The impact of endocrine-disrupting chemicals on stem cells: Mechanisms and implications for human health.

Endocrine-disrupting chemicals (EDCs) are compounds, either natural or man-made, that interfere with the normal functioning of the endocrine system. There is increasing evidence that exposure to EDCs can have profound adverse effects on reproduction, metabolic disorders, neurological alterations, and increased risk of hormone-dependent cancer. Stem cells (SCs) are integral to these pathological processes, and it is therefore crucial to understand how EDCs may influence SC functionality. This review examines the literature on different types of EDCs and their effects on various types of SCs, including embryonic, adult, and cancer SCs. Possible molecular mechanisms through which EDCs may influence the phenotype of SCs are also evaluated. Finally, the possible implications of these effects on human health are discussed. The available literature demonstrates that EDCs can influence the biology of SCs in a variety of ways, including by altering hormonal pathways, DNA damage, epigenetic changes, reactive oxygen species production and alterations in the gene expression patterns. These disruptions may lead to a variety of cell fates and diseases later in adulthood including increased risk of endocrine disorders, obesity, infertility, reproductive abnormalities, and cancer. Therefore, the review emphasizes the importance of raising broader awareness regarding the intricate impact of EDCs on human health.

Regenerative Potential of Dental Pulp Stem Cells in Response to a Bioceramic Dental Sealer and Photobiomodulation: An In Vitro Study.

AIMS: This study aims to assess the synergistic effect of utilizing a bioceramic sealer, NeoPutty, with photobiomodulation (PBM) on dental pulp stem cells (DPSCs) for odontogenesis. MATERIALS AND METHODS: Dental pulp stem cells were collected from 10 premolars extracted from healthy individuals. Dental pulp stem cells were characterized using an inverted-phase microscope to detect cell shape and flow cytometry to detect stem cell-specific surface antigens. Three experimental groups were examined: the NP group, the PBM group, and the combined NP and PBM group. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) experiment was conducted to assess the viability of DPSCs. The odontogenic differentiation potential was analyzed using Alizarin red staining, RT-qPCR analysis of odontogenic genes DMP-1, DSPP, and alkaline phosphatase (ALP), and western blot analysis for detecting BMP-2 and RUNX-2 protein expression. An analysis of variance (ANOVA) followed by a post hoc t-test was employed to examine and compare the mean values of the results. RESULTS: The study showed a notable rise in cell viability when NP and PBM were used together. Odontogenic gene expression and the protein expression of BMP-2 and RUNX-2 were notably increased in the combined group. The combined effect of NeoPutty and PBM was significant in enhancing the odontogenic differentiation capability of DPSCs. CONCLUSION: The synergistic effect of NeoPutty and PBM produced the most positive effect on the cytocompatibility and odontogenic differentiation potential of DPSCs. CLINICAL SIGNIFICANCE: Creating innovative regenerative treatments to efficiently and durably repair injured dental tissues. How to cite this article: Alshawkani HA, Mansy M, Al Ankily M, et al. Regenerative Potential of Dental Pulp Stem Cells in Response to a Bioceramic Dental Sealer and Photobiomodulation: An In Vitro Study. J Contemp Dent Pract 2024;25(4):313-319.

Variations in cell plasticity and proliferation underlie distinct modes of regeneration along the antero-posterior axis in the annelid Platynereis.

The capacity to regenerate lost tissues varies significantly among animals. Some phyla, such as the annelids, display substantial regenerating abilities, although little is known about the cellular mechanisms underlying the process. To precisely determine the origin, plasticity and fate of the cells participating in blastema formation and posterior end regeneration after amputation in the annelid Platynereis dumerilii, we developed specific tools to track different cell populations. Using these tools, we find that regeneration is partly promoted by a population of proliferative gut cells whose regenerative potential varies as a function of their position along the antero-posterior axis of the worm. Gut progenitors from anterior differentiated tissues are lineage restricted, whereas gut progenitors from the less differentiated and more proliferative posterior tissues are much more plastic. However, they are unable to regenerate the stem cells responsible for the growth of the worms. Those stem cells are of local origin, deriving from the cells present in the segment abutting the amputation plane, as are most of the blastema cells. Our results favour a hybrid and flexible cellular model for posterior regeneration in Platynereis relying on different degrees of cell plasticity.

