Search Results (118)

Age-associated hair loss is primarily driven by decreased function and proliferation of hair follicle stem cells (HFSCs), often exacerbated by increased inhibitory signaling and changes in the stem cell niche. Macrophage polarization to the anti-inflammatory M2 phenotype is known to increase stem cell proliferation. We investigated the effects of poly-D,L-lactic acid (PDLLA) on hair growth in middle-aged skin, focusing on its role in modulating macrophage polarization and HFSC activity. Senescent macrophages were analyzed for Piezo1 activity, macrophage polarization, and secretion of hepatocyte growth factor (HGF) and insulin-like growth factor-1 (IGF-1) after PDLLA treatment. Downstream effects on HFSC proliferation, stemness, and Wnt signaling were assessed, including inhibition experiments using the Piezo1 blocker GsMTx4. In vivo analyses assessed hair follicle number, diameter, length, anagen duration, and hair coverage following PDLLA administration in middle-aged mice. PDLLA increased Piezo1 expression and activity in senescent macrophages, enhancing M2 polarization and secretion of HGF and IGF-1. This activated the RAS/ERK signaling pathway, promoting HFSC proliferation and stemness. Furthermore, PDLLA upregulated Wnt signaling molecules (Wnt3a, Wnt10b, and β-catenin) and anagen phase-related factor (Axin2, LEF1, and Lgr5), which were decreased by GsMTX4. In middle-aged animal skin, PDLLA administration led to increased hair follicle number, diameter, and length, as well as prolonged anagen and greater hair coverage. Collectively, these findings suggest that PDLLA rejuvenates the middle-aged skin microenvironment, at least in part through Piezo1-associated M2 macrophage polarization and enhanced HFSC function, offering a promising therapeutic strategy for age-related hair loss targeting both the immune and the stem cell compartments. Full article

This study investigated the potential of scale-up mango leaf extract (MLE) as a treatment for diabetes, a global public health concern. MLE was prepared by boiling in water, yielding 12.07% (w/w), with a bioactive mangiferin content of 165.67 ± 10.88 μg/g in the crude powder. Mechanistically, MLE demonstrated a hypoglycemic effect by stimulating glucagon-like peptide-1 (GLP-1) secretion in NCI-H716 L-cells. This occurred through activation of the MAPK signaling pathway, evidenced by increased p-ERK1/2, p-p38, and p-c-Jun expression, and the Wnt signaling pathway, shown by increased β-catenin and decreased GSK-3β and Axin1 expression, consistent with molecular docking. In a type 2 diabetic rat model, MLE administration (40 mg/kg) significantly reduced metabolic parameters, including fasting blood glucose (FBG), body weight, cholesterol (CHOL), triglycerides (TGs), and HbA1c. Notably, MLE lowered serum insulin and the HOMA-IR index, and reduced serum dipeptidyl peptidase-IV (DPP-IV) levels, resulting in increased serum GLP-1, comparable to the drug sitagliptin. These findings suggest that MLE has great potential to lower blood glucose by inducing GLP-1 secretion via MAPKs and Wnt signaling pathways, positioning it as a promising candidate for alternative diabetes treatment or development as a dietary supplement. Full article

Norrin–Wnt signaling is essential for retinal vascular development and generation of the inner blood retinal barrier. Norrin itself is a potential therapeutic for retinal vascular repair. We explored the feasibility of producing a recombinant protein therapeutic based on human Norrin for intravitreal injection. Norrin^K86P production was tested using MBP fusion and non-tagged versions. FZD4 binding was evaluated by an ELISA, and the activation of AXIN2 gene expression in primary human retinal microvascular endothelial cells was measured by qPCR. Intravitreal injection was tested in the rat eye, evaluated by fluoresceine angiography, OCT, and ERG. MBP-tagged Norrin was resistant to HRV3C protease cleavage unless linker polypeptides were also incorporated. MBP–Norrin or cleaved MBP–Norrin also required refolding with disulfide reshuffling to generate FZD4-binding activity and to affect AXIN-2 gene expression. A production strategy based upon untagged Norrin^K86P refolded from bacterial inclusion bodies was selected. Intravitreal injection of Norrin^K86P did not affect retinal thickness nor retinal function, the latter monitored by the ERG A-wave and B-wave amplitudes. We concluded that MBP–Norrin, cleaved Norrin, and untagged Norrin from inclusion bodies display Norrin-like biological activity after refolding with disulfide reshuffling. The untagged, bacterial inclusion body process was selected for future large-scale bacterial fermentation. Norrin^K86P could be produced with Norrin-like biochemical and biological activities and was tolerated after intravitreal injection into the rat eye. Full article

