was mechanically comparable to BMSCs and also governed by distinct aPKC and β-catenin biases. Concomitantly, delayed bone loss adjacent to the implant partly alleviated development of osteoporosis. In conclusion, our findings provide insight into the regulation of macrophage polarization combined with osteogenic commitment of recruited stem cells in an ACD manner, advancing scaffold design strategy for endogenous bone regeneration.Graphical abstract

Identifying colorectal cancer-specific vulnerabilities in the Wnt-driven long non-coding transcriptome

BackgroundAberrant Wnt pathway activation is a key driver of colorectal cancer (CRC) and is essential to sustain tumour growth and progression. Although the downstream protein-coding target genes of the Wnt...

Resveratrol Enhances the Efficacy of Combined BM-MSCs Therapy for Rat Spinal Cord Injury via Modulation of the Sirt-1/NF-κB Signaling Pathway.

Spinal cord injury (SCI) represents a severe trauma to the central nervous system, resulting in significant disability and imposing heavy burdens on families and society. Pathophysiological changes following SCI often trigger secondary injuries that complicate treatment. Bone marrow mesenchymal stem cells (BM-MSCs) have become a focal point of research due to their multifunctionality and self-renewal capabilities; however, their survival and neuroprotective functions are compromised in inflammatory environments. Resveratrol, known for its anti-inflammatory, anti-aging, and anti-oxidative stress properties, has been extensively studied. This research focuses on the anti-inflammatory effects of resveratrol post-SCI and its combined application with BM-MSCs to treat rat spinal cord injuries, exploring both efficacy and mechanisms. In vivo experiments investigated changes in the Sirt-1 signaling pathway post-SCI, while in vitro studies examined the effects of resveratrol on BM-MSCs under inflammatory conditions. The assessment included recovery of motor function, neuronal survival, and apoptosis in SCI rats treated with resveratrol alone or in combination with BM-MSCs. Findings reveal a correlation between Sirt-1 and inflammation signaling pathways post-injury. Resveratrol significantly enhanced the survival and efficacy of BM-MSCs in inflammatory environments by upregulating Sirt-1 and downregulating NF-κB and other inflammatory markers, thereby reducing apoptosis. Combined treatment with resveratrol and BM-MSCs showed superior outcomes in motor function recovery and neuronal survival compared to treatment with BM-MSCs alone. This study offers a novel therapeutic strategy for SCI, enhancing stem cell survival and function through modulation of the Sirt-1/NF-κB pathway, providing a theoretical and experimental foundation for clinical applications.

Drosophila glial system: an approach towards understanding molecular complexity of neurodegenerative diseases.

Glia is pivotal in regulating neuronal stem cell proliferation, functioning, and nervous system homeostasis, significantly influencing neuronal health and disorders. Dysfunction in glial activity is a key factor in the development and progression of brain pathology. However, a deeper understanding of the intricate nature of glial cells and their diverse role in neurological disorders is still required. To this end, we conducted data mining to retrieve literature from PubMed and Google Scholar using the keywords: glia, Drosophila, neurodegeneration, and mammals. The retrieved literature was manually screened and used to comprehensively understand and present the different glial types in Drosophila, i.e., perineurial, subperineurial, cortex, astrocyte-like and ensheathing glia, their relevance with mammalian counterparts, mainly microglia and astrocytes, and their potential to reveal complex neuron-glial molecular networks in managing neurodegenerative processes.

Eccentric Superficial Anterior Lamellar Keratoplasty for Bilateral Limbal Stem Cell Deficiency

Purpose: To describe and report the outcomes of allogeneic eccentric superficial anterior lamellar keratoplasty (SALK), a novel surgical technique, in the management of total bilateral limbal stem cell deficiency (LSCD). Methods: Data were collected retrospectively on all patients with total bilateral LSCD who underwent SALK. Previous surgery, preexisting glaucoma, conjunctivalization, vascularization, lens status, and preoperative best-corrected visual acuity (BCVA) were collected from medical notes. Results: Fifteen eyes underwent eccentric SALK between November 2018 and October 2021. The average age of patients at the time of SALK was 50.3 (SD ± 21.0). There were 4 male and 11 female patients, 9 left eyes and 6 right eyes. The mean difference between pre- and post-BCVA scores were 0.43 LogMAR (95% CI, 0.23–0.63). Ten patients noted an improvement in the features of LSCD with an improvement in BCVA. Five cases were deemed a complete success with a complete resolution of corneal epithelium, no recurrence of LSCD features and an improvement in BCVA. Patients who developed fungal keratitis had poor outcomes. Conclusions: This study describes a new surgical technique of eccentric SALK to treat anterior stromal opacity and restore limbal stem cell function without systemic immunosuppression. The surgery improves the vision in most patients. However, in this complicated patient group, close postsurgical management is vital to recognize complications and intervene with treatment as needed.