Intestinal organoids to model Salmonella infection and its impact on progenitors.

In order to survive and replicate, Salmonella has evolved mechanisms to gain access to intestinal epithelial cells of the crypt. However, the impact of Salmonella Typhimurium on stem cells and progenitors, which are responsible for the ability of the intestinal epithelium to renew and protect itself, remains unclear. Given that intestinal organoids growth is sustained by stem cells and progenitors activity, we have used this model to document the effects of Salmonella Typhimurium infection on epithelial proliferation and differentiation, and compared it to an in vivo model of Salmonella infection in mice. Among gut segments, the caecum was preferentially targeted by Salmonella. Analysis of infected crypts and organoids demonstrated increased length and size, respectively. mRNA transcription profiles of infected crypts and organoids pointed to upregulated EGFR-dependent signals, associated with a decrease in secretory cell lineage differentiation. To conclude, we show that organoids are suited to mimic the impact of Salmonella on stem cells and progenitors cells, carrying a great potential to drastically reduce the use of animals for scientific studies on that topic. In both models, the EGFR pathway, crucial to stem cells and progenitors proliferation and differentiation, is dysregulated by Salmonella, suggesting that repeated infections might have consequences on crypt integrity and further oncogenesis.

A new subtype of artificial cell-derived vesicles from dental pulp stem cells with the bioequivalence and higher acquisition efficiency compared to extracellular vesicles.

Extracellular vesicles (EVs) derived from dental pulp stem cells (DPSC) have been shown an excellent efficacy in a variety of disease models. However, current production methods fail to meet the needs of clinical treatment. In this study, we present an innovative approach to substantially enhance the production of 'Artificial Cell-Derived Vesicles (ACDVs)' by extracting and purifying the contents released by the DPSC lysate, namely intracellular vesicles. Comparative analysis was performed between ACDVs and those obtained through ultracentrifugation. The ACDVs extracted from the cell lysate meet the general standard of EVs and have similar protein secretion profile. The new ACDVs also significantly promoted wound healing, increased or decreased collagen regeneration, and reduced the production of inflammatory factors as the EVs. More importantly, the extraction efficiency is improved by 16 times compared with the EVs extracted using ultracentrifuge method. With its impressive attributes, this new subtype of ACDVs emerge as a prospective candidate for the future clinical applications in regenerative medicine.

Oscillation steers differentiation.

The differentiation trajectories defining enteroendocrine (EE) cell heterogeneity remain obscure. In this issue of Cell Stem Cell, Singh et al.1 map the differentiation landscape of EE cells, identifying early oscillating cell progenitor states, which play a critical role in generating terminal EE cell diversity.

Characterisation of germline progenitor cells in the testes of phylostomid bats: Artibeus jamaicensis and Sturnira lilium.

