Search Results (233)

Introduction: The genus Thorichthys comprises nine species of Central American freshwater cichlids, which are distributed along the eastern slopes of Mexico and Honduras. These species are grouped into two subgroups: “helleri” and “meeki”. While some analyses of the group’s ecomorphology and character evolution have been conducted, the skeletal structures of this genus remain to be described. Objective: This study provides an osteological description of the species in the genus Thorichthys. Methodology: The specimens were sectioned and stained with alizarin red, and the bone structures were analyzed and described. Results: The genus Thorichthys possesses 12 abdominal vertebrae and 12–13 caudal vertebrae. Species of “helleri” group are characterized by the following points: (1) there is a urohyal bone with a sharply concave dorsal margin and a spiniform, inclined process; (2) typically, there are a total of 14–15 gill rakers in the first gill arch; (3) the opercular bone bears a dorsally displaced, posterior protuberance; (4) a total of 12–13 anal pterygiophores; and (5) a slightly recurved cephalic profile. Meanwhile species of the “meeki” group exhibit the following characteristics: (1) a urohyal with a broad, unsharpened dorsal concavity and a small, blunt, nearly straight process; (2) a total of 15–21 gill spines; (3) a dorsally positioned protuberance in the middle of the opercular bone; (4) a total of 14–16 proximal anal pterygiophores; and (5) a straight cephalic profile. Conclusions: These bony elements are proposed as a complement to the taxonomic differentiation of the species in Thorichthys, and to contribute new morphological characteristics to the study of other cichlid genera. Full article

The number of patients who require endoprosthetic treatment related to osteoporosis has increased in recent years. Vitamin D3 supplementation has long been standard practice in osteoporosis treatment, while vitamin K2 has gained importance. Using our in vitro model, we compared the osteogenic behaviour of primary healthy human osteoblasts (hOBs) and primary osteoporotic human osteoblasts (hopOBs) under unchanged conditions, with vitamin K2, vitamin D3 and the combined addition. Fluorescence microscopy examinations on a plastic surface and a rough titanium surface structure revealed morphological differences. A quantitative analysis of mineralisation and differentiation was performed using an alizarin red S assay and analysis of alkaline phosphatase activity. It was shown that the hopOBs behave differently morphologically on the titanium surface, while hopOBs are particularly noticeable due to the higher number of cell–cell interactions with vitamin K2. The rough surface led to more pronounced mineralisation of the hopOBs. This effect was pronounced under vitamin K2. Vitamin D3 had an effect in the initial phase of hopOB differentiation. Overall, vitamin K2 had a greater influence on the mineralisation of hopOBs than expected. It must be assumed that vitamin K2 plays a significantly greater role in the metabolism of hopOBs than previously assumed. Full article

Background/Objectives: A third-generation atypical antipsychotic drug, aripiprazole, is known to cross the placental barrier and pose negative consequences on placental growth and the normal development of the fetus. Although a few studies demonstrated these debilitating effects of aripiprazole, its skeletal effects remain unexplored. Therefore, this study was undertaken to evaluate the impact of prenatal aripiprazole exposure, administered at three different dose levels, on the ossification of the appendicular skeleton in 20-day-old rat fetuses. Methods: Forty pregnant Sprague–Dawley rats (n = 40) were assigned to four groups: control and three aripiprazole-treated groups receiving 3 mg/kg (LDA), 6 mg/kg (HDA), and 12 mg/kg (DHDA) daily from gestational days 6–19. Fetuses were delivered on gestation day 20, weighed, and processed for skeletal evaluation using Alizarin Red S staining. Ossification patterns of metacarpals, metatarsals, hip bones, long bones of the forelimb and hindlimbs from a total of 151 fetuses were analyzed and categorized as complete, delayed, or absent. Results: Aripiprazole exposure induced a dose-dependent reduction in the number of completely ossified skeletal bony centers (p < 0.01) with a highly significant reduction in the length of ossified portions of the long bones (p < 0.001). Histomorphometric analysis of Von Kossa-stained fetal femur sections revealed a significant decrease in the thickness of ossified cortical and trabecular bone with a statistically significant reduction in the length of hypertrophied chondrocytes of the growth plate cartilage in the aripiprazole-treated groups (p < 0.05). Conclusions: Prenatal exposure to aripiprazole leads to dose-dependent skeletal growth restriction and delayed ossification of the appendicular skeleton in rat fetuses. Future investigations should focus on the molecular mechanisms and consequences related to the prenatal impact of aripiprazole. Full article

