Search Results (226)

Objectives: Pilose antler protein extract (PAE) was investigated for its therapeutic efficacy against ovariectomy (OVX)-induced osteoporosis and its underlying molecular mechanism. Methods: An OVX rat model was established to evaluate the effects of PAE on bone microarchitecture, histopathological changes, and bone metabolism-related parameters. Bone structure was assessed using Micro-CT and histological analysis, and biochemical and bone turnover markers were quantified. In vitro, Mouse calvarial pre-osteoblast subclone 14 (MC3T3-E1) Subclone 14 cells were used to examine the effects of PAE on cell viability, proliferation, osteogenic differentiation, and osteogenesis-related protein expression. Results: High-dose PAE markedly improved trabecular bone microarchitecture in OVX rats, as reflected by increased bone surface area and bone volume fraction and reduced trabecular separation. PAE significantly enhanced bone calcium content and elevated serum Bone Morphogenetic Protein 2 (BMP-2) and Procollagen Type I N-Terminal Propeptide (PINP) levels, while decreasing serum Alkaline Phosphatase (ALP) activity and C-Terminal Telopeptide of Type I Collagen (CTX-I) levels, indicating a shift toward bone formation. Mechanistically, PAE activated the Wnt-3a/β-Catenin signaling pathway in bone tissue and MC3T3-E1 cells, as evidenced by increased expression of Wnt-3a and β-Catenin proteins. In vitro experiments further demonstrated that PAE promoted MC3T3-E1 cell proliferation and upregulated osteogenic markers, i.e., Runt-related transcription factor 2 (RUNX2) and Osteocalcin (OCN). Conclusions: Collectively, these findings suggest that PAE exerts pronounced anti-osteoporotic effects and is associated with activation of the Wnt/β-Catenin signaling pathway. Full article

Treatment for large critical-sized bone defects and impaired fracture healing remain challenging. Clinically used protein-based osteoinductive factors, such as recombinant bone morphogenetic proteins (BMPs), can be effective; however, they are costly and limited by stability, dose-delivery issues, and safety concerns. Preclinical small molecules offer an alternative because they are chemically stable, scalable to manufacture, and readily integrated for systemic administration or localized release from scaffolds, hydrogels, cements, and implant coatings. With an emphasis on delivery formats and mechanistic themes, this review examines small molecules that have been shown to improve bone regeneration in preclinical models, contrasting those of biological origin with synthetic and repurposed compounds. Across studies, these selected compounds promote osteoblast commitment, differentiation, and matrix mineralization via BMP/Smad signaling and Wnt/beta-catenin (β-catenin) activation, often through glycogen synthase kinase-3 beta (GSK-3β) inhibition or relief of pathway antagonism or Hedgehog (Hh) pathway stimulation. Beyond osteoinduction, several candidates address issues that commonly limit repair, including angiogenesis, oxidative stress, inflammatory tone, osteoimmune regulation, and suppression of osteoclast-mediated resorption. Direct head-to-head comparisons are rare across both classes and reporting heterogeneity complicates interpretation. Key translational gaps include limited cytotoxicity and immunologic profiling, dose and release optimization, durability of benefit, and insufficient evaluation of rational combinations. More rigorous in vivo studies, including larger animal models and standardized outcome metrics, are needed to prioritize promising candidates and guide clinical development. Full article

Skin and its appendages form an integrated system of ectodermal mini-organs that rely on Wnt signaling for lifelong homeostasis and regeneration; yet, the pathway operates in a highly organ-specific manner in each compartment. In interfollicular epidermis, the Wnt activity is spatially graded, thus maintaining the balance between basal progenitor proliferation and terminal differentiation. The hair follicle is governed by an intrinsic oscillator based on cross-regulation between Wnt and BMP signaling, providing a cell-autonomous layer of control over hair cycle dynamics. Finally, the nail organ is characterized by the spatial compartmentalization of Wnt activity, with a distal matrix activation zone supported by specialized mesenchymal niche cells that sustain continuous nail plate growth and coordinate the digit tip regeneration. Understanding these divergent regulatory architectures provides a conceptual framework for targeted regenerative strategies aimed at enhancing repair in skin and its appendages. Therefore, in this review, we synthesize recent molecular studies on Wnt signaling in the adult skin, hair follicles, and nail mini-organs, highlighting appendage-specific features that underlie their distinct regenerative capacities. We further discuss how dysregulated Wnt signaling contributes to skin, hair, and nail pathologies such as alopecia, chronic wounds, excessive scarring, skin cancer, and nail deformations, and summarize the emerging strategies that target Wnt pathway to therapeutically enhance hair regrowth, wound repair, cancer treatment, and digit tip regeneration. Full article