Context A population of sperm progenitor cells, known as Asingle spermatogonia, has been described in mammalian testes. During division cycles in spermatogenesis, some cells will form part of the Asingle spermatogonia group, while others form primary spermatocytes. Thus, during spermatogenesis, spermatogonia are the progenitor cells of spermatozoa. Aims In this study, we characterise the spermatogonial stem cells (SSCs) in the testicles of Artibeus jamaicensis and Sturnira lilium bats. The knowledge generated from this will contribute to the understanding of the biology of germ cells and the mechanisms of spermatogenesis in mammals, generating information on wildlife species that are important for biodiversity. Methods Testes were analysed by light and electron microscopy. Likewise, the expression of specific factors of stem cells (Oct4 and C-kit), germ cells (Vasa), cell proliferation (pH3 and SCP1) and testicular somatic cells (MIS, 3ßHSD and Sox9) was characterised by immunofluorescence and western blot. Key results The histological analysis enabled the location of type Asingle, Apaired and Aaligned spermatogonia in the periphery of the seminiferous tubules adjacent to Sertoli cells. The expression of genes of stem and germ cells made it possible to corroborate the distribution of the SSCs. Conclusions Results indicate that type Asingle spermatogonia were not randomly distributed, since proliferative activity was detected in groups of cells adjacent to the seminiferous tubules membrane, suggesting the localisation of spermatogonial niches in a specific region of testes. Implications This study provides evidence for the existence of SSCs in the testis of chiropterans that contribute to the renewal of germline progenitor cells to maintain the reproduction of the organisms.

Novel L-(CaP-ZnP)/SA Nanocomposite Hydrogel with Dual Anti-Inflammatory and Mineralization Effects for Efficient Vital Pulp Therapy.

Background: Vital pulp therapy (VPT) is considered a conservative treatment for preserving pulp viability in caries and trauma-induced pulpitis. However, Mineral trioxide aggregate (MTA) as the most frequently used repair material, exhibits limited efficacy under inflammatory conditions. This study introduces an innovative nanocomposite hydrogel, tailored to simultaneously target anti-inflammation and dentin mineralization, aiming to efficiently preserve vital pulp tissue. Methods: The L-(CaP-ZnP)/SA nanocomposite hydrogel was designed by combining L-Arginine modified calcium phosphate/zinc phosphate nanoparticles (L-(CaP-ZnP) NPs) with sodium alginate (SA), and was characterized with TEM, SEM, FTIR, EDX, ICP-AES, and Zeta potential. In vitro, we evaluated the cytotoxicity and anti-inflammatory properties. Human dental pulp stem cells (hDPSCs) were cultured with lipopolysaccharide (LPS) to induce an inflammatory response, and the cell odontogenic differentiation was measured and possible signaling pathways were explored by alkaline phosphatase (ALP)/alizarin red S (ARS) staining, qRT-PCR, immunofluorescence staining, and Western blotting, respectively. In vivo, a pulpitis model was utilized to explore the potential of the L-(CaP-ZnP)/SA nanocomposite hydrogel in controlling pulp inflammation and enhancing dentin mineralization by Hematoxylin and eosin (HE) staining and immunohistochemistry staining. Results: In vitro experiments revealed that the nanocomposite hydrogel was synthesized successfully and presented desirable biocompatibility. Under inflammatory conditions, compared to MTA, the L-(CaP-ZnP)/SA nanocomposite hydrogel demonstrated superior anti-inflammatory and pro-odontogenesis effects. Furthermore, the nanocomposite hydrogel significantly augmented p38 phosphorylation, implicating the involvement of the p38 signaling pathway in pulp repair. Significantly, in a rat pulpitis model, the L-(CaP-ZnP)/SA nanocomposite hydrogel downregulated inflammatory markers while upregulating mineralization-related markers, thereby stimulating the formation of robust reparative dentin. Conclusion: The L-(CaP-ZnP)/SA nanocomposite hydrogel with good biocompatibility efficiently promoted inflammation resolution and enhanced dentin mineralization by activating p38 signal pathway, as a pulp-capping material, offering a promising and advanced solution for treatment of pulpitis.

Transcriptional Control: A Directional Sign at the Crossroads of Adult Hepatic Progenitor Cells' Fates.