Background: Tooth development or odontogenesis is a complicated, multi-staged process, regulated by a plethora of genes. Disruptions during the early stages of odontogenesis may cause the complete absence of one or more teeth, known as tooth agenesis (TA). Except for PAX9, alterations in MSX1, AXIN2, WNT10A, and EDA/EDAR/EDARADD have gathered an increasing amount of interest. Objectives: This systematic review aims to investigate whether non-syndromic tooth agenesis (NSTA) is associated with MSX1, AXIN2, WNT10A, and EDA/EDAR/EDARADD mutations and to list the related phenotypic patterns of these alterations with regard to missing teeth. Methods: MEDLINE, Scopus, and Web of Science were the three selected databases. Duplicates were removed using Mendeley, and the records were assessed via the Rayyan platform. The Newcastle–Ottawa Scale was used to evaluate the quality of the evidence. Results: Fifteen case–control studies were eligible for this systematic review. The MSX1 gene was examined in most studies, whereas second premolars and lateral incisors were the most commonly missing teeth among TA cases. In total, 61.29% to 84.9% of the cases included one or two absent teeth. Conclusions: Due to the considerable heterogeneity in reporting results across the included studies, along with the high risk of bias present in most of them, it was not feasible to conduct a meta-analysis of the data. Nonetheless, the findings suggest that the NSTA phenotypes linked to the studied genes are similar to those associated with other forms of TA and share a common pattern of missing teeth. Future research should adopt a more standardized approach in presenting findings by adhering to established terminology and definitions and by utilizing common cut-off points to categorize results. Full article

Tooth agenesis (TA), the congenital absence of one or more teeth, is the most common manifestation of defective dental morphogenesis in humans. TA can occur as an isolated (non-syndromic) condition or as part of a broader syndromic presentation. In this review, we analyzed a total of 73 manuscripts to provide a comprehensive update on the genetic landscape of TA. To investigate the genes, variants, and associated phenotypes, we reviewed data from curated databases including Human Phenotype Ontology (HPO), OMIM, ClinVar and MalaCards. Based on the current evidence, the genes most frequently implicated in TA are MSX1, EDA, and PAX9. However, chromosomal abnormalities, such as those seen in Down syndrome and Williams syndrome, along with structural variations (e.g., deletions and duplications), also contribute significantly to TA etiology. The most involved pathways include TNF receptor binding, encompassing genes such as EDA, EDA2R, EDAR, and EDARADD, and the mTOR signaling pathway, which includes AXIN2, FGFR1, LRP6, WNT10A, and WNT10B. The aim of this review is to provide an critical synthesis of the genetic mechanisms underlying TA, highlighting the contribution of major signaling pathways, regulatory networks, and emerging molecular insights that may inform diagnostic and therapeutic advances. Full article