Background and Objectives: Dental pulp stem cells (DPSCs) possess significant regenerative potential; however, oxidative stress impairs their viability and osteogenic differentiation. Gingerol, the principal bioactive component of ginger, exhibits antioxidant and cytoprotective properties. This study evaluated the protective effects of gingerol on DPSCs exposed to H₂O₂-induced oxidative stress. Materials and Methods: DPSCs isolated from extracted human teeth following Institutional Review Board approval and informed consent were exposed to H₂O₂-induced oxidative stress and treated with varying concentrations of gingerol. Cell viability, migration, osteogenic activity, mineralization, intracellular ROS accumulation, and Wnt/β-catenin signaling-related gene expression were evaluated using MTT, scratch wound healing assay, Alizarin Red S staining, ROS staining, ELISA, and real-time PCR. Results: Gingerol improved DPSC viability, migration, and mineralization under oxidative stress conditions. Increased ALP and BSP expression indicated enhanced osteogenic activity, while reduced ROS accumulation suggested attenuation of oxidative injury. Gingerol also modulated MMP-2 and MMP-9 expression and normalized oxidative stress-associated alterations in inflammatory and Wnt/β-catenin signaling-related gene expression. Conclusions: Gingerol demonstrated protective effects against oxidative stress-induced dysfunction in DPSCs and supported osteogenic differentiation. These findings suggest that gingerol may serve as a supportive bioactive candidate for regenerative dental applications; however, further mechanistic and in vivo studies are required to confirm its therapeutic potential. Full article

Bone marrow-derived mesenchymal stem cells (BMSCs) maintain skeletal homeostasis by balancing adipogenic and osteogenic differentiation, yet clinically used drugs that bias this fate choice and their mechanisms remain incompletely defined. Here, we investigated whether dextromethorphan (DXM), a widely used antitussive, modulated lineage commitment in rat BMSCs and interrogated candidate upstream signaling modules. Rat BMSCs were induced with adipogenic medium or osteogenic medium in the presence of DXM (30 μM). Adipogenesis and osteogenesis were quantified using Oil Red O and Alizarin Red S staining with elution-based quantification, and lineage markers were measured by RT-qPCR. Intracellular Ca²⁺ and ROS were analyzed using flow cytometry, and the levels of p-AKT and p-ERK were assessed through Western blotting analysis. Under adipogenic induction, DXM increased lipid droplet accumulation and the mRNA levels of Pparγ and Fabp4. Although DXM elevated Ca²⁺ and ROS, the chelation of intracellular Ca²⁺ and pharmacological inhibition of Sig-1R/PLC–IP3R signaling, redox/ROS, NMDA receptors, AKT/ERK, Kv channels, bitter taste receptor-related signaling, and mTOR did not attenuate the DXM-enhanced adipogenesis. DXM reduced p-ERK without increasing p-AKT; U0126 lowered basal adipogenesis but did not block the DXM effect. Under osteogenic induction, DXM reduced matrix mineralization and downregulated Runx2 and Bglap mRNA levels, while Wwtr1 mRNA levels were not significantly changed. DXM also partially reversed the osteogenic induction-associated reduction in Mtor mRNA. Separately, under adipogenic induction, rapamycin attenuated baseline adipogenesis but did not prevent the additional lipid accumulation induced by DXM. Collectively, DXM shifted the osteogenic–adipogenic balance toward adipogenesis through a non-canonical mechanism. Full article

Orthodontic tooth movement (OTM) is driven by force-induced alveolar bone remodeling, yet the molecular mechanisms by which periodontal ligament stem cells (PDLSCs) sense and transduce mechanical signals remain incompletely understood. Here, we identify the epigenetic regulator HELLS as a compressive force-responsive gene and investigate its role as a mechanosensitive mediator in human PDLSCs (hPDLSCs). Compressive force downregulated HELLS expression both in vitro and in a mouse OTM model. Functionally, siRNA-mediated HELLS knockdown impaired osteogenic differentiation, as evidenced by reduced Alizarin Red S staining and alkaline phosphatase activity, and induced global transcriptomic changes indicative of altered mechanotransduction pathways. Moreover, HELLS knockdown increased YAP and RANKL expression and potentiated osteoclast differentiation of co-cultured RAW264.7 cells. Finally, we identified E2F1 as a candidate transcription factor mediating the force-induced downregulation of HELLS. Collectively, these findings establish HELLS as a potential mechano-epigenetic regulator in hPDLSCs, and suggest that its force-induced downregulation may contribute to alveolar bone remodeling during OTM by simultaneously attenuating osteogenesis and enhancing pro-osteoclastogenic signaling via transcriptional reprogramming. Full article