Tooth development or odontogenesis is a complex morphogenetic process that requires tightly regulated interactions between the oral epithelium and mesenchyme of neural crest origin. In this narrative review, we compile existing knowledge regarding gene regulatory networks and epigenetic factors throughout tooth development from initiation to eruption. Signaling between the epithelium and mesenchyme is mediated by four conserved pathways—Wnt/β-catenin, bone morphogenetic protein (BMP), fibroblast growth factor (FGF), and Sonic hedgehog (Shh)—which operate iteratively and interact through extensive crosstalk at each developmental stage. Transcription factors, such as PAX9, MSX1, PITX2, and LEF1, interpret these signals to control cell fate decisions and differentiation. Epigenetic modifications, including DNA methylation, histone modifications, and microRNA-mediated regulation, provide additional layers of control that fine-tune gene expression programs. Unlike existing reviews that address these regulatory mechanisms separately, here we integrate signaling pathways, transcription factor networks, epigenetic regulation, human genetic disorders, dental stem cell biology, and recent single-cell transcriptomic insights into a unified framework. We discuss opportunities to apply developmental biology knowledge towards regenerative dentistry goals, including iPSC-derived dental models and spatially resolved multi-omics approaches, while acknowledging the considerable gap between preclinical findings and clinical applications. Full article

Skin and hair follicles regenerate through coordinated stem cell niches and cyclic signaling associated with transitions among anagen, catagen, and telogen phases. In alopecia and chronic skin diseases, follicular miniaturization, immune dysregulation, persistent inflammation, impaired vascularization, and a compromised stratum corneum barrier limit the effectiveness of conventional topical and systemic therapies. Bio-nanovesicles (BNVs), including natural extracellular vesicles such as exosomes and microvesicles, as well as engineered artificial or hybrid nanovesicles, offer a targeted, cell-free delivery platform for miRNAs, proteins, and growth factors. By modulating key pathways—Wnt/β-catenin, PI3K/AKT, MAPK/ERK, and TGF-β/BMP—BNVs have the potential to restore regenerative crosstalk, enhance angiogenesis, and help initiate hair and skin repair. Full article

Background/Objectives: Dihydroartemisinin (DHA), a bioactive metabolite of Artemisia annua, displays potent antitumor activity in multiple cancers. However, its dose-dependent transcriptional regulatory networks in colorectal cancer (CRC) remain insufficiently understood. This study aimed to clarify the molecular mechanisms of low- and high-dose DHA in human CRC cells and reveal the dose-dependent crosstalk among related biological processes. Methods: We integrated RNA-seq transcriptomic profiling and functional validation in HCT116 cells treated with 20 μM (low-dose) or 50 μM (high-dose) DHA. Differentially expressed genes (DEGs) were screened at FDR ≤ 0.05 and |log₂(fold change)| ≥ 1, followed by GO and KEGG enrichment analyses. Results: DHA inhibited cell viability dose-dependently, with an IC₅₀ of 50 μM. We identified 280 and 678 DEGs in low-and high-dose groups, respectively. Low-dose DHA induced apoptosis via GADD45α/β and ATF4/DDIT3-mediated endoplasmic reticulum stress and triggered senescence through G2/M phase arrest. High-dose DHA mainly modulated gene expression signatures associated with ferroptosis by regulating iron homeostasis and lipid peroxidation at the transcriptional level. Both doses suppressed glycolysis, lipid, and folate metabolism; high-dose DHA also inhibited MGAT5B-mediated glycosylation. DHA regulated five core signaling pathways dose-dependently, with high-dose DHA further repressing Wnt3a/16 and BMP4/6. Conclusions: This study first identifies ferroptosis-related gene networks as key transcriptional targets. It reveals dose-dependent crosstalk among cell death, senescence, metabolic reprogramming, and signaling, providing a transcriptomic framework and gene targets for optimizing DHA-based colorectal cancer therapy. Full article

