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Background Aim Method Results Conclusion Human umbilical cord mesenchymal stem cells (hUC‐MSCs) have the ability to differentiate into nerve cells, which offers promising options for treating neurodegenerative diseases.To explore the important regulatory molecules of hUC‐MSCs differentiation into neurons.In this research, the neural differentiation of hUC‐MSCs was induced by a low‐serum DMSO/BHA/DMEM medium. The GEO database was used to retrieve the relevant datasets. The starBase and miEAA databases were used for bioinformatics analysis. RT‐qPCR was used to detect the hsa‐miR‐543 level and the mRNA levels of NSE, NeuN, NF‐M, KIF5C, and CALM3. The protein levels of KIF5C and CALM3 were checked by western blotting.The expression levels of NSE, NeuN, NF‐M, KIF5C, and CALM3 were elevated, while hsa‐miR‐543 was under‐expressed in neuro‐induced hUC‐MSCs. The increase in NSE, NeuN, and NF‐M mRNA levels induced by DMSO/BHA/DMEM was partially reversed by the knockdown of KIF5C and CALM3 in hUC‐MSCs. Moreover, the transfection of hsa‐miR‐543 mimic partially countered the DMSO/BHA/DMEM‐induced elevation in NSE, NeuN, NF‐M, KIF5C, and CALM3 mRNA levels.KIF5C and CALM3 facilitated the neuronal differentiation of hUC‐MSCs, whereas hsa‐miR‐543 exerted an opposing effect by negatively regulating KIF5C and CALM3. [ABSTRACT FROM AUTHOR]

Excessive production of reactive oxygen species (ROS) around titanium implants under diabetic conditions causes persistent inflammation, leading to poor osseointegration and even implant failure. Surface modification is an effective way to promote ROS clearance, alleviate inflammation, and stimulate bone formation. In this study, a multifunctional coating is fabricated by introducing cerium (Ce)-containing mesoporous bioactive glass nanoparticles (Ce-MBGNs) onto the titanium surface via an electrophoretic deposition method. The incorporation of Ce-MBGNs remarkably improves surface hydrophilicity by increasing the surface areas. The bioactive ions are appropriately released, thereby promoting mesenchymal stem cell proliferation and differentiation under diabetic conditions. The conversion between Ce(III) and Ce(IV) endows Ce-MBGNs coating with antioxidative nanoenzymes properties to scavenge diabetes-induced ROS, resulting in macrophage polarization towards the anti-inflammatory phenotype. The therapeutic effect of Ce-MBGNs-modified titanium implants is also verified in diabetic rats by inhibiting inflammatory responses and accelerating early osseointegration. Taken together, the findings reveal that the ROS-scavenging and immunomodulation activity of the Ce-MBGNs coating contributes to enhanced osseointegration, and provides a novel implant surface for diabetic patients. [ABSTRACT FROM AUTHOR]

Human bone marrow mesenchymal stem cells (hBMSCs) are adult stem cells residing in the bone marrow, characterized by their capacity for multi-directional differentiation, self-renewal, migration, and engraftment. Serving as seed cells, BMSCs play a pivotal role in the regeneration of bone defects. Hence, investigating the transcription factors and signaling pathways involved in the regulation of osteogenic differentiation in BMSCs holds significant importance. Recent research has unveiled that certain circular RNAs (circRNAs) can function as molecular sponges, influencing the osteogenic differentiation process of mesenchymal stem cells. However, many circRNAs remain undiscovered, and their precise mechanisms remain elusive. Therefore, the objective of this study is to construct an osteogenic differentiation-related circRNA-miRNA-mRNA network in hBMSCs. Subsequently, through bioinformatics analysis, we constructed a ceRNA network related to the osteogenic differentiation ability of hBMSCs, comprising 22 circRNAs, 17 miRNAs, and 15 mRNAs. The potential circRNA-miRNA-mRNA axes, including the role of hsa_circ_0001600 in promoting the osteogenic differentiation of hBMSCs through the targeted regulation of hsa-miR-542-3p, were validated through in vitro experiments. [ABSTRACT FROM AUTHOR]

Interleukin‐4 (IL‐4)/IL‐4 receptor alpha (IL‐4Rα) signalling pathways play important roles in the complex process of bone formation and bone remodelling. However, whether IL‐4/IL‐4Rα participates in skeletogenesis during embryonic development is not completely understood. We used the anti‐IL‐4Rα monoclonal antibody (anti‐IL‐4Rα mAb) as a powerful investigational tool to evaluate the potential roles of IL‐4/IL‐4Rα in the chondrogenic differentiation of rat bone marrow mesenchymal stem cells (BMSCs) in vitro. Simultaneously, we explored the effect of IL‐4/IL‐4Rα on bone ossification during rat embryo‐fetal development. In this study, we found that, compared to the control group, IL‐4 can significantly promote the chondrogenic differentiation of BMSCs. Furthermore, following exposure to anti‐IL‐4Rα mAb in pregnant rats, unexpected phenomena were observed in fetal bone development, including non‐ossification of the fetal sternum, an incomplete ossification centre in long bones and a reduced number of ossification points in digit (toe) bones. To further investigate the underlying mechanism of the phenotype, we studied the rat sternum as the target organ, starting from different time points of sternum development in the embryonic stage. The results indicated that the retardation mainly occurred in the middle and late stages of embryonic development. This retardation was characterized by the inhibition of the differentiation process of mesenchymal stem cells into chondrocytes, resulting in reduced angiogenesis near the ossification centre, failure of osteoblasts to invade the centre of the cartilage body with the blood vessels and delayed formation of the primary ossification centre (POC). Overall, our study demonstrated the significant function of IL‐4/IL‐4Rα in chondrogenic differentiation of BMSCs and bone ossification during embryo‐fetal development. [ABSTRACT FROM AUTHOR]

Maxillary sinus floor lifting surgery is a commonly used surgical method in the field of oral implantology to solve the problem of insufficient vertical bone in the posterior maxillary area. It includes internal and external maxillary sinus lifting. Platelet-rich fibrin (PRF), as a second-generation platelet concentrate, has certain osteoinductive properties and can promote the osteogenic differentiation of mesenchymal stem cells. In maxillary sinus floor lifting surgery, PRF is often mixed with bone grafting materials or used alone, which has great application prospects. Based on current research, the molecular mechanism of PRF promoting osteogenic differentiation of maxillary sinus mucoperiosteal has not been reported in detail, and the application of PRF in maxillary sinus floor lifting surgery is still controversial.This article reviewed the mechanism of PRF in promoting osteogenic differentiation of maxillary sinus mucoperiosteal after maxillary sinus floor lifting surgery, as well as the different application methods of PRF in maxillary sinus floor lifting surgery based on relevant literature, in order to provide a reference for clinicians to rationally use PRF in maxillary sinus floor lifting surgery and furtherly promote the clinical application of PRF. [ABSTRACT FROM AUTHOR]

RNAs and their encoded proteins intricately regulate diverse cell types and states within the human body. Dysregulated RNA expressions or mutations can lead to various diseased cell states, including tumorigenesis. Detecting and manipulating these endogenous RNAs offers significant promise for restoring healthy cell states and targeting tumors both in research and clinical contexts. This study presents an RNA-IN and RNA-OUT genetic circuit capable dynamically sensing and manipulating any RNA target in a programmable manner. The RNA-IN module employes a programmable CRISPR-associated protease (CASP) complex for RNA detection, while the RNA-OUT module utilizes an engineered protease-responsive dCas9-VPR activator. Additionally, the CASP module can detect point mutations by harnessing an uncovered dual-nucleotide synergistic switching effect within the CASP complex, resulting in the amplification of point-mutation signals from initially undetectable levels (1.5-fold) to a remarkable 94-fold. We successfully showcase the circuit's ability to rewire endogenous RNA-IN signals to activate endogenous progesterone biosynthesis pathway, dynamically monitor adipogenic differentiation of mesenchymal stem cells (MSCs) and the epithelial-to-mesenchmal trans-differentiation, as well as selective killing of tumor cells. The programmable RNA-IN and RNA-OUT circuit exhibits tremendous potential for applications in gene therapy, biosensing and design of synthetic regulatory networks. RNAs and their encoded proteins intricately regulate diverse cell types and states within the human body. Here the authors report an RNA-IN/OUT genetic circuit to sense and respond any endogenous RNA with single-nucleotide resolution allowing them to dynamically monitor stem cell differentiations, and rewire regulatory networks in mammals. [ABSTRACT FROM AUTHOR]

Objective: In this study we have focused on biocompatibility and osteoinductive capacity analysis of self-manufactured single-phase (HAP) and two-phase (HAP and β-ТСР) bioactive ceramics with various chemical modifications (Fig. 1). Results: We demonstrate a reduction in solubility for all analyzed composite after the treatment with H2O and H2O2, accompanied by an enhancement in adsorption activity. This modification also resulted in an increase in micro- and macroporosity, along with a rise in the open porosity. Adipose-derived mesenchymal stromal cells demonstrated excellent cell adhesion and survival when cultured with these ceramics. Calcium phosphate ceramics (H-500, HT-500, and HT-1 series) stimulated alkaline phosphatase expression, promoted calcium deposition, and enhanced osteopontin expression in ADSCs, independently inducing osteogenesis without additional osteogenic stimuli. These findings underscore the promising potential of HAP-based bioceramics for bone regeneration/reconstruction. [ABSTRACT FROM AUTHOR]