Vascular calcification is an actively regulated process driven by vascular smooth muscle cell (VSMC) osteogenic reprogramming and promoted by oxidative stress and extracellular matrix remodeling. We investigated whether the novel histone deacetylase inhibitor YAK577 mitigates calcification by modulating an MMP14–NOX2/ROS-associated pathway in calcification medium (CM)-treated VSMCs and a vitamin D₃-induced arterial calcification model in 8-week-old male C57BL/6N mice. Calcification was assessed by Alizarin Red S/von Kossa staining and calcium quantification; osteogenic markers (BMP2, RUNX2, MSX2) and MMPs were examined by qRT-PCR and immunoblotting; intracellular ROS was measured by DHE staining with N-acetylcysteine as an antioxidant control; and MMP14 was manipulated by siRNA knockdown or plasmid overexpression. YAK577 was non-cytotoxic at effective concentrations and reduced CM-induced calcium deposition and osteogenic marker expression. YAK577 reduced MMP14 expression and suppressed CM-induced NOX2/p47phox activation and ROS accumulation, while GSK2795039 attenuated CM-induced DHE fluorescence. MMP14 silencing attenuated, whereas MMP14 overexpression enhanced, osteogenic signaling and increased NOX2. In vivo, YAK577 reduced vitamin D₃-induced aortic calcium burden, histological calcification, and the expression of MMP14, NOX2, and osteogenic markers. These data support a working model in which YAK577 alleviates vascular calcification, at least in part, by suppressing an MMP14-associated NOX2/p47phox–ROS axis. Full article

The aim of this study was to evaluate the biological effects of bioactive glass-containing self-adhesive resin cements (SARCs) on human dental pulp stem cells (DPSCs), focusing on cytocompatibility, odontogenic differentiation, and mineralization. Experimental SARCs containing 0–5 wt% BAG (BG0–BG5) were compared with two commercially available SARCs, RelyX U200 and TheraCem. Eluates were prepared and applied to DPSCs for the methylthiazol tetrazolium (MTT) assay, quantitative real-time polymerase chain reaction (qRT-PCR), immunofluorescence (IF) staining, and Alizarin Red S (ARS) staining. The result showed there were no significant differences in cell viability across all groups (p > 0.05), indicating that the addition of BAG did not affect cell viability, while the early odontogenic differentiation markers, such as RUNX2, ALP, and COL1A1, showed no clear trend among the groups. However, late-stage markers (DMP-1 and DSPP) were significantly higher in the BG2–BG5 groups relative to the OM group (p < 0.05). IF staining revealed intense signals in the BG2–BG5 groups (p < 0.05) and also ARS staining showed a time-dependent increase in mineral deposition. Within the limitations of this study, BAG-containing SARCs do not negatively impact cytocompatibility and promote late-stage odontogenic differentiation and mineral deposition. Full article

Bone regeneration requires tight coordination between mesenchymal stem cells (MSCs), immune signaling, and extracellular matrix remodeling. Yet, how atypical immune receptors contribute to this process remains unclear. Here, we identify Toll-like receptor 10 (TLR10) as a key regulator of osteogenic differentiation in human adipose-derived MSCs. Herein, ASC/TERT1 MSCs were engineered to overexpress or silence TLR10 using lentiviral vectors, and osteogenic differentiation (0–14 days) was assessed by metabolic assays—RT-qPCR of COL1A2, ALPL and BGLAP—Alizarin Red S staining, and quantitative mass spectrometry. Enhancing TLR10 expression promoted osteogenic gene programs, extracellular matrix organization, metabolic adaptation, and robust matrix mineralization, whereas TLR10 suppression maintained proliferative states and impaired osteoblast maturation. Proteomic analyses revealed that TLR10 selectively activates osteogenic, ECM-remodeling, and vitamin D-responsive pathways, while restraining programs antagonistic to differentiation. Notably, active vitamin D induced TLR10 expression and partially restored osteogenesis in TLR10-deficient cells, indicating that TLR10 is associated with vitamin D-driven bone formation. Together, beyond its established role in innate immunity, TLR10 emerges as a vitamin D-responsive regulator of mesenchymal stem cell osteogenesis, highlighting a potential therapeutic axis to enhance bone regeneration and osteogenic outcomes. Full article