Calcific aortic valve disease (CAVD) is an active pathological process driven by complex cellular and molecular mechanisms rather than passive aging. The disease is characterized by endothelial dysfunction, lipid infiltration, inflammation, extracellular matrix remodeling, and osteogenic differentiation of valvular interstitial cells, ultimately leading to hydroxyapatite deposition and progressive valve calcification. Key signaling pathways, including Notch, Wnt/β-catenin, BMP2, and TGF-β, play critical roles in osteogenic reprogramming, while inflammatory cytokines such as IL-6, IL-1β, and TNF-α contribute to a pro-calcific microenvironment. To summarize current knowledge on CAVD pathophysiology and emerging therapeutic strategies, relevant preclinical studies were identified through searches of PubMed, and clinical trials were identified through ClinicalTrials.gov. Evidence indicates that extracellular matrix remodeling, fibrosis, and dysregulated phosphate metabolism, particularly involving TNAP and DPP-4, further accelerate disease progression. Despite advances in understanding disease mechanisms, effective pharmacological therapies remain limited, with the current treatment largely restricted to valve replacement. Emerging therapeutic approaches targeting molecular pathways, including enzyme inhibition, RNA-based therapeutics, and advanced drug delivery systems, may offer promising strategies for disease modification. A deeper understanding of CAVD pathophysiology may facilitate the development of targeted therapies to delay or prevent disease progression. Full article

Background/Objectives: Congenital anomalies of the kidney and urinary tract (CAKUTs) represent the leading cause of pediatric chronic kidney disease, yet the molecular mechanisms underlying these malformations remain incompletely understood. While genetic studies have identified numerous CAKUT-associated genes, conventional knockout approaches often result in embryonic lethality or fail to reveal tissue-specific gene functions. This review aims to synthesize findings from conditional knockout mouse studies that have elucidated the spatiotemporal requirements of key signaling pathways during kidney development. Methods: We conducted a narrative synthesis of studies employing Cre-loxP conditional gene targeting in mouse models, identified through systematic searches of PubMed and cross-referencing of key primary research. Studies were selected based on their use of lineage-specific Cre drivers (Six2-Cre, Hoxb7-Cre, Foxd1-Cre) to investigate nephron progenitor maintenance, ureteric bud branching morphogenesis, and stromal–epithelial interactions. Results: Conditional knockout studies have redefined CAKUT pathogenesis as a disorder of dose-dependent signaling, temporal regulation, and inter-compartmental communication. WNT/β-catenin signaling operates in a biphasic, dose-dependent manner in nephron progenitors, with Six2-Cre-mediated β-catenin deletion causing premature progenitor depletion. BMP and FGF pathways demonstrate dose-dependent and context-specific functions in progenitor maintenance, while GDNF/RET signaling is essential for ureteric bud outgrowth and branching. Importantly, stromal-specific deletions have uncovered non-cell-autonomous mechanisms regulating nephron formation. Haploinsufficiency studies demonstrate that partial pathway disruption can reduce nephron endowment without overt CAKUT, predisposing to adult-onset hypertension and chronic kidney disease. Conclusions: Conditional gene targeting has mechanistically redefined CAKUT from a collection of structural malformations to a spectrum of disorders arising from quantitative perturbations in lineage-specific signaling networks. These findings establish that phenotypic severity is determined by the degree of pathway disruption, the developmental timing of insult, and the compartment affected, providing a framework for interpreting oligogenic interactions and variable penetrance in human CAKUTs. Full article

This study aimed to evaluate the mRNA and protein levels of SMURF1 and SMURF2 in breast cancer and to elucidate their potential biological roles through in silico analyses. Tumor and adjacent normal tissue samples were collected from 30 newly diagnosed breast cancer patients who underwent mastectomy. The mRNA expression levels of SMURF1 and SMURF2 were analyzed by quantitative PCR (qPCR), and their protein expression patterns were evaluated using immunohistochemistry (IHC). In addition, protein–protein interaction (PPI) and functional enrichment analyses were performed via the STRING database to identify potential molecular interactions and biological pathways associated with these genes. The mRNA expression level of SMURF1 was significantly downregulated in tumor tissues compared to normal breast tissues (p = 0.002), whereas no significant difference was observed in SMURF2 mRNA expression (p = 0.981). IHC results revealed that SMURF1 and SMURF2 protein levels did not differ significantly between tumor and normal samples. The in silico analysis demonstrated that SMURF1 and SMURF2 interact with multiple proteins involved in key signaling pathways, particularly the TGF-β/BMP and Wnt/β-catenin pathways. The findings suggest that the downregulation of SMURF1 in breast cancer may contribute to tumor progression by enhancing Wnt/β-catenin signaling activity. The interactions of SMURF1 and SMURF2 with TGF-β/BMP pathway regulators indicate that these genes may play dual roles in both tumor-suppressive and oncogenic mechanisms, depending on the cellular context. Full article