Hepatic progenitor cells (HPCs) have a bidirectional potential to differentiate into hepatocytes and bile duct epithelial cells and constitute a second barrier to liver regeneration in the adult liver. They are usually located in the Hering duct in the portal vein region where various cells, extracellular matrix, cytokines, and communication signals together constitute the niche of HPCs in homeostasis to maintain cellular plasticity. In various types of liver injury, different cellular signaling streams crosstalk with each other and point to the inducible transcription factor set, including FoxA1/2/3, YB-1, Foxl1, Sox9, HNF4α, HNF1α, and HNF1ß. These transcription factors exert different functions by binding to specific target genes, and their products often interact with each other, with diverse cascades of regulation in different molecular events that are essential for homeostatic regulation, self-renewal, proliferation, and selective differentiation of HPCs. Furthermore, the tumor predisposition of adult HPCs is found to be significantly increased under transcriptional factor dysregulation in transcriptional analysis, and the altered initial commitment of the differentiation pathway of HPCs may be one of the sources of intrahepatic tumors. Related transcription factors such as HNF4α and HNF1 are expected to be future targets for tumor treatment.

Hydrogel-Integrated Millifluidic Systems: Advancing the Fabrication of Mucus-Producing Human Intestinal Models.

The luminal surface of the intestinal epithelium is protected by a vital mucus layer, which is essential for lubrication, hydration, and fostering symbiotic bacterial relationships. Replicating and studying this complex mucus structure in vitro presents considerable challenges. To address this, we developed a hydrogel-integrated millifluidic tissue chamber capable of applying precise apical shear stress to intestinal models cultured on flat or 3D structured hydrogel scaffolds with adjustable stiffness. The chamber is designed to accommodate nine hydrogel scaffolds, 3D-printed as flat disks with a storage modulus matching the physiological range of intestinal tissue stiffness (~3.7 kPa) from bioactive decellularized and methacrylated small intestinal submucosa (dSIS-MA). Computational fluid dynamics simulations were conducted to confirm a laminar flow profile for both flat and 3D villi-comprising scaffolds in the physiologically relevant regime. The system was initially validated with HT29-MTX seeded hydrogel scaffolds, demonstrating accelerated differentiation, increased mucus production, and enhanced 3D organization under shear stress. These characteristic intestinal tissue features are essential for advanced in vitro models as they critically contribute to a functional barrier. Subsequently, the chamber was challenged with human intestinal stem cells (ISCs) from the terminal ileum. Our findings indicate that biomimicking hydrogel scaffolds, in combination with physiological shear stress, promote multi-lineage differentiation, as evidenced by a gene and protein expression analysis of basic markers and the 3D structural organization of ISCs in the absence of chemical differentiation triggers. The quantitative analysis of the alkaline phosphatase (ALP) activity and secreted mucus demonstrates the functional differentiation of the cells into enterocyte and goblet cell lineages. The millifluidic system, which has been developed and optimized for performance and cost efficiency, enables the creation and modulation of advanced intestinal models under biomimicking conditions, including tunable matrix stiffness and varying fluid shear stresses. Moreover, the readily accessible and scalable mucus-producing cellular tissue models permit comprehensive mucus analysis and the investigation of pathogen interactions and penetration, thereby offering the potential to advance our understanding of intestinal mucus in health and disease.

Enhancing Dental Pulp Stem Cell Proliferation and Odontogenic Differentiation with Protein Phosphatase 1-Disrupting Peptide: An In Vitro Study.

The reparative and regenerative capabilities of dental pulp stem cells (DPSCs) are crucial for responding to pulp injuries, with protein phosphatase 1 (PP1) playing a significant role in regulating cellular functions pertinent to tissue healing. Accordingly, this study aimed to explore the effects of a novel cell-penetrating peptide Modified Sperm Stop 1-MSS1, that disrupts PP1, on the proliferation and odontogenic differentiation of DPSCs. Employing MSS1 as a bioportide, DPSCs were cultured and characterized for metabolic activity, cell proliferation, and cell morphology alongside the odontogenic differentiation through gene expression and alkaline phosphatase (ALP) activity analysis. MSS1 exposure induced early DPSC proliferation, upregulated genes related to odontogenic differentiation, and increased ALP activity. Markers associated with early differentiation events were induced at early culture time points and those associated with matrix mineralization were upregulated at mid-culture stages. This investigation is the first to document the potential of a PP1-disrupting bioportide in modulating DPSC functionality, suggesting a promising avenue for enhancing dental tissue regeneration and repair.