Bone is a dynamic tissue that is constantly remodeled throughout adult life. Recently, it has been shown that bone turnover decreases shortly after food consumption. This process has been linked to the fermentation of non-digestible food ingredients such as inulin by gut microbes, which results in the production of the short-chain fatty acids (SCFAs) acetate, propionate and butyrate. SCFAs exert various metabolic functions, which in part can be explained by activation of G protein-coupled receptors (Gpr) 41 and 43. However, the potential relevance of a SCFA-Gpr41/43 signaling axis for bone metabolism has not been established. The aim of our study is to investigate the role of Gpr41/43 in bone metabolism and osteogenic differentiation of mesenchymal stem cells. For this purpose, we analyzed the skeletal phenotype of wild type controls (WT) and Gpr41/43 double knockout (Gpr41/43 dKO) mice fed either a chow or an inulin-enriched diet. In addition, we isolated bone marrow derived mesenchymal stem cells from WT and Gpr41/43 dKO mice and differentiated them into osteoblasts in the absence or presence of acetate. MicroCT scanning of femoral bones of Gpr41/43 dKO mice revealed a significant increase of trabecular bone volume and trabecular compared to WT controls. Treatment of WT bone marrow-derived osteoblasts with acetate resulted in decreased mineralization and substantial downregulation of bone formation markers such as Phex, Ptgs2 and Col1a1. Notably, this effect was strongly attenuated in differentiated osteoblasts lacking Gpr41/43. Inversely, acetate supplementation resulted in higher levels of adipocyte marker genes including Pparg, Lpl and Adipoq in bone marrow-derived cells from WT mice, an effect blunted in differentiated cells isolated from Gpr41/43 dKO mice. Overall, these data indicate that acetate regulates bone architecture via SCFA-Gpr41/43 signaling by modulating the osteogenic versus adipogenic differentiation of mesenchymal stem cells. [ABSTRACT FROM AUTHOR]

Bone fractures are one of the most common types of human injury. This study aimed to create a synergistic action of polymeric films (PFs) based on polycaprolactone (PCL) and polyethylene glycol (PEG) (PCL‐PEG‐PFs) deposited by casting, combined with mesenchymal stem cells (MSCs) that differentiate into osteoblasts for bone regeneration. In vitro experiments indicated that the PCL‐PEG‐PFs (70:30) exhibited low cytotoxicity and enhanced cell adhesion capacity. In vivo studies were performed to evaluate the bone regeneration capacity of PFs with MSCs that adhered to and differentiated into osteoblasts. The cell differentiation process was carried out for 18 days in cell culture for subsequent implantation in the calvaria of male C57BL/6J mice, which remained in contact with the bone lesion for another 14 days. In vivo studies indicated that the application of PCL‐PEG‐PFs (70:30) increased the bone surface area to the total volume, with significant regeneration areas (levels greater than 25%) and interconnectivity compared to the control. In addition, the generated tissue presented cells with a morphology comparable to that of the peripheral tissue of the injured region, indicating a positive synergistic interaction between PCL‐PEG‐PFs (70:30) and MSCs differentiated into osteoblasts in contact with the bone lesion. [ABSTRACT FROM AUTHOR]

Traumatic heterotopic ossification is a condition in which extraskeletal bone formation occurs in soft tissues after injury. It most commonly occurs in patients who had major orthopedic surgery and in those with severe extremity injuries. The lesion causes local pain and can impair motor function of the affected limb, but there is currently no established prophylaxis or treatment for this condition. In this study, we show that immobilization at an early stage of the inflammatory response after injury can attenuate ossification formation in a murine Achilles tenotomy model. Gene expression analysis revealed a decrease in the expression of Tnf and an increase in the expression of Mkx, which encodes one of the master regulators of tendon differentiation, Mohawk. Notably, we found that TNF‐α suppressed the expression of Mkx transcripts and accelerated the osteogenic differentiation of tendon‐derived mesenchymal stem cells (MSCs), suggesting that TNF‐α acts as a negative regulator of Mkx transcription. Consistent with these findings, pharmaceutical inhibition of TNF‐α increased the expression of Mkx transcripts and suppressed bone formation in this mouse model. These findings reveal the previously unrecognized involvement of TNF‐α in regulating tendon MSC fate through suppression of Mkx expression and suggest that TNF‐α is a potential target for preventing traumatic heterotopic ossification. [ABSTRACT FROM AUTHOR]

Background: The prevention and treatment of bone loss and osteoporotic fractures is a public health challenge. Combined with normobaric hypoxia, whole-body vibration has a high clinic potential in bone health and body composition. The effect of this therapy may be mediated by its action on bone marrow mesenchymal stem cells (MSCs). Objectives: Evaluate the effects of cyclic low-vibration stimuli and/or hypoxia on bone marrow-derived human MSC differentiation. Methods: MSCs were exposed four days per week, two hours/day, to hypoxia (3% O2) and/or vibration before they were induced to differentiate or during differentiation into osteoblasts or adipocytes. Gene and protein expression of osteoblastic, adipogenic, and cytoskeletal markers were studied, as well as extracellular matrix mineralization and lipid accumulation. Results: early osteoblastic markers increased in undifferentiated MSCs, pretreated in hypoxia and vibration. This pretreatment also increased mRNA levels of osteoblastic genes and beta-catenin protein in the early stages of differentiation into osteoblasts without increasing mineralization. When MSCs were exposed to vibration under hypoxia or normoxia during osteoblastic differentiation, mineralization increased with respect to cultures without vibrational stimuli. In MSCs differentiated into adipocytes, both in those pretreated as well as exposed to different conditions during differentiation, lipid formation decreased. Changes in adipogenic gene expression and increased beta-catenin protein were observed in cultures treated during differentiation. Conclusions: Exposure to cyclic hypoxia in combination with low-intensity vibratory stimuli had positive effects on osteoblastic differentiation and negative ones on adipogenesis of bone marrow-derived MSCs. These results suggest that in elderly or frail people with difficulty performing physical activity, exposure to normobaric cyclic hypoxia and low-density vibratory stimuli could improve bone metabolism and health. [ABSTRACT FROM AUTHOR]

The stem cell niche in the bone marrow is a hypoxic environment, where the low oxygen tension preserves the pluripotency of stem cells. We have identified mesangiogenic progenitor cells (MPC) exhibiting angiogenic and mesenchymal differentiation capabilities in vitro. The effect of hypoxia on MPC has not been previously explored. In this study, MPCs were isolated from volunteers' bone marrow and cultured under both normoxic and hypoxic conditions (3% O2). MPCs maintained their characteristic morphology and surface marker expression (CD18 + CD31 + CD90-CD73-) under hypoxia. However, hypoxic conditions led to reduced MPC proliferation in primary cultures and hindered their differentiation into mesenchymal stem cells (MSCs) upon exposure to differentiative medium. First passage MSCs derived from MPC appeared unaffected by hypoxia, exhibiting no discernible differences in proliferative potential or cell cycle. However, hypoxia impeded the subsequent osteogenic differentiation of MSCs, as evidenced by decreased hydroxyapatite deposition. Conversely, hypoxia did not impact the angiogenic differentiation potential of MPCs, as demonstrated by spheroid-based assays revealing comparable angiogenic sprouting and tube-like formation capabilities under both hypoxic and normoxic conditions. These findings indicate that hypoxia preserves the stemness phenotype of MPCs, inhibits their differentiation into MSCs, and hampers their osteogenic maturation while leaving their angiogenic potential unaffected. Our study sheds light on the intricate effects of hypoxia on bone marrow-derived MPCs and their differentiation pathways. [ABSTRACT FROM AUTHOR]

The extracellular microenvironment encompasses the extracellular matrix, neighbouring cells, cytokines, and fluid components. Anomalies in the microenvironment can trigger aging and a decreased differentiation capacity in mesenchymal stem cells (MSCs). MSCs can perceive variations in the firmness of the extracellular matrix and respond by regulating mitochondrial function. Diminished mitochondrial function is intricately linked to cellular aging, and studies have shown that mitochondria‐lysosome contacts (M‐L contacts) can regulate mitochondrial function to sustain cellular equilibrium. Nonetheless, the influence of M‐L contacts on MSC aging under varying matrix stiffness remains unclear. In this study, utilizing single‐cell RNA sequencing and atomic force microscopy, we further demonstrate that reduced matrix stiffness in older individuals leads to MSC aging and subsequent decline in osteogenic ability. Mechanistically, augmented M‐L contacts under low matrix stiffness exacerbate MSC aging by escalating mitochondrial oxidative stress and peripheral division. Moreover, under soft matrix stiffness, cytoskeleton reorganization facilitates rapid movement of lysosomes. The M‐L contacts inhibitor ML282 ameliorates MSC aging by reinstating mitochondrial network and function. Overall, our findings confirm that MSC aging is instigated by disruption of the mitochondrial network and function induced by matrix stiffness, while also elucidating the potential mechanism by which M‐L Contact regulates mitochondrial homeostasis. Crucially, this presents promise for cellular anti‐aging strategies centred on mitochondria, particularly in the realm of stem cell therapy. [ABSTRACT FROM AUTHOR]

Sphingosine-1-phosphate (S1P) exhibits receptor-mediated physiological effects by facilitating the differentiation of mesenchymal stem cells toward the osteoblast lineage. This study aimed to determine the effect of S1P on odontogenic differentiation of mouse immortalized stem cells of dental apical papilla (iSCAP) and assess the distribution of the S1P receptor 1 (S1PR1) in the apical papilla and the root canal wall of immature rat molars. Immunostaining for S1PR1 was conducted at the apex of the rat mandibular first molar and within the root canal wall. The iSCAP was treated with S1P and bone morphogenetic protein (BMP)-9 (for comparison), and the expression levels of the odontogenic differentiation marker were evaluated via real-time reverse-transcriptase quantitative polymerase chain reaction and enzyme-linked immunosorbent assay. Mineralization and lipid droplet formation were evaluated via Alizarin red and Oil red O staining. S1PR1-positive cells were expressed in areas of both apical papilla and dentin-pulp interface of root canal wall. During the odontogenic differentiation of iSCAP, S1P and BMP-9 increased the expression of the differentiation marker mRNA and secreted proteins including dentin sialophosphoprotein, dentin matrix phosphoprotein 1, and matrix extracellular phosphoglycoprotein. The S1PR1 signaling pathway is involved in the action of S1P, but not that of BMP-9. S1PR1 signaling also facilitated mineralization in iSCAP and suppressed the differentiation of these cells into adipocytes. S1P induced odontogenic differentiation of iSCAP through S1PR1. Furthermore, S1PR1-positive cells were expressed in the apical papilla of immature rat molars and in the dentin-pulp interface where odontoblast-like cells exist. [ABSTRACT FROM AUTHOR]