Archaeocytes in sponges: simple cells of complicated fate.

Archaeocytes are considered a key cell type in sponges (Porifera). They are believed to be multifunctional cells performing various functions, from nutrient digestion to acting as adult stem cells (ASCs). Thus, archaeocytes are mentioned in discussions on various aspects of sponge biology. As presumed ASCs of an early-diverged animal taxon, archaeocytes are of great fundamental interest for further progress in understanding tissue functioning in metazoans. However, the term 'archaeocyte' is rather ambiguous in its usage and understanding, and debates surrounding archaeocytes have persisted for over a century, reflecting the ongoing complexity of understanding their nature. This article presents a comprehensive revision of the archaeocyte concept, including both its historical development and biological features (i.e. taxonomic distribution, characteristics, and functions). The term 'archaeocyte' and its central aspects were introduced as early as the end of the 19th century based on data mainly from demosponges. Remarkably, despite the general lack of comparative and non-histological data, these early studies already regarded archaeocytes as the ASCs of sponges. These early views were readily inherited by subsequent studies, often without proper verification, shaping views on many aspects of sponge biology for more than a century. Taking into account all available data, we propose considering the archaeocytes as a cell type specific to the class Demospongiae. Clear homologues of archaeocytes are absent in other sponge classes. In demosponges, the term 'archaeocytes' refers to mesohyl cells that have an amoeboid shape, nucleolated nuclei, and non-specific inclusions in the cytoplasm. The absence of specific traits makes the archaeocytes a loosely defined and probably heterogeneous cell population, rendering the exhaustive characterisation of the 'true' archaeocyte population impossible. At the same time, the molecular characterisation of archaeocytes is only beginning to develop. Stemness and almost unlimited potency have always been at the core of the traditional archaeocyte concept. However, currently, the most consistent data on archaeocyte stem cell function come only from developing gemmules of freshwater sponges. For tissues of adult demosponges, the data favour a two-component stem cell system, in which archaeocytes may cooperate with another stem cell population, choanocytes. Simultaneously, cells with archaeocyte morphology function as macrophages in demosponges, participating in the food digestion cycle and immune defence. Such cells should be denoted with the more neutral term 'nucleolar amoebocytes', as the term 'archaeocyte' not only describes the morphology of a cell but also introduces the proposition of its stem nature. Thus, the future usage of the term 'archaeocyte' should be limited to cases where a cell is shown or at least presumed to be a stem cell.

Precision medicine in intestinal ischemia: the emerging role of biomarkers.

Intestinal ischemia (IIs) is a significant gastrointestinal condition characterized by reduced blood flow to the bowel, leading to inflammation and injury. Early diagnosis and management are crucial for preventing severe complications. Under this point of view, circulating biomarkers can enhance patient stratification and guide therapeutic decisions. Fatty acid-binding proteins (FABPs), specifically I-FABP and L-FABP, are small cytosolic proteins released upon enterocyte membrane integrity loss, with elevated plasma levels indicating early intestinal ischemia. Stromal Cell-Derived Factor-1 (SDF-1) regulates stem cell function and shows significantly higher levels in patients with IIs and cardiovascular disease compared to controls. D-Lactate, a bacterial fermentation byproduct, is another significant marker, with higher serum levels observed in intestinal ischemia cases. Alpha-glutathione S-transferase combats intracellular oxidative stress, with significantly elevated levels in acute mesenteric ischemia patients. Additionally, SM22, a small smooth muscle protein, shows higher plasma levels in patients with transmural ischemia compared to those with mucosal ischemic lesions and healthy controls. These biomarkers are promising for their roles in early detection and differentiation of IIs from other gastrointestinal conditions. Therapeutic strategies, including anti-inflammatory therapies, have shown efficacy in managing IIs symptoms and preventing recurrence. This review aims to inform clinicians and researchers about the current advancements in biomarker research and therapeutic approaches for IIs, emphasizing the importance of integrating these biomarkers and treatments into clinical practice to improve the management and prognosis of the disease.