The differentiation of Lgr5+ progenitor cells on nanostructures of self-assembled silica beads.

Supporting cells(SCs) have been demonstrated to be a reliable source for regenerating hair cells(HCs). Previous research has reported that Lgr5+ SCs can regenerate HCs both in vitro and in vivo. However, there is limited knowledge about the impact of the material on Lgr5+ cells. In this study, Lgr5+ cells were isolated from neonatal Lgr5-EGFP-CreERT2 transgenic mice by flow cytometry and then plated on self-assembled silica beads (SB). Lgr5+ cell differentiation was observed by immunofluorescence. We found that in the direct differentiation assay, the SB group generated more hair cells than the control group(*p < 0.05). Especially in the SB group, Lgr5+ progenitors generated significantly more Myo7a+ HCs outside of the colony than in the control group(**p < 0.01). In the sphere differentiation assay, we found that the diameter of spheres in the SB group was significantly larger compared to those of the control group(**p < 0.01). However, the difference in the ratio of myo7a+ cell counts was not obvious(P>0.05). The experiment proved that the self-assembled silica beads could promote the differentiation of Lgr5+ progenitors in vitro. Our findings implicate that nanostructures of self-assembled silica beads can be used as vectors for stem cell research in the inner ear.

Influence of the Surface Topography of Titanium Dental Implants on the Behavior of Human Amniotic Stem Cells.

The dental implant surface plays a crucial role in osseointegration. The topography and physicochemical properties will affect the cellular functions. In this research, four distinct titanium surfaces have been studied: machined acting (MACH), acid etched (AE), grit blasting (GBLAST), and a combination of grit blasting and subsequent acid etching (GBLAST + AE). Human amniotic mesenchymal (hAMSCs) and epithelial stem cells (hAECs) isolated from the amniotic membrane have attractive stem-cell properties. They were cultured on titanium surfaces to analyze their impact on biological behavior. The surface roughness, microhardness, wettability, and surface energy were analyzed using interferometric microscopy, Vickers indentation, and drop-sessile techniques. The GBLAST and GBLAST + AE surfaces showed higher roughness, reduced hydrophilicity, and lower surface energy with significant differences. Increased microhardness values for GBLAST and GBLAST + AE implants were attributed to surface compression. Cell viability was higher for hAMSCs, particularly on GBLAST and GBLAST + AE surfaces. Alkaline phosphatase activity enhanced in hAMSCs cultured on GBLAST and GBLAST + AE surfaces, while hAECs showed no mineralization signals. Osteogenic gene expression was upregulated in hAMSCs on GBLAST surfaces. Moreover, α2 and ß1 integrin expression enhanced in hAMSCs, suggesting a surface-integrin interaction. Consequently, hAMSCs would tend toward osteoblastic differentiation on grit-blasted surfaces conducive to osseointegration, a phenomenon not observed in hAECs.

[TNF-α regulated SHED osteogenic differentiation through ERK1/2-Runx2 signaling pathway].