ABSTRACT Objectives Materials and Methods Results Conclusion Dental pulp stem cells (DPSCs) have been extensively used for tissue regeneration owing to their notable capabilities. Insulin‐like growth factor‐binding protein 5 (IGFBP5) regulates osteogenic differentiation of mesenchymal stem cells (MSCs); however, the underlying regulatory mechanisms require further investigation.Carboxyfluorescein succinimidyl ester, an alkaline phosphatase (ALP) activity assay and Alizarin Red staining were used to reveal the role of IGFBP5 in DPSCs. Protein expression levels were determined using western blotting. Immunofluorescence was used to observe cell sub‐localisation. Subcutaneous transplantation in nude mice was used to observe the osteogenesis of DPSCs in vivo.IGFBP5 enhanced the proliferation and osteogenic differentiation of DPSCs. Deletion of the nuclear localisation sequence (NLS) of IGFBP5 prevented its nuclear import and abolished all its promoting effects on DPSCs; ivermectin stimulation attenuated the enhancement of ALP activity by IGBFP5. Bone‐like tissue formation promoted by IGFBP5 in vivo vanishes when the NLS is deleted. Inhibition of IGFBP5 nuclear import attenuated the IGFBP5‐induced phosphorylation of JNK (p‐JNK) and phosphorylated ERK (p‐ERK) in DPSCs.Our findings suggest that cell proliferation and osteogenic differentiation effects exerted by IGFBP5 on DPSCs are closely associated with their entry into the nucleus, thereby providing a novel potential target for tissue regeneration. [ABSTRACT FROM AUTHOR]

Cryopreservation is essential for the broad clinical application of mesenchymal stem cells (MSCs), yet its impact on their cellular characteristics and cardiomyogenic differentiation potential remains a critical concern in translational medicine. This study aimed to evaluate the effects of cryopreservation on the biological properties and cardiomyogenic capacity of rat adipose-derived MSCs (AD-MSCs). We examined their cellular morphology, surface marker expression (CD29, CD90, CD45), trilineage differentiation potential (adipogenic, osteogenic, chondrogenic), and gene expression profiles for the pluripotency marker REX1 and immunomodulatory markers TGFβ1 and IL-6. After inducing cardiomyocyte differentiation, we assessed cardiac-specific gene expressions (Troponin I, MEF2c, GSK-3β) using quantitative RT-qPCR, along with live/dead cell staining and immunofluorescence for cardiac-specific proteins (Troponin T, α-actinin, Myosin Heavy Chain). Cryopreserved AD-MSCs preserved their morphology, surface markers, and differentiation potential, but exhibited a reduced expression of REX1, TGFβ1, and IL-6. Additionally, cryopreservation diminished cardiomyogenic differentiation, as indicated by the lower levels of Troponin I, MEF2c, and GSK-3β seen compared to non-cryopreserved cells. Despite this, high cell viability (>90%) and maintained cardiac protein expression were observed post-cryopreservation. These findings highlight the necessity of optimizing cryopreservation protocols to ensure the full therapeutic potential of AD-MSCs, particularly in applications related to cardiac regenerative medicine. [ABSTRACT FROM AUTHOR]

The global diffusion of antibiotic resistance poses a severe threat to public health. Addressing antibiotic-resistant infections requires innovative approaches, such as antibacterial nanostructured surfaces (ANSs). These surfaces, featuring ordered arrays of nanostructures, exhibit the ability to kill bacteria upon contact. However, most currently developed ANSs utilize bioinert materials, lacking bioactivity crucial for promoting tissue regeneration, particularly in the context of bone infections. This study introduces ANSs composed of bioactive calcium phosphate nanocrystals. Two distinct ANSs were created through a biomineralization-inspired growth of amorphous calcium phosphate (ACP) precursors. The ANSs demonstrated efficient antibacterial properties against both Gram-negative (P. aeruginosa) and Gram-positive (S. aureus) antibiotic resistant bacteria, with up to 75 % mortality in adhered bacteria after only 4 h of contact. Notably, the ANS featuring thinner and less oriented nano-needles exhibited superior efficacy attributed to simultaneous membrane rupturing and oxidative stress induction. Moreover, the ANSs facilitate the proliferation of mammalian cells, enhancing adhesion, spreading, and reducing oxidative stress. The ANSs displayed also significant bioactivity towards human mesenchymal stem cells, promoting colonization and inducing osteogenic differentiation. Specifically, the ANS with thicker and more ordered nano-needles demonstrated heightened effects. In conclusion, ANSs introduced in this work have the potential to serve as foundation for developing bone graft materials capable of eradicate site infections while concurrently stimulating bone regeneration. Nanostructured surfaces with antibacterial properties through a mechano-bactericidal mechanism have shown significant potential in fighting antibiotic resistance. However, these surfaces have not been fabricated with bioactive materials necessary for developing devices that are both antibacterial and able to stimulate tissue regeneration. This study demonstrates the feasibility of creating nanostructured surfaces of ordered calcium phosphate nano-needles through a biomineralization-inspired growth. These surfaces exhibit dual functionality, serving as effective bactericidal agents against Gram-negative and Gram-positive antibiotic-resistant bacteria while also promoting the proliferation of mammalian cells and inducing osteogenic differentiation of human mesenchymal stem cells. Consequently, this approach holds promise in the context of bone infections, introducing innovative nanostructured surfaces that could be utilized in the development of antimicrobial and osteogenic grafts. [Display omitted] [ABSTRACT FROM AUTHOR]

Stimulating erythropoiesis is essential in the treatment of various types of anemia. Sheng Xue Ning (SXN) is commonly used in China as an iron supplement to treat iron deficiency anemia, renal anemia, and anemia in pregnancy. This research reports a novel effect of SXN in enhancing the proliferation of hematopoietic stem/progenitor cell (HSPC) to promote erythropoiesis in the bone marrow, which is distinct from conventional iron supplements that primarily aid in the maturation of red blood cells. Employing a model of hematopoietic dysfunction induced by X-ray exposure, we evaluated the efficacy of SXN in restoring hematopoietic function. SXN significantly promoted the recovery of peripheral erythroid cells and enhanced the proliferation and differentiation of Lin−/c-KIT+/Sca-1+ HSPC in mice exposed to X-ray irradiation. Our results showed that SXN elevated the expression of stem cell factor (SCF) and activated the SCF/c-KIT/PI3K/AKT signaling pathway, facilitating the proliferation and differentiation of HSPC. In vitro, SXN markedly enhanced the proliferation of bone marrow nucleated cell (BMNC) and the colony-forming capacity of BFU-E, CFU-E, and CFU-GM, while also elevating the expression of proteins involved in the SCF/c-KIT/PI3K/AKT pathway in BMNC. Additionally, SXN enhanced the proliferation and differentiation of mesenchymal stem cell (MSC) and increased SCF secretion. In conclusion, SXN demonstrates the capacity to enhance erythropoiesis by upregulating SCF expression, thereby promoting HSPC proliferation and differentiation via the SCF/c-KIT/PI3K/AKT pathway. SXN may offer a new strategy for improving the activity of HSPC and promoting erythropoiesis in the treatment of hematopoiesis disorders. [ABSTRACT FROM AUTHOR]

Osteoporosis and other degenerative bone diseases pose significant challenges to global healthcare systems due to their prevalence and impact on quality of life. Current treatments often alleviate symptoms without fully restoring damaged bone tissue, highlighting the need for innovative approaches like stem cell therapy. Adipose-derived mesenchymal stem cells (ADMSCs) are particularly promising due to their accessibility, abundant supply, and strong differentiation potential. However, ADMSCs tend to favor adipogenic pathways, necessitating the use of differentiation inducers (DIs), three-dimensional (3D) hydrogel environments, and photobiomodulation (PBM) to achieve targeted osteogenic differentiation. This study investigated the combined effects of osteogenic DIs, a fast-dextran hydrogel matrix, and PBM at specific wavelengths and fluences on the proliferation and differentiation of immortalized ADMSCs into osteoblasts. Near-infrared (NIR) and green (G) light, as well as their combination, were used with fluences of 3 J/cm2, 5 J/cm2, and 7 J/cm2. The results showed statistically significant increases in alkaline phosphatase levels, a marker of osteogenic differentiation, with G light at 7 J/cm2 demonstrating the most substantial impact on ADMSC differentiation. Calcium deposits, visualized by Alizarin red S staining, appeared as early as 24 h post-treatment in PBM groups, suggesting accelerated osteogenic differentiation. ATP luminescence assays indicated increased proliferation in all experimental groups, particularly with NIR and NIR-G light at 3 J/cm2 and 5 J/cm2. MTT viability and LDH membrane permeability assays confirmed enhanced cell viability and stable cell health, respectively. In conclusion, PBM significantly influences the differentiation and proliferation of hydrogel-embedded immortalized ADMSCs into osteoblast-like cells, with G light at 7 J/cm2 being particularly effective. These findings support the combined use of 3D hydrogel matrices and PBM as a promising approach in regenerative medicine, potentially leading to innovative treatments for degenerative bone diseases. [ABSTRACT FROM AUTHOR]

The study aimed to develop a biodegradable scaffold incorporating valproic acid (VPA) for improved human bone marrow-derived mesenchymal stem cell (hBMSC) proliferation, differentiation, and bone mineral synthesis. A chitosan–gelatin (CH-G) scaffold was fabricated and loaded with varying concentrations of VPA (1, 3, 5 mM/L). In vitro studies assessed drug release, cell proliferation, morphology, mineralization, and gene expression. VPA was rapidly released from the scaffold, with over 90% cumulative release within seven days. Cells cultured on VPA-loaded scaffolds exhibited significantly enhanced proliferation and mineralization compared to the control. VPA treatment upregulated osteocalcin and runt-related transcription factor 2 (Runx-2) expression, key markers of osteogenic differentiation. The CH-G scaffold, particularly with 1 mM/L VPA, demonstrates excellent biocompatibility and promotes hBMSC-mediated bone regeneration. This novel approach holds promise for future applications in bone tissue engineering. [ABSTRACT FROM AUTHOR]