HES1 revitalizes the functionality of aged adipose-derived stem cells by inhibiting the transcription of STAT1.

The effectiveness of adipose-derived stem cells (ADSCs) in therapy diminishes with age. It has been reported that transcription factors (TFs) play a crucial role in the aging and functionality of stem cells. Nevertheless, there is limited understanding regarding the involvement of TFs in the aging mechanism of ADSCs. RNA sequencing (RNA-seq) was utilized to discern the differentially expressed genes in ADSCs obtained from donors of varying ages. TFs exhibiting significant variations across age groups were identified and subsequently validated. ADSCs were manipulated to exhibit either enhanced expression or reduced levels of HES1 and STAT1 via lentivirus transfection and small interfering RNA (siRNA) techniques. The impact of these genetic alterations on ADSCs' proliferation, migration, and cellular senescence was assessed using EdU, transwell, and senescence-activated β-galactosidase (SA-β-gal) staining assays. The DNA sequences bound by HES1 were investigated through the CUT & Tag assay. Lastly, the therapeutic efficacy of aged ADSCs with HES1 overexpression was evaluated in skin injury model of male Sprague-Dawley rats. 678 genes showed differential expression between ADSCs obtained from young and old donors (Y-ADSCs and O-ADSCs), with 47 of these genes being TFs. Notably, the expression of the TF hairy and enhancer of split 1 (HES1) was notably reduced in ADSCs from old donors. Introducing HES1 overexpression in aged ADSCs resulted in improved cellular function and the suppression of cellular senescence, while reducing HES1 levels in young ADSCs had the opposite effect. Mechanistically, HES1 was found to interact with the promoter region of another TF, signal transducer and activator of transcription 1 (STAT1), to inhibit its transcription. Knocking down STAT1 could fully reverse the negative effects caused by decreased HES1 in ADSCs, leading to a reduction in the secretion of pro-inflammatory cytokines such as TNF-α, IL-6, and IL-8. Ultimately, restoring HES1 expression in aged ADSCs demonstrated enhanced therapeutic potential in promoting skin wound healing. HES1 acts as an inhibitor of cellular senescence in the aging progression of ADSCs through the modulation of STAT1 expression, suggesting a promising avenue for rejuvenating senescent ADSCs and improving wound healing.

Harnessing the regenerative effects of human amniotic stem cells (hAFSCs) on restoring erectile function in a bilateral cavernous nerve crush (BCNC) injury rat model.

Intracavernous (IC) injections of stem cells has been shown to ameliorate cavernous nerve (CN)-induced erectile dysfunction (ED). However, the regenerative effects underlying the recovery of erectile function (EF) in human amniotic fluid-derived stem cells (hAFSCs) remain unclear. In the bilateral cavernous nerve crushing (BCNC) injury rat paradigm, we sought to ascertain the effects of hAFSC treatment on EF recovery during the incipient phase. Three groups of 45 male rats were used in this study: sham (Group 1), saline IC injection after BCNC (Group 2), and hAFSC intracavernous injection (ICI) after BCNC (Group 3). hAFSCs from the fourth passage showed potential to differentiate into trilineage cells. All animals were subjected to EF analysis on the 28th day post-injection and tissues were retrieved for histopathological and immunohistochemical analyses. IC injections of hAFSC significantly improved EF parameters in BCNC-ED rats at 28 days post-injury. AFSC treatment enhanced the smooth muscle condition and increased the smooth muscle/collagen ratio, as evidenced by histological analysis. Immunohistology revealed increased expression of 𝛼-SMA andvWf in the corpus cavernosum and enhanced expression of nNOS in the dorsal penile nerve in BCNC-ED rats (p < 0.05). Western blotting showed that hAFSC treatment significantly increased α-SMA expression in the hAFSC group compared with that in the BCNC group. Electron microscopy revealed significantly elevated myelination in the CN (p < 0.05), maintenance of smooth muscle structures, and restoration of EF in BCNC-ED rats treated with hAFSC. hAFSC treatment increased EF in BCNC-ED rats at a single dose. As BCNC-ED resembles ED caused by radical prostatectomy (RP), this therapy has high potential for ED patients after RP surgery.

Lgr5 + intestinal stem cells are required for organoid survival after genotoxic injury.