PURPOSE: To investigate the effect of TNF-α on osteogenic differentiation of stem cells from human exfoliated deciduous teeth (SHED), and to analyze the changes of ERK1/2-Runx2 signaling pathway in the regulation process. METHODS: SHED cells were isolated and cultured from normal deciduous permanent teeth of healthy children aged 6-8 years old, and the third passage of SHED cells were taken and divided into control group (osteogenic inducer culture), observation group (osteogenic inducer and TNF-α co-culture) and agonist group (osteogenic inducer, TNF-α and ERK pathway agonist co-culture). The osteogenic differentiation was determined by alizarin red staining. The protein expression levels of Osterix, OPN, ERK1/2, pERK1/2 and Runx2 in SHED cells were determined by Western blot. The expressions of Osterix, OPN, ERK1/2, pERK1/2 and Runx2 mRNA were detected by qRT-PCR. Statistical analysis was performed with SPSS 26.0 software package. RESULTS: Comparison of osteogenic differentiation ability of the three groups of cells showed that red-brown mineralized nodules were observed in the three groups of cells. Compared among the three groups, the control group had the most mineralized nodules, followed by the activation group, and the observation group had the least mineralized nodules. Compared with the control group, the expression levels of Osterix and OPN protein and mRNA in the observation group and the agonist group were significantly decreased, while the expression levels of Osterix and OPN protein and mRNA in the agonist group were significantly higher than those in the observation group. There was no significant difference in the expression levels of ERK1/2 protein and mRNA among the three groups, while the expression levels of pERK1/2 and Runx2 protein and mRNA in the observation group and the agonist group were significantly higher than those in the control group, and the expression levels of pERK1/2 and Runx2 protein and mRNA in the agonist group were significantly higher than those in the observation group. CONCLUSIONS: TNF-α can inhibit osteogenic differentiation of SHED cells, which may be related to the inhibition of ERK1/2-Runx2 signaling pathway.

[Isolation and characterization of normal mandibular periosteal stem cells from human and macaca mulatta and cross-species single-cell analysis].

Objective: To investigate the presence of a distinct stem cell populations different from mesenchymal stem cells in the mandibular periosteum of both human and non-human primates (macaca mulatta), to explore its properties during intramembranous osteogenesis and to establish standard protocols for the isolation, culturing and expanding of mandibular periosteal stem cells (PSC) distinguished from other PSCs in other anatomical regions. Methods: Periosteum was harvested from the bone surface during flap bone removal in patients aged 18-24 years undergoing third molar extraction and from the buccal side of the mandibular premolar region of 6-year-old macaca mulatta respectively, and then subjected to single-cell sequencing using the Illumina platform Novaseq 6000 sequencer. Cross-species single-cell transcriptome sequencing results were compared using homologous gene matching. PSC were isolated from primary tissues using two digestion methods with body temperature and low temperature, and their surface markers (CD200, CD31, CD45 and CD90) were identified by cell flow cytometry. The ability of cell proliferation and three-lineage differentiation of PSC expanded to the third generation in vitro in different species were evaluated. Finally, the similarities and differences in osteogenic properties of PSC and bone marrow mesenchymal stem cells (BMSC) were compared. Results: The single-cell sequencing results indicated that 18 clusters of cell populations were identified after homologous gene matching for dimensionality reduction, and manual cellular annotation was conducted for each cluster based on cell marker databases. The comparison of different digestion protocols proved that the low-temperature overnight digestion protocol can stably isolate PSC from the human and m. mulatta mandibular periosteum and the cells exhibited a fibroblast-like morphology. This research confirmed that PSC of human and m. mulatta had similar proliferation capabilities through the cell counting kit-8 assay. Flow cytometry analysis was then used to identify the cells isolated from the periosteum expressed CD200(+), CD31(-), CD45(-), CD90(-). Then, human and m. mulatta PSC were induced into osteogenesis, adipogenesis, and chondrogenesis to demonstrate their corresponding multi-lineage differentiation capabilities. Finally, comparison with BMSC further clarified the oesteogenesis characteristics of PSC. The above experiments proved that the cells isolated from the periosteum were peiosteal cells with characteristics of stem cells evidenced by their cell morphology, proliferation ability, surface markers, and differentiation ability, and that this group of PSC possessed characteristics different from traditional mesenchymal stem cells. Conclusions: In this study, normal mandibular PSC from humans and m. mulatta were stably isolated and identified for the first time, providing a cellular foundation for investigating the mechanism of mandibular intramembranous osteogenesis, exploring ideal non-human primate models and establishing innovative strategies for clinically mandibular injury repair.