Developing strategies to enhance cartilage differentiation in mesenchymal stem cells and preserve the extracellular matrix is crucial for successful cartilage tissue reconstruction. Hypoxia‐inducible factor‐1α (HIF‐1α) plays a pivotal role in maintaining the extracellular matrix and chondrocyte phenotype, thus serving as a key regulator in chondral tissue engineering strategies. Recent studies have shown that Ubiquitin C‐terminal hydrolase L1 (UCHL1) is involved in the deubiquitylation of HIF‐1α. However, the regulatory role of UCHL1 in chondrogenic differentiation has not been investigated. In the present study, we initially validated the promotive effect of UCHL1 expression on chondrogenesis in adipose‐derived stem cells (ADSCs). Subsequently, a hybrid baculovirus system was designed and employed to utilize three CRISPR activation (CRISPRa) systems, employing dead Cas9 (dCas9) from three distinct bacterial sources to target UCHL1. Then UCHL1 and HIF‐1α inhibitor and siRNA targeting SRY‐box transcription factor 9 (SOX9) were used to block UCHL1, HIF‐1α and SOX9, respectively. Cartilage differentiation and chondrogenesis were measured by qRT‐PCR, immunofluorescence and histological staining. We observed that the CRISPRa system derived from Staphylococcus aureus exhibited superior efficiency in activating UCHL1 compared to the commonly used the CRISPRa system derived from Streptococcus pyogenes. Furthermore, the duration of activation was extended by utilizing the Cre/loxP‐based hybrid baculovirus. Moreover, our findings show that UCHL1 enhances SOX9 expression by regulating the stability and localization of HIF‐1α, which promotes cartilage production in ADSCs. These findings suggest that activating UCHL1 using the CRISPRa system holds significant potential for applications in cartilage regeneration. [ABSTRACT FROM AUTHOR]

Heterotopic ossification is abnormal bone formation in soft tissues that occurs primarily after injury and major surgery. This condition often causes local pain and limits joint motion in the affected limb. Currently, there is no effective treatment or prophylaxis for this condition other than surgical removal of the lesion. Recent studies suggest that retinoic acid receptor (RAR) agonists are effective in suppressing heterotopic ossification in patients with Fibrodysplasia Ossificans Progressiva, a congenital disorder characterized by progressive ossification of soft tissue, by suppressing the aberrant differentiation of mesenchymal stem cells in muscle. In this study, we aimed to elucidate the potential use of RAR agonists in suppressing injury‐induced ectopic tendon ossification using a mouse Achilles tenotomy model. Contrary to our initial hypothesis, administration of RAR agonists throughout the experimental period (5 weeks) accelerated ectopic tendon ossification in our model. Of note, in vitro differentiation experiments using tendon‐derived mesenchymal stem cells revealed that RAR agonists play opposing roles in osteogenic and chondrogenic differentiation, promoting the former and suppressing the latter. Indeed, we found that RAR agonists suppressed tendon ossification when administered before cartilage nodule formation, but promoted it when administered after. These results suggest that RAR agonists have a dual and opposing effect on tendon ectopic ossification, depending on the duration and timing of their administration. Our data may provide a basis for further investigation of the potential use of RAR agonists in the treatment of injury‐induced heterotopic ossification. [ABSTRACT FROM AUTHOR]

Background. Adipogenic differentiation stands as a crucial pathway in the range of differentiation options for mesenchymal stem cells (MSCs), carrying significant importance in the fields of regenerative medicine and the treatment of conditions such as obesity and osteoporosis. However, the exact mechanisms that control the adipogenic differentiation of MSCs are not yet fully understood. Materials and Methods. We procured datasets, namely GSE36923, GSE80614, GSE107789, and GSE113253, from the Gene Expression Omnibus database. These datasets enabled us to perform a systematic analysis, including the identification of differentially expressed genes (DEGs) pre‐ and postadipogenic differentiation in MSCs. Subsequently, we conducted an exhaustive analysis of DEGs common to all four datasets. To gain further insights, we subjected these overlapped DEGs to comprehensive gene ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway analyses. Following the construction of protein–protein interaction (PPI) networks, we meticulously identified a cohort of hub genes pivotal to the adipogenic differentiation process and validated them using real‐time quantitative polymerase chain reaction. Subsequently, we ventured into the construction of miRNA‐gene and TF–gene interaction networks. Results. Our rigorous analysis revealed a total of 18 upregulated DEGs and 12 downregulated DEGs that consistently appeared across all four datasets. Notably, the peroxisome proliferator‐activated receptor signaling pathway, regulation of lipolysis in adipocytes, and the adipocytokine signaling pathway emerged as the top‐ranking pathways significantly implicated in the regulation of these DEGs. Subsequent to the construction of the PPI network, we identified and validated 10 key node genes, namely IL6, FABP4, ADIPOQ, LPL, PLIN1, RBP4, ACACB, NT5E, KRT19, and G0S2. Our endeavor to construct miRNA–gene interaction networks led to the discovery of the top 10 pivotal miRNAs, including hsa‐mir‐27a‐3p, hsa‐let‐7b‐5p, hsa‐mir‐1‐3p, hsa‐mir‐124‐3p, hsa‐mir‐155‐5p, hsa‐mir‐16‐5p, hsa‐mir‐101‐3p, hsa‐mir‐21‐3p, hsa‐mir‐146a‐5p, and hsa‐mir‐148b‐3p. Furthermore, the construction of TF–gene interaction networks revealed the top 10 critical TFs: ZNF501, ZNF512, YY1, EZH2, ZFP37, ZNF2, SOX13, MXD3, ELF3, and TFDP1. Conclusions. In summary, our comprehensive study has successfully unraveled the pivotal hub genes that govern the adipogenesis of MSCs. Moreover, the meticulously constructed miRNA‐gene and TF–gene interaction networks are poised to significantly augment our comprehension of the intricacies underlying MSC adipogenic differentiation, thus providing a robust foundation for future advances in regenerative biology. [ABSTRACT FROM AUTHOR]

Osteoarthritis is a prevalent joint disease affecting both humans and animals. It is characterized by articular cartilage degeneration and joint surface eburnation. Currently, no effective pharmacological treatment is available to restore the original function and structure of defective cartilage.This study explores the potential of stem cell-based therapy in treating joint diseases involving cartilage degeneration, offering a promising avenue for future research and treatment. The primary aim was to compare the characteristics and, more importantly, the chondrogenic differentiation potential of human and rat adipose-derived mesenchymal stem cells (AD-MSCs).Rat adipose tissue was collected from Sprague Dawley rats, while human adipose tissue was obtained in the form of lipoaspirate. The mesenchymal stem cells (MSCs) were then harvested using collagenase enzyme and subcultured. We meticulously evaluated and compared the cell morphology, percentage of cell viability, population doubling time, metabolic proliferation, and chondrogenic differentiation potential of MSCs harvested from both sources. Chondrogenic differentiation was induced at passage 3 using the 3D pellet culture method and assessed through histological and molecular analysis.The findings revealed that human and rat AD-MSCs were phenotypically identical, and an insignificant difference was found in cell morphology, percentage of cell viability, metabolic proliferation, and population doubling time. However, the chondrogenic differentiation potential of human AD-MSCs was evaluated as significantly higher than that of rat AD-MSCs.The current study suggests that research regarding chondrogenic differentiation of rat AD-MSCs can be effectively translated to humans. This discovery is a significant contribution to the field of regenerative medicine and has the potential to advance our understanding of stem cell-based therapy for joint diseases. [ABSTRACT FROM AUTHOR]

Mesenchymal stem cells (MSCs) are a type of pluripotent adult stem cell with strong self-renewal and multi-differentiation abilities. Their excellent biological traits, minimal immunogenicity, and abundant availability have made them the perfect seed cells for treating a wide range of diseases. After more than 60 years of clinical practice, metformin is currently one of the most commonly used hypoglycaemic drugs for type 2 diabetes in clinical practice. In addition, metformin has shown great potential in the treatment of various systemic diseases except for type 2 diabetes in recent years, and the mechanisms are involved with antioxidant stress, anti-inflammatory, and induced autophagy, etc. This article reviews the effects and the underlying mechanisms of metformin on the biological properties, including proliferation, multi-differentiation, and aging, of MSCs in vitro and in vivo with the aim of providing theoretical support for indepth scientific research and clinical applications in MSCs-mediated disease treatment. [ABSTRACT FROM AUTHOR]

AbstractGraphene oxide (GO) is widely used in bone tissue engineering due to its good biocompatibility and proliferation, and is often used in combination with other hydrogels, which not only reduces the cytotoxicity of GO but also improves the mechanical properties of the hydrogels. We developed injectable carboxymethyl chitosan (CMC)/hydroxyethyl cellulose (HEC)/β-tricalcium phosphate (β-TCP)/GO hydrogel via hydrogen bonding cross-linked between (CMC) and (HEC), also, calcium cross-linked by β-TCP was also involved to further improvement of mechanical properties of the hydrogel, and incorporate different concentration of GO in these hydrogel systems. The characterization of the novel hydrogel was tested by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). The swelling ratio and mechanical properties were investigated, the results showed that the addition of GO was able to reduce the swelling rate of hydrogels and improve their mechanical properties, with the best effect in the case of 1 mg/mL content. In vivo experimental studies showed that the hydrogel significantly promoted the osteogenic differentiation of rat bone marrow mesenchymal stem cells (rBMSCs), with the best effect at a concentration of 2 mg/mL. The results of the cellular experiments were similar. Therefore, the novel environment-friendly and non-toxic injectable CMC/HEC/β-TCP/GO hydrogel system may have potential applications in bone tissue engineering. [ABSTRACT FROM AUTHOR]