Progenitors and mature cells can maintain the intestinal epithelium by dedifferentiation and facultative intestinal stem cell (fISC) function when active ISCs (aISCs) are lost to damage. Here, we modeled fISC activation in mouse intestinal organoids with doxorubicin (DXR) treatment, a chemotherapeutic known to ablate Lgr5+ aISCs in vivo. Similar fISC gene activation was observed between organoids treated with low versus high DXR, despite significantly decreased survival at the higher dose. aISCs exhibited dose-dependent loss after DXR treatment but survived at doses compatible with organoid survival. We ablated residual aISCs after DXR treatment using a Lgr52A-DTR allele and observed that aISC survival of the initial genotoxic insult is required for organoid survival following DXR treatment. These results suggest that although typical fISC genes are activated by DXR-induced injury in organoids, functional stemness remains dependent on the aISC pool. Finally, we show that human intestinal organoids require higher doses of DXR to induce loss of survival and downregulation of LGR5. Our data establish a reproducible model of DXR-induced injury in intestinal organoids and reveal differences in in vitro responses to an established in vivo damage modality.

Chronic exposure to polystyrene microplastics triggers osteoporosis by breaking the balance of osteoblast and osteoclast differentiation

Plastic pollution is becoming more and more serious, and microplastics (MPs) formed by degradation from plastics significantly threaten the health of animals and humans. However, it remains unknown how MPs interfere with bone homeostasis by regulating the function of bone marrow mesenchymal stem cells (BMSCs). In order to simulate the toxic impacts of long-term low-dose MPs on the skeletal system, we constructed a 6-month drinking water model of mice exposed to MPs. We found that the bone microstructure in the femur of mice exposed to MPs was destroyed, the quantity of bone trabeculae decreased sharply and the bone mass decreased significantly, accompanied by the decrease of bone formation and the activation of osteoclasts. In addition, RNA sequencing showed NF-κB pathway was activated in MPs-treated BMSCs, manifested as significantly up-regulated inflammatory factors, accelerated the senescence of BMSCs, and inhibited their osteogenic differentiation and extracellular mineralization. Senescent BMSCs induced by MPs led to the overproduction of RANKL, which contributed to the production of more osteoclasts. Importantly, the administration of NF-κB inhibitors in vivo markedly diminished MPs-induced BMSCs senescence and impaired osteogenic differentiation. Meanwhile, the secretion of RANKL caused by MPs was reversed, and osteoclast formation was significantly reduced. In summary, our data innovatively reveal the core mechanism of MPs in bone balance. By promoting the NF-κB signaling pathway, it significantly accelerates the aging of BMSCs, causes a decrease in bone formation, and promotes osteoclast formation through RANKL.

Regulated GATA1 expression as a universal gene therapy for Diamond-Blackfan anemia.

Gene therapy using hematopoietic stem and progenitor cells is altering the therapeutic landscape for patients with hematologic, immunologic, and metabolic disorders but has not yet been successfully developed for individuals with the bone marrow failure syndrome Diamond-Blackfan anemia (DBA). More than 30 mutations cause DBA through impaired ribosome function and lead to inefficient translation of the erythroid master regulator GATA1, providing a potential avenue for therapeutic intervention applicable to all patients with DBA, irrespective of the underlying genotype. Here, we report the development of a clinical-grade lentiviral gene therapy that achieves erythroid lineage-restricted expression of GATA1. We show that this vector is capable of augmenting erythropoiesis in DBA models and diverse patient samples without impacting hematopoietic stem cell function or demonstrating any signs of premalignant clonal expansion. These preclinical safety and efficacy data provide strong support for the first-in-human universal gene therapy trial for DBA through regulated GATA1 expression.

Distinct Essentiality of the Mitochondrial Respiratory Chain in Proliferating Cells in Vivo

Mitochondrial respiratory chain (RC) activity is essential for in vivo cell proliferation, particularly in cancer, CD4+ and CD8+ T cells, and endothelial cells involving ATP production and biosynthesis. The RC is essential for the oxidative tricarboxylic acid (TCA) cycle to produce intermediates that funnel into anabolic pathways to synthesize lipids, proteins, and nucleotides. By contrast, mitochondrial respiration has a distinct role in other proliferating cells including regulatory T cells (Tregs) and stem cells whereby mitochondria are dispensable for in vivo cell proliferation but determine cell fate and function through several signaling mechanisms. In this review, we discuss how the mitochondrial RC is an anabolic engine that supports the proliferation of cancer cells, CD4+ and CD8+ T cells, and endothelial cells while mitochondria serve as central hubs that integrate metabolic signals to control Treg and stem cell fate and function in vivo.