[Preparation and biological characteristics of extracellular matrix vesicle mimetics].

Objective: To investigate the characteristics of extracellular matrix vesicle mimetics prepared by mechanical extrusion and their effects on the cell viability and osteogenic differentiation potential of human periodontal ligament stem cells (PDLSC). Methods: PDLSC derived extracellular matrix vesicles were prepared by collagenase digestion, while the cell derived vesicle mimetics were simulated by mechanical extrusion. The obtained extracellular matrix vesicles and parental cell derived vesicle mimetics were divided into 4 groups: matrix vesicles derived from PDLSC cultured in basic medium for 7 days (PDLSC matrix vesicles, MVs), vesicle mimetics derived from PDLSC cultured in basic medium for 7 days (PDLSC vesicle mimetics, CVMs), matrix vesicles derived from PDLSC cultured in osteogenic inducing medium for 7 days (osteogenic-induced PDLSC matrix vesicles, O-MVs) and vesicle mimetics derived from PDLSC cultured in osteogenic inducing medium for 7 days (osteogenic-induced PDLSC vesicle mimetics, O-CVMs). Vesicles morphologies and sizes were observed by transmission electron microscopy and nanoparticle tracking analysis. Vesicles uptake was detected by immunofluorescence. With PDLSC as the control group, the effects of vesicles on the viability of PDLSC were detected by cell activity assay (cell counting kit-8), and the effects of vesicles on the osteogenic differentiation potential of PDLSC were detected by alizarin red staining and Western blotting. Results: Vesicles in MVs, O-MVs, CVMs and O-CVMs were all observed with a round structure (size 50-250 nm), and could be taken up by PDLSC without affecting the cell viability. Under osteogenic inducing conditions, PDLSC incubated with O-MVs or O-CVMs could produce more mineralized nodules than those in the control group (PDLSC). MVs, O-MVs, CVMs and O-CVMs could promote the expression of osteogenic-related proteins in PDLSC. PDLSC in group O-CVMs showed significant higher expressions of osteogenic-related proteins, including alkaline phosphatase (ALP) (1.571±0.348), osteopontin (OPN) (1.827±0.627) and osteocalcin (OCN) (1.798±0.537) compared to MVs (ALP: 1.156±0.170, OPN: 1.260±0.293, OCN: 1.286±0.302) (P<0.05). Compared to CMVs-incubated PDLSC, O-CVMs-incubated PDLSC expressed more Runt-related transcription factor 2 (1.632±0.455 vs 1.176±0.128) and OPN (1.827±0.627 vs 1.428±0.427) (P<0.05). Moreover, there was no significant difference in the expression levels of osteoblast-related proteins in PDLSC cultured with MVs, O-MVs and CVMs (P>0.05). Conclusions: The vesicle mimetics prepared by mechanical extrusion method are similar in shape and size to the extracellular matrix vesicles. MVs, O-MVs, CVMs and O-CVMs do not affect the cell viability of PDLSC, and can promote the osteogenic differentiation potential of PDLSC to a certain extent.

Calorie restriction activates a gastric Notch-FOXO1 pathway to expand ghrelin cells.

Calorie restriction increases lifespan. Among the tissue-specific protective effects of calorie restriction, the impact on the gastrointestinal tract remains unclear. We report increased numbers of chromogranin A-positive (+), including orexigenic ghrelin+ cells, in the stomach of calorie-restricted mice. This effect was accompanied by increased Notch target Hes1 and Notch ligand Jag1 and was reversed by blocking Notch with DAPT, a gamma-secretase inhibitor. Primary cultures and genetically modified reporter mice show that increased endocrine cell abundance is due to altered Lgr5+ stem and Neurog3+ endocrine progenitor cell proliferation. Different from the intestine, calorie restriction decreased gastric Lgr5+ stem cells, while increasing a FOXO1/Neurog3+ subpopulation of endocrine progenitors in a Notch-dependent manner. Further, activation of FOXO1 was sufficient to promote endocrine cell differentiation independent of Notch. The Notch inhibitor PF-03084014 or ghrelin receptor antagonist GHRP-6 reversed the phenotypic effects of calorie restriction in mice. Tirzepatide additionally expanded ghrelin+ cells in mice. In summary, calorie restriction promotes Notch-dependent, FOXO1-regulated gastric endocrine cell differentiation.