Research question: Theca interna cells (TICs) are an indispensable cell source for ovarian follicle development and steroidogenesis. Recent studies have identified theca stem cells (TSCs) in both humans and animals. Interestingly, TSCs express mesenchymal stem cell (MSC)-related markers and can differentiate into mesenchymal lineages. MSCs are promising for tissue engineering and regenerative medicine due to their self-renewal and differentiation abilities. Therefore, this study investigated the potential origin of TICs from MSCs. Design: Whole ovaries from postmenopausal organ donors were obtained, and their cortex was cryopreserved prior to the isolation of stromal cells. These isolated cells were differentiated in vitro to TICs using cell media enriched with various growth factors and hormones. Immunocytochemistry, an enzyme-linked immunosorbent assay, flow cytometry, and reverse transcription–quantitative polymerase chain were employed at different timepoints. Data were analyzed using one-way ANOVA. Results: Immunocytochemistry showed an increase in TIC markers from day 0 to day 8 and a significant rise in MSC-like markers on day 2. This corresponds with rising androstenedione levels from day 2 to day 13. Flow cytometry identified a decreasing MSC-like cell population from day 2 onwards. The CD13+ cell population and its gene expression increased significantly over time. NGFR and PDGFRA expression was induced on days 0 and 2, respectively, compared to day 13. Conclusions: This study offers insights into MSC-like cells as the potential origin of TICs. Differentiating TICs from these widely accessible MSCs holds potential significance for toxicity studies and investigating TIC-related disorders like polycystic ovary syndrome (PCOS). [ABSTRACT FROM AUTHOR]

Tissue engineering integrating cell-based approaches is promising for urinary tract injury treatments. Exploring the Impact of Nanostructured Heparin Conjugated-Polycaprolactone (HPCL) on the differentiation of Adipose Mesenchymal Stem Cells (ADMSCs) into Smooth Muscle Cells (SMCs). PCL nanofibers were produced by electrospinning and conjugated with heparin. The surface properties of the scaffolds were analyzed using FE-SEM for imaging, FTIR for investigation of chemical structure, assessments of surface roughness, thermomechanical characteristics, and the contact angle to evaluate wettability. The study included six groups; Group I: ADMSCs cells, Group II: ADMSCs seeded on PCL, Group III: ADMSCs seeded on HPCL, Group IV: SMCs cells, Group V: SMCs seeded on PCL, and Group VI: MSCs seeded on HPCL. SMCs differentiation was evaluated using specific genes and proteins. Immobilization of heparin was confirmed by amide I (3427 cm−1) and it was significantly raised on HPCL scaffolds. SMCs + HPCL group revealed the highest cell viability and the most significant increase in differentiation-related genes and proteins at 7 days (p < 0.05). HPCL nanofibers have an effect on SMCs differentiation, which are the functional units of the ureter. Therefore, they could represent a valuable tool for tissue engineering applications in ureter repair. [Display omitted] • Electrospinning technology provides a wide range of interesting and different alternatives for ureteral engineering. • The SMCs seeded onto HPCL scaffolds in particular could be employed as seed cells to generate a tissue-engineered ureter. • HPCL coatings could interact with the body to remodel artificial blood vessels similar to native veins. • The artificial medical devices could induce tissue regeneration on device surfaces while controlling the immune response. [ABSTRACT FROM AUTHOR]

In multicellular organisms, stem cells are impacted by microenvironmental resources such as nutrient availability and oxygen tension for their survival, growth, and differentiation. However, the accessibility of these resources in the pericellular environment greatly varies from organ to organ. This divergence in resource availability leads to variations in the potency and differentiation potential of stem cells. This study aimed to explore the distinct effects of glucose and fructose, as well as different oxygen tensions, on the growth dynamics, cytokine production, and differentiation of stem cells. We showed that replacing glucose with fructose subjected stem cells to stress, resulting in increased Hif1α expression and stability, which in turn led to a reduction in cell proliferation, and alterations in cytokine production. However, fructose failed to induce differentiation of human mesenchymal stem cells (hMSCs) as well as mouse fibroblasts into mature adipocytes compared to glucose, despite the upregulation of key markers of adipogenesis, including C/EBPβ, and PPARγ. Conversely, we showed that fructose induced undifferentiated mouse fibroblasts to release cytokines associated with senescence, including IL1α1, IL6, IL8, MCP1, and TNF1α, suggesting that these cells were undergoing lipolysis. Taken together, our results suggest that altering the culture conditions through changes in hexose levels and oxygen tension places considerable stress on stem cells. Additional research is required to further characterize the mechanisms governing stem cell response to their microenvironments. [ABSTRACT FROM AUTHOR]

Simple Summary: Canine bone marrow-derived mesenchymal stem cells represent a potential starting source for the in vitro generation of functional insulin-producing cells that can be used in the clinical setting for treating diabetes mellitus type 1 in humans and dogs. Given the similar pathology and the close coexistence between humans and dogs, canine natural diabetes represents an excellent study model for translational research in human regenerative medicine. This work aims to generate glucose-responsive insulin-producing cells in vitro from canine bone marrow-derived mesenchymal stem cells using a two- and three-step protocol. Based on a single experiment, the three-step protocol proved effective in generating insulin-producing and secreting cells, but they were not responsive to glucose stimulation. Further experiments are needed to confirm this preliminary interesting result. In a clinical application perspective, a protocol capable of generating glucose-responsive insulin-producing cells is an indispensable feature. Cell-based therapy using insulin-producing cells (IPCs) is anticipated as an alternative treatment option to insulin injection or pancreatic islet transplantation for the treatment of diabetes mellitus in both human and veterinary medicine. Several protocols were reported for the differentiation of mesenchymal stem cells (MSCs) into IPCs; to date, glucose-responsive IPCs have only been obtained from canine adipose tissue-derived MSCs (cAD-MSCs), but not from canine bone marrow-derived MSCs (cBM-MSCs). Therefore, this study aims to generate in vitro glucose-responsive IPCs from cBM-MSCs using two differentiation protocols: a two-step protocol using trichostatin (TSA) and a three-step protocol using mercaptoethanol to induce pancreatic and duodenal homeobox gene 1 (PDX-1) expression. A single experiment was carried out for each protocol. BM-MSCs from one dog were successfully cultured and expanded. Cells exposed to the two-step protocol appeared rarely grouped to form small clusters; gene expression analysis showed a slight increase in PDX-1 and insulin expression, but no insulin protein production nor secretion in the culture medium was detected either under basal conditions or following glucose stimulation. Conversely, cells exposed to the three-step protocol under a 3D culture system formed colony-like structures; insulin gene expression was upregulated compared to undifferentiated control and IPCs colonies secreted insulin in the culture medium, although insulin secretion was not enhanced by high-glucose culture conditions. The single experiment results suggest that the three-step differentiation protocol could generate IPCs from cBM-MSCs; however, further experiments are needed to confirm these data. The ability of IPCs from cBM- MSCs to produce insulin, described here for the first time, is a preliminary interesting result. Nevertheless, the IPCs' unresponsiveness to glucose, if confirmed, would affect its clinical application. Further studies are necessary to establish a differentiation protocol in this perspective. [ABSTRACT FROM AUTHOR]

Mesenchymal stem cells (MSCs) exhibit multipotency, self-renewal, and immune-modulatory properties, making them promising in regenerative medicine, particularly in cardiovascular treatments. However, optimizing the MSC source and induction method of cardiac differentiation is challenging. This study compares the cardiomyogenic potential of bone marrow (BM)-MSCs and adipose-derived (AD)-MSCs using 5-Azacytidine (5-Aza) alone or combined with low doses of Fibroblast Growth Factor (FGF) and Insulin-like Growth Factor (IGF). BM-MSCs and AD-MSCs were differentiated using two protocols: 10 μmol 5-Aza alone and 10 μmol 5-Aza with 1 ng/mL FGF and 10 ng/mL IGF. Morphological, transcriptional, and translational analyses, along with cell viability assessments, were performed. Both the MSC types exhibited similar morphological changes; however, AD-MSCs achieved 70–80% confluence faster than BM-MSCs. Surface marker profiling confirmed CD29 and CD90 positivity and CD45 negativity. The differentiation protocols led to cell flattening and myotube formation, with earlier differentiation in AD-MSCs. The combined protocol reduced cell mortality in BM-MSCs and enhanced the expression of cardiac markers (MEF2c, Troponin I, GSK-3β), particularly in BM-MSCs. Immunofluorescence confirmed cardiac-specific protein expression in all the treated groups. Both MSC types exhibited the expression of cardiac-specific markers indicative of cardiomyogenic differentiation, with the combined treatment showing superior efficiency for BM-MSCs. [ABSTRACT FROM AUTHOR]

Introduction: Spheroids are spherical aggregates of cells that mimic the three-dimensional (3D) architecture of tissues more closely than traditional two dimensional (2D) cultures. Spheroids of adipose stem cells (SASCs) show special features such as high multilineage differentiation potential and immunomodulatory activity. These properties have been attributed to their secreted factors, such as cytokines and growth factors. Moreover, a key role is played by the extracellular vesicles (EVs), which lead a heterogeneous cargo of proteins, mRNAs, and small RNAs that interfere with the pathways of the recipient cells. Purpose: The aim of this work was to characterize the composition of the secretome and exosome from SASCs and evaluate their regenerative potential. Materials and Methods: SASCs were extracted from adipose samples of healthy individuals after signing informed consent. The exosomes were isolated and characterized by Dinamic Light Scattering (DLS), Scanning Electron Microscopy (SEM), and Western blotting analyses. The expression of mRNAs and miRNAs were evaluated through real-time PCR. Lastly, a wound-healing assay was performed to investigate their regenerative potential on different cell cultures. Results: The SASCs' exosomes showed an up-regulation of NANOG and SOX2 mRNAs, typical of stemness maintenance, as well as miR126 and miR146a, related to angiogenic and osteogenic processes. Moreover, the exosomes showed a regenerative effect. Conclusions: The SASCs' secretome carried paracrine signals involved in stemness maintenance, pro-angiogenic and pro-osteogenic differentiation, immune system regulation, and regeneration. [ABSTRACT FROM AUTHOR]