The vertebrate respiratory system arose under evolutionary pressures that linked increasing atmospheric oxygen levels to the metabolic demands of mitochondria. This transition—from ancestral gill-based exchange to the highly alveolated mammalian lung—was accompanied by the emergence of a hormonal regulatory axis centered on the glucocorticoid receptor alpha (GRα). Over time, GRα became deeply integrated into the architecture and function of the respiratory system, aligning pulmonary performance with organismal homeostasis across different developmental stages, environmental challenges, and disease states. This review combines evolutionary, embryological, and molecular evidence to explain how GRα shapes respiratory structure and function. We trace the evolution from ancient oxygen-sensing systems to mammalian alveoli and endothelial adaptations, demonstrating how conserved developmental pathways (including WNT, FGF, BMP, and SHH) are repurposed during both organogenesis and repair. Genetic models show that GRα is essential for preparing the lung for postnatal life, coordinating the reciprocal signaling between mesenchyme and epithelium that drives branching, septation, extracellular matrix organization, and the development of functional alveolar units. In the mature lung, GRα maintains the stability of the alveolar–capillary interface and coordinates immune, vascular, and metabolic functions to support efficient gas exchange. Its actions also extend to red blood cell biology and the regulation of stress erythropoiesis, linking pulmonary oxygen management with systemic oxygen delivery. Mechanistically, GRα interacts with circadian and hypoxia pathways and activates mitochondrial programs that enhance energy production and redox homeostasis during stress. By integrating these regulatory layers across developmental and physiological contexts, this review reframes GRα not simply as a stress-response receptor but as a non-redundant system-level integrator of respiratory homeostasis. Understanding this layered control not only explains the benefits of antenatal corticosteroids but also highlights the therapeutic value of phase-specific, precision modulation of the GC–GRα axis—along with strategies that support GC–GR signaling—to reestablishing and maintaining homeostasis in acute and chronic pulmonary disorders. Full article

Osteoporosis is a prevalent metabolic bone disorder characterized by reduced bone mass, compromised microarchitecture, and increased fracture risk. Its pathogenesis extends beyond simple bone mineral density (BMD) loss and reflects complex disruptions in bone remodeling governed by osteoblast–osteoclast coupling and systemic metabolic factors. This review lays particular emphasis on diabetes mellitus-related osteoporosis (DOP) and estrogen deficiency-induced osteoporosis (EDOP), discussing bone remodeling between osteoclastogenesis and osteoblast differentiation regulated by key signaling pathways, including the RANKL/RANK/OPG, Wnt/β-catenin, BMP–Smad, Hedgehog, and inflammatory cytokine networks. This review then explores how chronic hyperglycemia, insulin deficiency or resistance, oxidative stress, ferroptosis, advanced glycation end products, and low-grade inflammation disrupt bone homeostasis in diabetes, resulting in impaired bone quality and elevated fracture risk, particularly in type 2 diabetes. In parallel, we discuss the genomic and non-genomic actions of estrogen in maintaining skeletal integrity and elucidate how estrogen deficiency accelerates bone resorption and suppresses bone formation through altered cytokine signaling, oxidative stress, and impaired mechanotransduction. Advances in diagnostic strategies beyond BMD, including trabecular bone score, high-resolution peripheral quantitative computed tomography, and emerging biomarkers, are reviewed. Finally, this review summarizes current and emerging therapeutic approaches tailored to DOP and EDOP, emphasizing the need for mechanism-based, individualized management. A deeper understanding of these shared and distinct pathways may facilitate improved risk stratification and the development of targeted interventions for osteoporosis. Full article

The mechanisms driving the crown-to-root transition in tooth development remain incompletely understood, particularly the functional heterogeneity of dental epithelium. To address this gap and deconstruct this complexity, we aimed to analyze dental epithelial heterogeneity during this critical transition and to identify subpopulation-specific programs relevant to root development. We therefore established a single-cell transcriptomic atlas of the mouse molar at postnatal days 3.5 and 7.5, integrating 30,951 cells to profile the pan-tissue landscape and performing an in-depth analysis of 4323 dental epithelial cells. Our results reveal that the dental epithelium is composed of seven distinct subpopulations with a clear lineage hierarchy, originating from multipotent progenitors and bifurcating into self-renewing and differentiating trajectories. The identified particular functions of each subcluster include the following: structural maintaining progenitor that inhibits mineralization (Cluster 4), proliferation driver (Cluster 0), key signaling center (Cluster 1), terminally differentiated executing enamel formation (Cluster 3 and Cluster 6), and extracellular matrix-organizing hub (Cluster 5), communicating extensively via the Bmp, Tgf-β, and Wnt pathways. Our work defines dental epithelium as a dynamic and heterogeneous orchestrator of root morphogenesis, providing a foundational framework for understanding developmental biology and pioneering future regenerative strategies based on precise epithelial cell functions. Full article