Neuromast cells are specialized mechanosensory receptor cells embedded within the lateral line system of aquatic vertebrates, enabling the detection of water movement and vibration that are essential for navigation, prey capture, and predator avoidance. These cells share common evolutionary and functional homology with mammalian inner ear hair cells, both of which rely on stereocilia-mediated mechano-transduction and ion channel activation to convert mechanical stimuli into neural signals. Unlike their mammalian counterparts, neuromast hair cells possess a regenerative capacity following damage, making the lateral line system a unique model for studying hair cell regeneration and sensory restoration. This study examines the potential of the Mexican tetra (Astyanax mexicanus) as a novel model organism for investigating ototoxicity and regeneration of neurosensory hair cells. Here, we explore the cranial and trunk lateral line neuromasts, including deep canal neuromast cells located in facial bones, such as the mandible and circumorbital bones. In the present study, juvenile surface-dwelling Mexican tetra were exposed to a 500 µM neomycin for 4 h to induce targeted hair cell damage. The samples were collected at 4-, 12-, 24-, and 72 h post-exposure. Furthermore, neuromast cell viability was assessed using [2-(4-(Dimethylamino) styryl)-N-ethylpyridinium iodide] (DASPEI). Gene expression analysis revealed a modest increase in Fibroblast Growth Factor 1 (fgf1) and Axis Inhibition Protein 2 (axin2) expression following treatment; however, these changes were not statistically significant. The SRY-box transcription factor 2 (sox2) remains constant throughout the exposure and recovery period. These findings highlighted the regenerative dynamics of neuromast cells in Mexican tetra. This work lays the foundation for future therapeutic strategies targeting human sensory deficits, particularly those involving inner ear hair cell degeneration. Full article

Background: Functional single ventricle (FSV) comprises a heterogeneous group of congenital heart diseases (CHDs) with severe and complex abnormalities. The multifactorial etiology of the disease poses challenges in identifying specific pathogenic factors and planning effective interventions and preventive treatments for patients. Methods: Whole-exome sequencing (WES) was performed to identify variants in relevant genes in 29 FSV patients from different families. Results: In total, 95 heterozygous variants across 48 CHD-associated genes were identified, including 85 missense, four small indel, one splicing, one stop gain, and four synonymous variants. Among them, 22 were novels, 11 conflicting, and four pathogenic variants. Each patient carried from two to six variants in different genes, including at least one variant in genes associated with serious heart defects such as AXIN1, BMP2, COL6A2, GATA4, GATA5, GDF1, MESP1, MYH6, NFATC1, NKX2-6, NOTCH1, PCSK9, TBX1, TBX18, and TBX20. In addition, the variants in the COL6A1, CREBBP, DOCK6, EOGT, EP300, LRP2, MYBPC3, MYH7, SEMA3C, and ZFPM2 genes are associated with characteristic phenotypes of FSV, such as atrial septal defect, ventricular septal defect, small left heart syndrome, transposition of the great arteries, and double outlet right ventricle occurring at high frequency in patients. The prediction results suggest that these are potentially pathogenic variants in patients and may explain the phenotype in patients. Conclusions: This is the first study to identify variants associated with functional single ventricle, a complex form of congenital heart disease. Our results contribute to a general understanding of the causes of the disease, thereby guiding treatment and prevention approaches for patients. Full article

Congenital hearing loss, frequently resulting from defective hair cells, remains poorly understood due to the incomplete identification of key pathogenic genes. Oncomodulin (OCM) is a kind of calcium-binding protein (CaBP) that regulates diverse cellular processes and is thought to play crucial roles in auditory function. In teleost fish, parvalbumin 8 (pvalb8) and parvalbumin 9 (pvalb9) belong to the oncomodulin lineage and are highly expressed in hair cells. In this study, we first reported the oncomodulin lineage function in fish and identified pvalb8 as an essential regulator of hair cell development. Single-cell RNA sequencing (scRNA-seq) and whole-mount in situ hybridization (WISH) revealed that pvalb8 is highly and specifically expressed in supporting cells and hair cells. Functional loss of pvalb8, achieved via CRISPR/Cas9 knockout or morpholino knockdown, resulted in reduced neuromast size and a significant decrease in neuromast hair cell number, leading to auditory behavioral deficits. In addition, pvalb9 mutants exhibited hair cell defects similar to those observed in pvalb8 mutants, including a significant reduction in hair cell number. Moreover, pvalb8 loss strongly inhibited the proliferation of supporting cells, which likely accounts for the reduced number of differentiated hair cells. The expression levels of Wnt target genes, axin2, ccnd1, and myca, were all significantly reduced in pvalb8 mutants compared to control zebrafish, while activation of the Wnt signaling pathway rescued the hair cell loss observed in pvalb8 mutants, indicating that pvalb8 promotes hair cell development via Wnt-dependent proliferative signaling. These findings highlight pvalb8 as a critical factor in the regulation of auditory hair cell formation and function in zebrafish, offering new insights into the role of oncomodulin lineage in sensory cell development. Full article