• SERPINA3 was rapidly induced during chondrogenic differentiation from mesenchymal stem cells. • Depletion of SERPINA3 using siRNA led to reduced pellet size and glycosaminoglycan content of cartilage. • RNA sequencing reveals loss of chondrogenic gene expression following SERPINA3 knockdown. • We observed that depletion of this serpin abrogated the induction of the SOX9 protein at early time points. Serine proteinase inhibitors (serpins) are a family of structurally similar proteins which regulate many diverse biological processes from blood coagulation to extracellular matrix (ECM) remodelling. Chondrogenesis involves the condensation and differentiation of mesenchymal stem cells (MSCs) into chondrocytes which occurs during early development. Here, and for the first time, we demonstrate that one serpin, SERPINA3 (gene name SERPINA3, protein also known as alpha-1 antichymotrypsin), plays a critical role in chondrogenic differentiation. We observed that SERPINA3 expression was markedly induced at early time points during in vitro chondrogenesis. We examined the expression of SERPINA3 in human cartilage development, identifying significant enrichment of SERPINA3 in developing cartilage compared to total limb, which correlated with well-described markers of cartilage differentiation. When SERPINA3 was silenced using siRNA, cartilage pellets were smaller and contained lower proteoglycan as determined by dimethyl methylene blue assay (DMMB) and safranin-O staining. Consistent with this, RNA sequencing revealed significant downregulation of genes associated with cartilage ECM formation perturbing chondrogenesis. Conversely, SERPINA3 silencing had a negligible effect on the gene expression profile during osteogenesis suggesting the role of SERPINA3 is specific to chondrocyte differentiation. The global effect on cartilage formation led us to investigate the effect of SERPINA3 silencing on the master transcriptional regulator of chondrogenesis, SOX9. Indeed, we observed that SOX9 protein levels were markedly reduced at early time points suggesting a role for SERPINA3 in regulating SOX9 expression and activity. In summary, our data support a non-redundant role for SERPINA3 in enabling chondrogenesis via regulation of SOX9 levels. [ABSTRACT FROM AUTHOR]

Collagen hydrogel has been shown promise as an inducer for chondrogenic differentiation of bone marrow mesenchymal stem cells (BMSCs), contributing to the repair of cartilage defects. However, the precise molecular mechanism underlying this phenomenon remains poorly elucidated. Here, we induced chondrogenic differentiation of BMSCs using collagen hydrogel and identified 4451 differentially expressed genes (DEGs) through transcriptomic sequencing. Our analysis revealed that DEGs were enriched in the focal adhesion pathway, with a notable decrease in expression levels in the collagen hydrogel group compared to the control group. Protein-protein interaction network analysis suggested that actinin alpha 1 (ACTN1) and actinin alpha 4 (ACTN4), two proteins also involved in cytoskeletal recombination, may be crucial in collagen hydrogel-induced chondrogenic differentiation of BMSCs. Additionally, we found that N6-methyladenosine RNA methylation (m6A) modification was involved in collagen hydrogel-mediated chondrogenic differentiation, with fat mass and obesity-associated protein (FTO) implicated in regulating the expression of ACTN1 and ACTN4. These findings suggest that collagen hydrogel might regulate focal adhesion and actin cytoskeletal signaling pathways through down-regulation of ACTN1 and ACTN4 mRNA via FTO-mediated m6A modification, ultimately driving chondrogenic differentiation of BMSCs. In conclusion, our study provides valuable insights into the molecular mechanisms of collagen hydrogel-induced chondrogenic differentiation of BMSCs, which may aid in developing more effective strategies for cartilage regeneration. [ABSTRACT FROM AUTHOR]

Heterotopic ossification of the elbow (HOE) is a complicated pathologic process characterized by extra bone formation in the elbow. Bone formation is a complex developmental process involving the differentiation of mesenchymal stem cells into osteoblasts. The aim of this study was to explore the cellular origin and progression of HOE by single-cell RNA sequencing. We identified 13 clusters of cells in HOE and further analyzed the subclusters for 4 of the main cell types. Six subclusters of osteoblasts, nine subclusters of chondrocytes, six subclusters of fibroblasts, and five subclusters of mononuclear phagocytes (MPs) were identified and analyzed. The new findings on osterix (OSX) and SOX9 expression in osteoblast subclusters and chondrocyte subclusters indicate that HOE is mediated through endochondral ossification. Further identification of the corresponding signature gene sets of distinct subclusters indicated that subclusters of osteoblasts_3, osteoblasts_4, osteoblasts_5, and osteoblasts_6 are relatively more mature during the osteoblastic progression of HOE. The trajectory analysis of the osteoblasts demonstrated that some genes were gradually downregulated, such as CRYAB, CCL3, SFRP4, WIF1, and IGFBP3, while other critical genes were upregulated, such as VCAN, IGFBP4, FSTL1, POSTN, MDK, THBS2, and ALPL, suggesting that these factors may participate in HOE progression. Cell-cell communication networks revealed extensive molecular interactions among the 13 HOE clusters. Ligand-receptor pairs for IL6, COL24A1, COL22A1, VWF, FZD6, FGF2, and NOTCH1 were identified, suggesting that multiple signaling pathways may be involved in HOE. In conclusion, this study provided the cellular atlas for HOE. We have established a greater extent of the heterogeneity of HOE cells than previously known through transcriptomic analysis at the single-cell level. We have observed gradual patterns of signature gene expression during the differentiation and maturation progression of osteoblasts from stem cells in HOE with higher resolution. The cell heterogeneity of HOE deserves further investigation to pave the way for identification of potential targets for HOE early diagnosis and therapeutic treatment. [ABSTRACT FROM AUTHOR]

Mesenchymal stem cells (MSCs) have promising potential for bone tissue engineering in bone healing and regeneration. They are regarded as such due to their capacity for self-renewal, multiple differentiation, and their ability to modulate the immune response. However, changes in the molecular pathways and transcription factors of MSCs in osteogenesis can lead to bone defects and metabolic bone diseases. DNA methylation is an epigenetic process that plays an important role in the osteogenic differentiation of MSCs by regulating gene expression. An increasing number of studies have demonstrated the significance of DNA methyltransferases (DNMTs), Ten-eleven translocation family proteins (TETs), and MSCs signaling pathways about osteogenic differentiation in MSCs. This review focuses on the progress of research in these areas. [ABSTRACT FROM AUTHOR]

The fracture healing outcome is largely dependent on the quantities as well as osteogenic differentiation capacities of mesenchymal stem cells (MSCs) at the lesion site. Herein, macrophage membrane (MM)-reversibly cloaked nanocomplexes (NCs) are engineered for the lesion-targeted and hierarchical co-delivery of short stromal derived factor-1α peptide (sSDF-1α) and Ckip-1 small interfering RNA (Ckip-1 siRNA, siCkip-1) to promote bone repair by concurrently fostering recruitment and osteogenic differentiation of endogenous MSCs. To construct the NCs, a membrane-penetrating α-helical polypeptide first assembles with siCkip-1, and the cationic NCs are sequentially coated with catalase and an outer shell of sSDF-1α-anchored MM. Due to MM-assisted inflammation homing, intravenously injected NCs could efficiently accumulate at the fractured femur, where catalase decomposes the local hydrogen peroxide to generate oxygen bubbles that drives the shedding of sSDF-1α-anchored MM in the extracellular compartment. The exposed, cationic inner core thus enables robust trans-membrane delivery into MSCs to induce Ckip-1 silencing. Consequently, sSDF-1α-guided MSCs recruitment cooperates with siCkip-1-mediated osteogenic differentiation to facilitate bone formation and accelerate bone fracture healing. This study provides an enlightened strategy for the hierarchical co-delivery of macromolecular drugs into different cellular compartments, and it also renders a promising modality for the management of fracture healing. [ABSTRACT FROM AUTHOR]

BACKGROUND: Growth differentiation factor 5, a member of the transforming growth factor-β superfamily and bone morphogenetic protein family, plays an important role in articular cartilage injury repair, bone regeneration, improvement of intervertebral disc degeneration, tendon healing, and neurodevelopment. OBJECTIVE: To review the research progress of growth differentiation factor 5 in inducing chondrocytes, nucleus pulposus-like cells, tendon cell differentiation, as well as inducing bone formation and neurodevelopment. METHODS: The search terms “growth differentiation factor 5, articular cartilage, bone, nucleus pulposus cells, tendon, nerve regeneration” were used in CNKI, WanFang and PubMed. According to the inclusion and exclusion criteria, the articles not related to the subject matter were excluded and 69 articles related to growth differentiation factor 5 were included. RESULTS AND CONCLUSION: (1) Growth differentiation factor 5 can induce chondrogenic and osteoblastic differentiation of mesenchymal stem cells, but the concentration boundary of growth differentiation factor 5 to induce chondrogenic or osteoblastic differentiation remains unclear. (2) Growth differentiation factor 5 can induce mesenchymal stem cells to differentiate into nucleus pulposus cells, which may play a role in the treatment of intervertebral disc degeneration. (3) Growth differentiation factor 5 can induce mesenchymal stem cells to differentiate into tendon cells and play an important role in tendon repair and prevention of postoperative tendon adhesion. (4) Growth differentiation factor 5 can induce neurodevelopment and promote nerve regeneration. [ABSTRACT FROM AUTHOR]