Bone defects have become a leading cause of disability and mortality. The pro-inflammatory state and impaired vascularization are major factors hindering bone defect repair. However, current bone regeneration materials lack the ability to regulate the osteoimmune microenvironment and promote vascularized bone regeneration. In this study, we employed clinically used fat emulsion (FE), which is intravenously administered to provide nutrition and energy for patients, to investigate the effect of immunomodulation on promoting angiogenesis and osteogenesis. Results from RT-qPCR analysis and immunofluorescence staining demonstrated that FE exhibited potent anti-inflammatory effects by reducing the expression of the pro-inflammatory marker inducible nitric oxide synthase (iNOS) and upregulating the expression of the anti-inflammatory marker transforming growth factor-beta (TGF-β). Endothelial tube formation and scratch assays demonstrated that FE promoted angiogenesis and cell migration by releasing vascular endothelial growth factor (VEGF) within the inflammatory microenvironment. Alkaline phosphatase (ALP) and alizarin red S (ARS) staining revealed that FE facilitated ALP activity and calcium nodule formation by releasing bone morphogenetic protein-2 (BMP-2) within the inflammatory microenvironment. These findings may prove promising and cost-effective for the clinical treatment of bone defects. Full article

In this study, a novel material was obtained by functionalizing shredded maize stalk (MS) with Alizarine Red S (ArS), a complexing agent that contains −OH and −C=O groups in its structure (MS-ArS). The obtained MS-ArS was employed in adsorption studies for Mn²⁺, Pb²⁺, Cu²⁺, Cr³⁺, Zn²⁺, and Fe³⁺ (Mⁿ⁺) removal from mixed aqueous matrices. Initially, complex formation between (Mⁿ⁺) and ArS in buffer solution at pH 4 and 10 was investigated using the UV-Vis spectrometric method. Continuous, the functionalization process of MS with ArS was tested at several pH values (2, 4, 6, 8, and 10) using a batch technique. It was observed that the best functionalization of MS with ArS was obtained at pH = 2. Subsequently, Mⁿ⁺ adsorption onto the MS-ArS mass was tested separately at pH 4 and 10. The study achieved that Mⁿ⁺ adsorption proved to be pH dependent. The results confirmed that at pH = 10, Mⁿ⁺ adsorption was increased, compared with pH = 4. MS-ArS has affinity for Mⁿ⁺ in the following order Fe³⁺ > Cu²⁺ > Zn²⁺ > Mn²⁺ > Pb²⁺ > Cr³⁺. Experimental data revealed remarkable desorption rates when 0.5 M HCl was used. After five adsorption/desorption cycles of Mⁿ⁺, the removal capability of MS-ArS was preserved. Overall, the potential of MS-ArS for effective Mⁿ⁺ removal/reuse makes it a sustainable polymer for wastewater treatment applications. Full article

Background/Objectives: Endodontic sealers can interact with periapical tissues through extrusion, yet the molecular mechanisms underlying their biological effects remain poorly defined. This study investigated how commonly used sealers influence mitogen-activated protein kinase (MAPK) signaling, cell viability, and osteogenic-associated responses in MC3T3-E1 pre-osteoblasts. Methods: Four commercial sealers, Calcium-silicate-based Bioceramic Sealer (EndoSequence^® BC Sealer, BC), Zinc oxide eugenol sealer (Kerr Pulp Canal Sealer, ZOE), Sealapex™, and AH26^®, were applied as standardized pellets, allowed to set, and cultured with MC3T3-E1 cells. Calcium deposition was assessed by Alizarin Red S (ARS) staining, and MAPK activation was evaluated by Western blotting. Due to excessive solubility (Sealapex™) or poor cell survival (AH26^®), mechanistic analyses were performed only for BC and ZOE. Osteogenic-associated gene expression was measured by qRT-PCR, and the functional role of MAPK signaling was assessed using ERK, JNK, and p38 inhibitors. Results: BC and Sealapex™ produced robust ARS staining, while ZOE and AH26^® produced minimal mineral-associated staining. Both BC and ZOE activated ERK, JNK, and p38, with ZOE inducing higher phosphorylation. However, BC maintained greater cell viability and increased Runx2 and Osx expression, whereas ZOE impaired early cell attachment and viability. MAPK inhibition in BC-treated cultures reduced osteogenic-associated gene expression and ARS staining, indicating MAPK involvement in BC-mediated responses. Conclusions: BC and ZOE elicit distinct MAPK activation patterns and cellular responses. Under the conditions tested, BC promoted a more favorable osteogenic-associated response, whereas ZOE compromised early cell viability. These mechanistic insights may help explain clinical differences in periapical tissue responses to sealer extrusion. Full article