The Sterile alpha motif domain-containing protein 4 (SAMD4) family consists of two evolutionarily conserved and highly homologous RNA-binding proteins, SAMD4A and SAMD4B. Previous studies have established SAMD4A as a tumor suppressor that is downregulated in breast cancer, while the function of SAMD4B in tumorigenesis remains poorly defined. In this study, we observed that SAMD4B expression is upregulated in breast cancer. Functional assays demonstrated that SAMD4B facilitated breast cancer cell proliferation, migration, and invasion by inducing epithelial–mesenchymal transition (EMT). Furthermore, SAMD4B accelerated G1-to-S phase cell cycle progression by modulating p53 expression, collectively supporting an oncogenic function of SAMD4B in breast cancer. Mechanistically, we found that SAMD4B enhanced TCF/LEF transcriptional activity and upregulated the expression of β-catenin, Cyclin D1, c-Myc, and Axin2. Further investigations confirmed that SAMD4B activated the Wnt/β-catenin pathway by stabilizing β-catenin mRNA and increasing β-catenin protein expression level. Importantly, treatment with XAV-939, a specific Wnt/β-catenin pathway inhibitor, abrogated the pro-oncogenic effects of SAMD4B overexpression, including Wnt/β-catenin pathway activation, enhanced proliferation, and increased metastatic capacity. These results confirm that SAMD4B promotes the malignant phenotypes of breast cancer cells in a manner dependent on the Wnt/β-catenin pathway. In summary, our findings clarify that SAMD4B exerts an oncogenic role in breast cancer progression by activating the Wnt/β-catenin pathway. These data identify SAMD4B as a potential therapeutic target in breast cancer, although further in vivo investigations are required to validate its clinical relevance. Full article

Background/Objectives: Human ovarian granulosa cells (hGCs) are crucial to ovarian follicle development and function, exhibiting multipotency and the ability to differentiate into neuronal cells, chondrocytes, and osteoblasts in vitro. 3,4,5,4′-tetramethoxystilbene (DMU-212) is a methylated derivative of resveratrol, a natural polyphenol found in grapes and berries, with a wide spectrum of biological activities, including notable anticancer properties. Interestingly, DMU-212 exhibits cytotoxic effects predominantly on cancer cells while sparing non-cancerous ones, and evidence suggests that similar to resveratrol, it may also promote hGC differentiation. This study aimed to investigate the effects of the liposomal formulation of this methylated resveratrol analog—lipDMU-212—on the osteogenic differentiation ability of hGCs in a primary three-dimensional cell culture model. Methods: lipDMU-212 was formulated using the thin-film hydration method. GC spheroids’ viability was evaluated after exposure to lipDMU-212, an osteoinductive medium, or both. Osteogenic differentiation was confirmed using Alizarin Red staining and quantified by measuring Alkaline Phosphatase (ALP) activity on days 1, 7, and 15. RNA sequencing (RNA-seq) was performed to explore molecular mechanisms underlying lipDMU-212-induced differentiation. Results: lipDMU-212 promoted osteogenic differentiation of hGCs in the 3D cell culture model, as evidenced by increased mineralization and a ~4-fold increase in ALP activity compared with the control. RNA-seq revealed up-regulation of genes related to cell differentiation and cellular identity. Furthermore, JUN (+2.82, p = 0.003), LRP1 (+2.06, p = 0.05), AXIN1 (+3.02, p = 0.03), and FYN (+3.30, p = 0.01) were up-regulated, indicating modulation of the Wnt/β-catenin signaling pathway, a key regulator of osteoblast differentiation. Conclusions: The ability of GCs to differentiate into diverse tissue-specific cell types underscores their potential in regenerative medicine. This study contributes to the understanding of lipDMU-212’s role in osteogenic differentiation and highlights its potential in developing future therapies for degenerative bone diseases. Full article