BACKGROUND: It was found that the ligands and receptors of Notch are both cell membrane surface proteins, which are important proteins to mediate intercellular communication, and the Notch signaling pathway plays a crucial regulatory role in the proliferation and differentiation of mesenchymal stem cells. OBJECTIVE: To review the regulatory mechanism of the Notch signaling pathway on the proliferation and differentiation of mesenchymal stem cells, summarize and clarify the research advance in how the Notch signaling pathway regulates the proliferation and differentiation of mesenchymal stem cells, and provide theoretical support for the future use of stem cells to treat various related diseases. METHODS: By using the computer, the first author searched the relevant studies involving Notch signaling pathway regulation of mesenchymal stem cell proliferation and differentiation on CNKI, Wanfang, VIP, PubMed, Web of Science, and Nature databases with Chinese search terms “mesenchymal stem cells, Notch, Notch signaling pathway, proliferation, differentiation” and the English search terms “mesenchymal stem cells, MSC, Notch, Notch signaling pathway, proliferation, differentiation”. Part of the literature was searched in combination with the literature tracing method. Finally, 87 articles were included in the review analysis. RESULTS AND CONCLUSION: (1) Notch signaling pathway is a conserved signaling pathway in multicellular organisms, which plays an important role in regulating cell differentiation, proliferation, apoptosis, and the cell cycle by mediating communication between neighboring cells through receptor-ligand binding. (2) Mesenchymal stem cells are a class of adult stem cells with self-proliferative and multi-directional differentiation potential, which can be regulated by external signaling pathways to affect their proliferation and differentiation. Notch signaling pathway, as one of them, when Notch ligands are activated, the Notch proteins will undergo two protein hydrolysis cleavages to release Notch intracellular structural domain NICD, which then enters the nucleus and thus promotes the transcription of target genes to regulate the proliferation and differentiation of mesenchymal stem cells from different sources, such as bone marrow, adipose, and umbilical cord. However, the specific mechanisms that regulate the proliferation and differentiation of mesenchymal stem cells from different tissue sources of the same species are different. (3) The Notch signaling pathway can regulate the differentiation of mesenchymal stem cells into different target cells, but due to different target cells, the expression levels of receptors or ligands in the Notch signaling pathway vary. (4) Clinical targeting of the Notch signaling pathway to promote mesenchymal stem cells for the treatment of various refractory diseases, such as aplastic anemia, severe joint injuries, ischemic strokes, and myocardial infarctions, has a promising application. (5) By exploring the Notch signaling pathway via regulating the expression levels of its receptors and ligands in bone marrow mesenchymal stem cells from rat, mouse, and human, it can be found that the Notch signaling pathway expression levels in the proliferation and differentiation of mesenchymal stem cells from different species origins are also different. (6) The role of mesenchymal stem cells in tissue engineering has been gradually highlighted due to their advantages of safety, low immune rejection, and wide therapeutic prospects. The Notch signaling pathway regulates the proliferation and differentiation of mesenchymal stem cells with a wide range of influencing factors, and subsequent studies should further optimize the influencing factor variables and explore the standardized studies of regulating the proliferation and differentiation of mesenchymal stem cells. [ABSTRACT FROM AUTHOR]

BACKGROUND: Mesenchymal stem cells are pluripotent stromal cells isolated from a variety of tissues, which can differentiate into osteoblasts under certain conditions. Photobiomodulation, as an external stimulus, can promote osteogenic differentiation combined with other inducers or alone, providing new ideas for solving a series of bone diseases. OBJECTIVE: To review the relevant literature and mechanisms of photobiomodulation-induced osteogenic differentiation of mesenchymal stem cells, which will lay a theoretical foundation for bone tissue engineering using mesenchymal stem cells as seed cells and may offer some suggestions for future studies. METHODS: Relevant articles were searched on CNKI, PubMed and Wed of Science databases with Chinese search terms of “photobiomodulation, low power laser, low level laser, light-emitting diode, mesenchymal stem cells, osteogenic differentiation, biomaterials” and English search terms of “photobiomodulation, low level laser (light), light-emitting diode (LED), mesenchymal stem cell, osteogenic differentiation, biomaterials”. Finally, 88 articles were included for analysis. RESULTS AND CONCLUSION: (1) Photobiomodulation represented by low level laser and diode laser has a positive effect on promoting the proliferation and differentiation of mesenchymal stem cells. (2) Photobiomodulation can induce osteogenic differentiation of mesenchymal stem cells, whose feasibility has been verified in cell and animal experiments. On one hand, photobiomodulation can promote the expansion and differentiation of stem cells in vitro by activating related signaling pathways and up-regulating the expression of osteogenic molecules. On the other hand, photobiomodulation can improve the survival rate of stem cells in vivo, promote homing effect and shorten the healing time of bone defects after stem cells are injected into the body. However, photobiomodulation has a biphasic dose effect, whose laser parameters, experimental environment, cell type and other factors in various studies are different, making the research results lack consistency and difficult to apply in the clinic. (3) Combined with biological materials, other physical factors and drugs, photobiomodulation can also accelerate osteogenic differentiation. (4) In conclusion, photobiomodulation has been used increasingly widely in the medical field with its advantages of non-invasive, efficient and less-side reactions, and its role in bone tissue engineering has gradually become prominent, which provides a new method for the treatment of bone defects and related diseases. Further exploration should be focused on the standardized treatment parameters of photobiomodulation. [ABSTRACT FROM AUTHOR]

Simple Summary: Simple Summary: Mesenchymal stem cells (MSCs) are adult stem cells capable of differentiating into various cell types, including osteoblasts, chondrocytes, and adipocytes. Renowned for their immunomodulatory and regenerative properties, MSCs hold great promise as tools for tissue repair and therapeutic applications. To facilitate the large-scale production of sheep umbilical cord MSCs (UCMSCs), the telomerase reverse transcriptase (TERT) gene was introduced into UCMSCs to promote immortalization. This study provides valuable insights into (a) the proliferation and anti-aging capabilities of transgenic MSCs compared to primary MSCs; (b) the absence of potential tumorigenicity exhibited in TERT-UCMSCs; and (c) the differentiation potential of TERT-UCMSCs. Immortalized MSCs exhibit enhanced proliferation and anti-aging abilities without tumorigenicity concerns, making them a safe immortalized cell line suitable for medical treatments. Mesenchymal stem cells (MSCs) possess significant differentiation potential, making them highly promising in medicine and immunotherapy due to their regenerative capabilities and exosome secretion. However, challenges such as limited cell divisions and complex testing hinder large-scale MSC production. In this study, we successfully established an immortalized MSC line by transfecting the human telomerase reverse transcriptase (TERT) gene into MSCs isolated from pregnant sheep umbilical cords. This approach effectively inhibits cell senescence and promotes cell proliferation, enabling the generation of umbilical cord mesenchymal stem cells (UCMSCs) on a larger scale. Our findings demonstrate that these transfected TERT-UCMSCs exhibit enhanced proliferative capacity and a reduced aging rate compared to regular UCMSCs while maintaining their stemness without tumorigenicity concerns. Consequently, they hold great potential for medical applications requiring large quantities of functional MSCs. [ABSTRACT FROM AUTHOR]

Age-related osteoporosis is characterized by an imbalance between osteogenic and adipogenic differentiation in bone mesenchymal stem cells (BMSCs). Forkhead box O 3 (FoxO3) transcription factor is involved in lifespan and cell differentiation. In this study, we explore whether FoxO3 regulates age-related bone loss and marrow fat accumulation. The expression levels of FoxO3 in BMSCs during aging were detected in vivo and in vitro. To explore the role of FoxO3 in osteogenic and adipogenic differentiation, primary BMSCs were isolated from young and aged mice. FoxO3 expression was modulated by adenoviral vector transfection. The role of FoxO3 in bone–fat balance was evaluated by alizarin red S staining, oil red O staining, quantitative reverse transcription–polymerase chain reaction, Western blot, and histological analysis. Age-related bone loss and fat deposit are associated with downregulation of FoxO3. Overexpression of FoxO3 alleviated age-related bone loss and marrow fat accumulation in aged mice. Mechanistically, FoxO3 reduced adipogenesis and enhanced osteogenesis of BMSCs via downregulation of PPAR-γ and Notch signaling, respectively. In conclusion, FoxO3 is an essential factor controlling the fate of BMSCs and is a potential target for the prevention of age-related osteoporosis. [ABSTRACT FROM AUTHOR]

Certain miRNAs, notably miR29c, demonstrate a remarkable capacity to regulate cellular osteogenic differentiation. However, their application in tissue regeneration is hampered by their inherent instability and susceptibility to degradation. In this study, we developed a novel miR29c delivery system utilising tetrahedral framework nucleic acids (tFNAs), aiming to enhance its stability and endocytosis capability, augment the efficacy of miR29c, foster osteogenesis in bone marrow mesenchymal stem cells (BMSCs), and significantly improve the repair of critical‐sized bone defects (CSBDs). We confirmed the successful synthesis and biocompatibility of sticky ends‐modified tFNAs (stFNAs) and miR29c‐modified stFNAs (stFNAs‐miR29c) through polyacrylamide gel electrophoresis, microscopy scanning, a cell counting kit‐8 assay and so on. The mechanism and osteogenesis effects of stFNAs‐miR29c were explored using immunofluorescence staining, western blotting, and reserve transcription quantitative real‐time polymerase chain reaction. Additionally, the impact of stFNAs‐miR29c on CSBD repair was assessed via micro‐CT and histological staining. The nano‐carrier, stFNAs‐miR29c was successfully synthesised and exhibited exemplary biocompatibility. This nano‐nucleic acid material significantly upregulated osteogenic differentiation‐related markers in BMSCs. After 2 months, stFNAs‐miR29c demonstrated significant bone regeneration and reconstruction in CSBDs. Mechanistically, stFNAs‐miR29c enhanced osteogenesis of BMSCs by upregulating the Wnt signalling pathway, contributing to improved bone tissue regeneration. The development of this novel nucleic acid nano‐carrier, stFNAs‐miR29c, presents a potential new avenue for guided bone regeneration and bone tissue engineering research. [ABSTRACT FROM AUTHOR]