BIG coordinates auxin and SHORT ROOT to promote asymmetric stem cell divisions in Arabidopsis roots.

KEY MESSAGE: BIG regulates ground tissue formative divisions by bridging the auxin gradient with SHR abundance in Arabidopsis roots. The formative divisions of cortex/endodermis initials (CEIs) and CEI daughter cells (CEIDs) in Arabidopsis roots are coordinately controlled by the longitudinal auxin gradient and the radial SHORT ROOT (SHR) abundance. However, the mechanism underlying this coordination remains poorly understood. In this study, we demonstrate that BIG regulates ground tissue formative divisions by bridging the auxin gradient with SHR abundance. Mutations in BIG gene repressed cell cycle progression, delaying the formative divisions within the ground tissues and impairing the establishment of endodermal and cortical identities. In addition, we uncovered auxin's suppressive effect on BIG expression, triggering CYCLIND6;1 (CYCD6;1) activation in an SHR-dependent fashion. Moreover, the degradation of RETINOBLASTOMA-RELATED (RBR) is jointly regulated by BIG and CYCD6;1. The loss of BIG function led to RBR protein accumulation, detrimentally impacting the SHR/SCARECROW (SCR) protein complex and the CEI/CEID formative divisions. Collectively, these findings shed light on a fundamental mechanism wherein BIG intricately coordinates the interplay between SHR/SCR and auxin, steering ground tissue patterning within Arabidopsis root tissue.

Enhancement of the chondrogenic differentiation capacity of human dental pulp stem cells via chondroitin sulfate-coated polycaprolactone-MWCNT nanofibers.

Most of the conditions involving cartilaginous tissues are irreversible and involve degenerative processes. The aim of the present study was to fabricate a biocompatible fibrous and film scaffolds using electrospinning and casting techniques to induce chondrogenic differentiation for possible application in cartilaginous tissue regeneration. Polycaprolactone (PCL) electrospun nanofibrous scaffolds and PCL film were fabricated and incorporated with multi-walled carbon nanotubes (MWCNTs). Thereafter, coating of chondroitin sulfate (CS) on the fibrous and film structures was applied to promote chondrogenic differentiation of human dental pulp stem cells (hDPSCs). First, the morphology, hydrophilicity and mechanical properties of the scaffolds were characterized by scanning electron microscopy (SEM), spectroscopic characterization, water contact angle measurements and tensile strength testing. Subsequently, the effects of the fabricated scaffolds on stimulating the proliferation of human dental pulp stem cells (hDPSCs) and inducing their chondrogenic differentiation were evaluated via electron microscopy, flow cytometry and RT‒PCR. The results of the study demonstrated that the different forms of the fabricated PCL-MWCNTs scaffolds analyzed demonstrated biocompatibility. The nanofilm structures demonstrated a higher rate of cellular proliferation, while the nanofibrous architecture of the scaffolds supported the cellular attachment and differentiation capacity of hDPSCs and was further enhanced with CS addition. In conclusion, the results of the present investigation highlighted the significance of this combination of parameters on the viability, proliferation and chondrogenic differentiation capacity of hDPSCs seeded on PCL-MWCNT scaffolds. This approach may be applied when designing PCL-based scaffolds for future cell-based therapeutic approaches developed for chondrogenic diseases.