Skin development undergoes significant molecular changes during early life stages in mammals. This study investigated transcriptomic differences in skin tissues between newborn (Y0) and one-year-old (Y1) Dezhou donkey foals using RNA-sequencing technology. Skin samples were collected from 13 Dezhou donkeys (7 newborns and 6 one-year-olds) and subjected to transcriptome analysis using the Illumina NovaSeq 6000 platform. A total of 133.66 Gb of clean data was obtained, yielding 252,342 transcripts and 204,683 unigenes. Differential expression analysis revealed 9878 significantly differentially expressed genes (DEGs) between age groups, with 4252 up-regulated and 5626 down-regulated genes in Y1 compared to Y0. Functional enrichment analysis identified key pathways, including ECM–receptor interaction, PI3K-Akt signaling, WNT signaling, and TGF-β signaling pathways. Notable findings included up-regulation of keratin genes (KRT1) and WNT family genes (WNT3, WNT4, WNT5, WNT6, WNT7, WNT10) in one-year-old foals, while collagen genes (COL1A, COL4A, COL5AS) and TGF-β signaling components (TGFB2, TGFB3, BMP5) were down-regulated. These results suggest that skin maturation involves enhanced barrier function, hair follicle development, and reduced collagen synthesis rates, providing insights into mammalian skin development mechanisms and potential applications in veterinary medicine and comparative biology. Full article

Long bone formation in vertebrates proceeds via endochondral ossification, a sequential process that begins with mesenchymal condensation, advances through cartilage anlage formation, and culminates in its replacement by mineralized bone. Recent advances in inducible lineage tracing and single-cell genomics have revealed that, rather than being a uniform event, mesenchymal condensation rapidly segregates into progenitor pools with distinct fates. Centrally located Sox9⁺/Fgfr3⁺ chondroprogenitors expand into the growth plate and metaphyseal stroma, peripheral Hes1⁺ boundary cells refine condensation via asymmetric division, and outer-layer Dlx5⁺ perichondrial cells generate the bone collar and cortical bone. Concurrently, dorsoventral polarity established by Wnt7a–Lmx1b and En1 ensures that dorsal progenitors retain positional identity throughout development. These lineage divergences integrate with signaling networks, including the Ihh–PTHrP, FGF, BMPs, and WNT/β-catenin networks, which impose temporal control over chondrocyte proliferation, hypertrophy, and vascular invasion. Perturbations in these programs, exemplified by mutations in Fgfr3, Sox9, and Dlx5, underlie region-specific skeletal dysplasias, such as achondroplasia, campomelic dysplasia, and split-hand/foot malformation, demonstrating the lasting impacts of embryonic patterning errors. Based on these insights, regenerative strategies are increasingly drawing upon developmental principles, with organoid cultures recapitulating ossification centers, biomimetic hydrogels engineered for spatiotemporal morphogen delivery, and stem cell- or exosome-based therapies harnessing developmental microRNA networks. By bridging developmental biology with biomaterials science, these approaches provide both a roadmap to unravel skeletal disorders and a blueprint for next-generation therapies to reconstruct functional bones with the precision of the embryonic blueprint. Full article

Cervical cancer remains a significant global health burden, with chemoradioresistance representing a major obstacle to successful treatment. To elucidate the mechanisms underlying this resistance, we established a unique pair of isogenic primary cervical cancer cell lines, AdMer35 and AdMer43, obtained from a patient with squamous cell carcinoma of the cervix before and after radiation therapy. The aim of our study was to characterize the transcriptomic and cellular heterogeneity of these cells. We conducted an in-depth comparative analysis using single-cell RNA sequencing. Analysis of this paired, patient-derived isogenic model suggests that chemoradioresistance can arise through coordinated multilevel cellular adaptations. Resistant AdMer43 cells demonstrated transcriptional reprogramming, with the upregulation of embryonic stemness factors (HOX, POU5F1, SOX2), a shift in extracellular matrix from fibrillar to non-fibrillar collagens, and activation of inflammatory pathways. We identified and characterized critical cell-state dynamics: resistant cells exhibited a remodeled ecosystem with a metabolically reprogrammed senescent-like cell population showing an enhanced pro-tumorigenic communication via EREG, SEMA3C, BMP, and WNT pathways. Furthermore, we identified a progenitor-like cell population with a minimal CNV burden, potentially serving as a reservoir for tumor persistence. These findings offer novel insights for developing targeted strategies to eliminate resistant cell pools and improve cervical cancer outcomes. Full article