Developing novel anabolic agents for bone regeneration remains a clinical priority. Polydeoxyribonucleotide (PDRN) exhibits tissue-regenerative properties, but its direct cellular effects on bone remodeling remain unclear. This in vitro study investigated PDRN’s effects on osteoblast (MC3T3-E1) and osteoclast (primary bone marrow-derived macrophages) differentiation. We evaluated metabolic activity, gene/protein expression, and specific differentiation markers using MTS, qRT-PCR, Western blotting, and functional assays (ALP, Alizarin Red S, TRAP, pit formation). In osteoblasts, PDRN dose-dependently modulated metabolic activity while upregulating the early transcription factor Runx2. PDRN significantly enhanced osteoblast differentiation, evidenced by increased ALP activity, elevated mineralized matrix deposition, and robust upregulation of osteocalcin and Runx2. Conversely, PDRN exhibited no direct effect on osteoclast precursor metabolic activity, differentiation, or resorptive function. These findings support a working hypothesis in which PDRN selectively promotes osteoblast differentiation without directly affecting osteoclastogenesis. While further pharmacological investigations are required to definitively elucidate the specific purinergic receptor mechanisms, our results highlight PDRN as a promising candidate anabolic agent for bone regeneration. Full article

Background: Bone remodeling depends on the dynamic balance between osteoclast-mediated bone resorption and osteoblast-mediated bone formation. Follistatin-like 1 (FSTL1) has been reported as an osteoclast-secreted protein that inhibits osteoclast differentiation, but its direct effects on osteoblast differentiation remain unclear. This study aimed to determine whether FSTL1 regulates osteoblast differentiation and mesenchymal stem cell migration and characterizes its role in osteoclast-osteoblast cellular cross-talk under in vitro conditions. Methods: Bone marrow-derived macrophages (BMMs) and stromal cells (BMSCs) from mice were used to induce osteoclast and osteoblast differentiation, respectively. Chemotaxis was assessed by Transwell migration, and osteoblast differentiation was evaluated in BMSC and MC3T3-E1 cells using staining, qRT-PCR, Western blotting, and proliferation assays. Results: FSTL1 significantly suppressed osteoclast differentiation and resorptive activity, confirmed by TRAP staining and pit assay, respectively. Expression of osteoclast markers such as NFATc1, TRAP, and DC-STAMP was reduced under FSTL1 treatment. In BMSCs, FSTL1 did not affect proliferation but significantly enhanced chemotaxis. Moreover, FSTL1 promoted osteogenic differentiation and mineralization, as demonstrated by increased ALP activity and Alizarin Red S staining. In MC3T3-E1 pre-osteoblasts, FSTL1 increased cell proliferation and mineralization by MTS and Alizarin Red staining. Key osteogenic markers, including Runx2 and osteocalcin, were also upregulated. Conclusions: Osteoclast-derived FSTL1 significantly suppresses osteoclastogenesis and promotes mesenchymal cell chemotaxis and osteogenic differentiation, indicating a role in regulating osteoclast–osteoblast cellular interactions in vitro. Targeting FSTL1 signaling may represent a promising therapeutic strategy for osteoporosis and other disorders of impaired bone remodeling. Full article

Background/Objectives: Cells derived from direct chemical reprogramming into osteoblasts represent a promising source for bone regeneration, but the efficiency needs improvement. Here, we systematically evaluated whether the natural compound psoralen (Psr) could enhance this process and explored its therapeutic potential and mechanism of action. Methods: Mouse embryonic fibroblasts (MEFs) were treated with a cocktail of forskolin and phenamil (FP), supplemented with Psr. In vitro differentiation was assessed by alkaline phosphatase and Alizarin Red S staining, reverse transcription quantitative PCR, immunofluorescence and Western blot. The bone-regenerative potential of the derived chemically induced osteoblast-like cells (ciOBs) was evaluated in critical-sized calvarial defects, femoral cortical defects and a subcutaneous ectopic implantation model, using micro-computed tomography and histology. Mechanistic insights of Psr were gained by analyzing the adenylyl cyclase 9 (ADCY9)/cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA)/cAMP response element-binding protein (CREB) axis using inhibitor SQ22536. Results: Psr acted synergistically with the FP cocktail to drive efficient osteogenic reprogramming of MEFs. At an optimal concentration of 25 μM, Psr enabled the most robust induction of early osteogenic markers and generation of mature, mineralizing ciOBs in vitro. In vivo, FP + Psr-induced ciOBs repaired critical-sized calvarial and femoral cortical defects and generated substantial, vascularized bone tissue in ectopic sites. Mechanistically, Psr co-treatment potently activated the ADCY9/cAMP/PKA/CREB pathway, and pharmacological inhibition of this pathway completely abolished the pro-osteogenic effects of Psr. Conclusions: Psr acts as a potent synergistic enhancer of direct chemical reprogramming, generating functional osteoblast-like cells with robust bone-regenerative capacity via activation of the ADCY9/cAMP/PKA/CREB pathway. Full article