This study assessed the biocompatibility of two types of nanogold composites: fibronectin-gold (FN-Au) and collagen-gold (Col-Au). It consisted of three main parts: surface characterization, in vitro biocompatibility assessments, and animal models. To determine the structural and functional differences between the materials used in this study, atomic force microscopy, Fourier-transform infrared spectroscopy, and ultraviolet-visible spectrophotometry were used to investigate their surface topography and functional groups. The F-actin staining, proliferation, migration, reactive oxygen species generation, platelet activation, and monocyte activation of mesenchymal stem cells (MSCs) cultured on the FN-Au and Col-Au nanocomposites were investigated to determine their biological and cellular behaviors. Additionally, animal biocompatibility experiments measured capsule formation and collagen deposition in female Sprague–Dawley rats. The results showed that MSCs responded better on the FN-Au and Col-AU nanocomposites than on the control (tissue culture polystyrene) or pure substances, attributed to their incorporation of an optimal Au concentration (12.2 ppm), which induced significant surface morphological changes, nano topography cues, and better biocompatibility. Moreover, neuronal, endothelial, bone, and adipose tissues demonstrated better differentiation ability on the FN-Au and Col-Au nanocomposites. Nanocomposites have a crucial role in tissue engineering and even vascular grafts. Finally, MSCs were demonstrated to effectively enhance the stability of the endothelial structure, indicating that they can be applied as promising alternatives to clinics in the future. [ABSTRACT FROM AUTHOR]

Reconstruction of injured bone remains challenging in the clinic owing to the lack of suitable bone grafts. The utilization of PAI‐1 transfected‐conditioned media (P‐CM) has demonstrated its ability to facilitate the differentiation process of mesenchymal stem cells (MSCs), potentially serving as a crucial mediator in tissue regeneration. This research endeavored to explore the therapeutic potential of P‐CM concerning the differentiation of human bone marrow mesenchymal stem cells (hBMSCs). To assess new bone formation, a rat calvaria critical defect model was employed, while in vitro experiments involved the use of the alizarin Red‐S mineral induction test. In the rat calvaria critical defect model, P‐CM treatment resulted in significan new bone formation. In vitro, P‐CM treated hBMSCs displayed robust osteogenesis compared to the control group, as demonstrated by the mineral induction test using alizarin Red‐S. P‐CM with hydroxyapatite/β‐tricalcium phosphate/fibrin gel treatment significantly exhibited new bone formation, and the expression of osteogenic associated markers was enhanced in the P‐CM‐treated group. In conclusion, results demonstrate that P‐CM treatment significantly enhanced the osteogenic differantiation efficiency and new bone formation, thus could be used as an ideal therapeutic biomolecule for constructing bone‐specific implants, especially for orthopedic and dental applications. [ABSTRACT FROM AUTHOR]

Tuning cell adhesion geometry can affect cytoskeleton organization and the distribution of cytoskeleton forces, which play critical roles in controlling cell functions. To elucidate the geometrical relationship with cytoskeleton force distribution, it is necessary to control cell morphology. In this study, a series of dextral vortex micropatterns were prepared to precisely control cell morphology for investigating the influence of the curvature degree of adhesion curves on intracellular force distribution and stem cell differentiation at a sub-cellular level. Peripherial actin filaments of micropatterned cells were assembled along the adhesion curves and showed different orientations, filament thicknesses and densities. Focal adhesion and cytoskeleton force distribution were dependent on the curvature degree. Intracellular force distribution was also regulated by adhesion curves. The cytoskeleton and force distribution affected the osteogenic differentiation of mesenchymal stem cells through a YAP/TAZ-mediated mechanotransduction process. Thus, regulation of cell adhesion curvature, especially at cytoskeletal filament level, is critical for cell function manipulation. In this study, a series of dextral micro-vortexes were prepared and used for the culture of human mesenchymal stem cells (hMSCs) to precisely control adhesive curvatures (0°, 30°, 60°, and 90°). The single MSCs on the micropatterns had the same size and shape but showed distinct focal adhesion (FA) and cytoskeleton orientations. Cellular nanomechanics were observed to be correlated with the curvature degrees, subsequently influencing nuclear morphological features. As a consequence, the localization of the mechanotransduction sensor and activator-YAP/TAZ was affected, influencing osteogenic differentiation. The results revealed the pivotal role of adhesive curvatures in the manipulation of stem cell differentiation via the machanotransduction process, which has rarely been investigated. [Display omitted] [ABSTRACT FROM AUTHOR]

Posttranslational modifications (PTMs) are crucial regulatory mechanisms for cellular differentiation and organismal development. Acylation modification is one of the main PTMs that plays a pivotal role in regulating the osteogenic differentiation of mesenchymal stem cells and is a focal point of research in bone tissue regeneration. However, its mechanism remains incompletely understood. This article aims to investigate the impact of protein crotonylation on osteogenic differentiation in periodontal ligament stem cells (PDLSCs) and elucidate its underlying mechanisms. Western blot analysis identified that the modification level of acetylation, crotonylation, and succinylation were significantly upregulated after osteogenic induction of PDLSCs. Subsequently, sodium crotonate (NaCr) was added to the medium and acyl-CoA synthetase short-chain family member 2 (ACSS2) was knocked down by short hairpin RNA plasmids to regulate the total level of protein crotonylation. The results indicated that treatment with NaCr promoted the expression of osteogenic differentiation-related factors in PDLSCs, whereas silencing ACSS2 had the opposite effect. In addition, mass spectrometry analysis was used to investigate the comprehensive analysis of proteome-wide crotonylation in PDLSCs under osteogenic differentiation. The analysis revealed that the level of protein crotonylation related to the PI3K-AKT signaling pathway was significantly upregulated in PDLSCs after osteogenic induction. Treatment with NaCr and silencing ACSS2 affected the activation of the PI3K-AKT signaling pathway. Collectively, our study demonstrates that protein crotonylation promotes osteogenic differentiation of PDLSCs via the PI3K-AKT pathway, providing a novel targeting therapeutic approach for bone tissue regeneration. [ABSTRACT FROM AUTHOR]

Stem cell therapy has the potential to meet unsolved problems in tissue repair and regeneration, particularly in the neural tissues. However, an optimal source has not yet been found. Growing evidence indicates that positive effects produced in vivo by mesenchymal stem cells (MSCs) can be due not only to their plasticity but also to secreted molecules including extracellular vesicles (EVs) and the extracellular matrix (ECM). Trophic effects produced by MSCs may reveal the key to developing effective tissue-repair strategies, including approaches based on brain implants or other implantable neural electrodes. In this sense, MSCs will become increasingly valuable and needed in the future. The placenta is a temporary organ devoted to protecting and supporting the fetus. At the same time, the placenta represents an abundant and extremely convenient source of MSCs. Nonetheless, placenta-derived MSCs (P-MSCs) remain understudied as compared to MSCs isolated from other sources. This review outlines the limited literature describing the neuroregenerative effects of P-MSC-derived biomaterials and advocates for exploiting the potential of this untapped source for human regenerative therapies. [ABSTRACT FROM AUTHOR]

BACKGROUND: Intervertebral disk degeneration is a pathological change caused by a series of complex molecular mechanisms that result in the aging and damage of intervertebral discs, ultimately leading to severe clinical symptoms. Traditional Chinese medicine has unique advantages in the treatment of intervertebral disk degeneration due to its low cost, non-addictive nature, multi-target effects, minimally toxic and side effects, and high patient acceptance. OBJECTIVE: To review the latest research results of traditional Chinese medicine monomer intervention-related signaling pathways in the treatment of intervertebral disk degeneration, describe and analyze the action mechanism of traditional Chinese medicine monomer on intervertebral disk degeneration, and provide a new approach and theoretical basis for future basic research and clinical treatment. METHODS: The first author searched for relevant literature from January 2018 to February 2023 in CNKI, PubMed, VIP, and WanFang using the search terms “intervertebral disc, signal pathway”. The articles that did not meet the criteria were excluded after preliminary screening of the titles and abstracts. Finally, 72 articles were selected for review and analysis. RESULTS AND CONCLUSION: Traditional Chinese medicine monomers can regulate multiple classical signaling pathways such as Wnt/β-catenin, PI3K/Akt, mTOR, NF-κB, and MAPK. They achieve this by regulating oxidative stress, adjusting the expression of pro/anti-apoptotic proteins in cells, stimulating cellular autophagy function, reducing stimulation of cell inflammatory factors, increasing the expression of extracellular matrix markers, reducing the production of matrix-degrading enzymes, maintaining the synthesis and stability of extracellular matrix, inducing differentiation of mesenchymal stem cells in the nucleus pulposus into nucleus pulposus cells, promoting endogenous repair and reconstruction, controlling apoptosis and aging of nucleus pulposus cells, and increasing the activity of nucleus pulposus cells. These actions improve the microenvironment within the intervertebral disc, maintain the normal physiological function of the intervertebral disc, and delay intervertebral disc degeneration. [ABSTRACT FROM AUTHOR]

Harnessing endogenous stem/progenitor cells to enhance extracellular matrix (ECM) deposition in the nucleus pulposus (NP) is considered as a potential treatment for intervertebral disc degeneration (IVDD), but is limited by the lack of suitable scaffolds for cell infiltration and growth, as well as the tailored release of bioactive factors. Herein, an injectable cell‐free microgel assembly (MA‐TNS) with interconnected microporous structure is developed to recruit stem/progenitor cells and induce the differentiation of the recruited cells by releasing stromal cell‐derived factor‐1α (SDF‐1α) and transforming growth factor‐β1 (TGF‐β1) sequentially. TGF‐β1 is initially loaded by the chondroitin sulfate/gelatin nanoparticles. Together with SDF‐1α, these nanoparticles are co‐encapsulated into the photo‐cross‐linked microgels, which are then assembled into a microporous scaffold via dynamic boronate ester bonds. An initial rapid release of SDF‐1α followed by a sustained release of TGF‐β1 lasting over 28 days is achieved. MA‐TNS significantly promotes the recruitment, infiltration, and chondrocyte‐like differentiation of marrow mesenchymal stem cells in vitro. Furthermore, in vivo experiments on rats and cynomolgus monkeys prove that MA‐TNS can inhibit IVDD and recover ECM deposition markedly, thereby enabling long‐term NP reconstruction. The resulting efficacy in rats and nonhuman primates supports that MA‐TNS is a promising scaffold for intervertebral disc repair and regeneration. [ABSTRACT FROM AUTHOR]