The growth plate is a specialized cartilage structure near the ends of long bones that orchestrates longitudinal bone growth during fetal and postnatal stages. Within this region reside a dynamic population of growth plate skeletal stem cells (gpSSCs), primarily located in the resting zone, which possess self-renewal and multilineage differentiation capacity. Recent advances in cell-lineage tracing, single-cell transcriptomics, and in vivo functional studies have revealed distinct subpopulations of gpSSCs, which are defined by markers such as parathyroid hormone-related protein (PTHrP), CD73, axis inhibition protein 2 (Axin2), forkhead box protein A2 (FoxA2), and apolipoprotein E (ApoE). These stem cells interact intricately with their niche, particularly after the formation of the secondary ossification center, through stage-specific regulatory mechanisms involving several key signaling pathways. This review summarizes the current understanding of gpSSC identity, behavior, and regulation, focusing on how these cells sustain growth plate function through adapting to biomechanical and molecular cues. Full article

Adolescent idiopathic scoliosis (AIS) is a multifactorial disease with environmental and genetic components. AIS clinical management is complicated by the lack of reliable predictive markers of progression. Recent studies have highlighted a potential role for epigenetic mechanisms in disease progression. However, most findings derive from peripheral blood analyses, with little data available on musculoskeletal tissues directly affected by AIS. Given the tissue-specific nature of epigenetic regulation, validating blood-based biomarkers in disease-relevant tissues is essential. We performed a comparative multi-gene RT-qPCR analysis, arranged in a custom array format, to assess the local expression of candidate epigenetically regulated genes associated with AIS progression across bone, paravertebral muscle, spinal ligament, and peripheral blood, all collected from the same patients. Tissue- and gene-specific expression patterns were observed, supporting the presence of local regulatory mechanisms. Peripheral blood expression of HAS2, PCDH10, H19, ADIPOQ, ESR1, GREM1, SOX9, FRZB, LRP6, and FBN1 resembled bone expression, while PITX1, CRTC1, APC, CTNNB1, FZD1, and AXIN1 reflected muscle and ligament; WNT1 reflected only muscle. In contrast, GREM1 and SOX9 were expressed only in muscle and ligament and FGF4 and NPY only in muscle, suggesting limited systemic biomarker potential. Compared to non-AIS tissues, AIS samples showed downregulation of PCDH10 and FBN2 in bone and CRTC1, FRZB, LRP6, and MSTN in muscle. WNT1 and WNT10 were upregulated in muscle and FBN1 in ligament. In conclusion, the results highlight differential gene expression across AIS tissues, supporting tissue-specific regulation in some of the genes analyzed. Only a subset of markers exhibited blood expression patterns that reflected those in specific tissues, suggesting that certain blood biomarkers may act as surrogates for distinct tissue compartments. These results lay the groundwork for future DNA-based studies to confirm the epigenetic nature of this regulation and to identify reliable biomarkers for AIS progression. Full article

Wnt/β-catenin signaling is hyper-activated in several cancer cells and cancer stem cells. Dishevelled/Dvl is a key adapter protein that acts as a bridge between the Wnt receptor Frizzled (Fzd) and other cytosolic factors. In detail, the C-terminal cytosolic region is the ligand of the PSD-95, disks large, and zonula occludens-1 (PDZ) domain of Dvl. Therefore, the PDZ domain (Dvl-PDZ) is thought to be a potential drug target. In this paper, we determined the first crystal structure of the PDZ domain of human Dvl1 (hDvl1-PDZ) at a 2.4 Å resolution. The domain was adapted into a unique trimeric form in which all the canonical ligand-binding clefts were occupied by the β2-β3 loop of the neighbor molecule, like an auto-inhibiting trimer. We used solution nuclear magnetic resonance (NMR) experiments to assess the presence of the self-associated oligomer of hDvl1-PDZ in the solution. Introducing the Ala substitution at Asp 272, the key residue of the β2-β3 loop, partly abolished the concentration-dependent chemical shift change, which suggests that this residue is one of the key residues for formation. Based on these observations, we propose an auto-inhibiting trimer formation of Dvl-PDZ in a Dvl-Axin hetero-oligomerization model of Wnt/β-catenin signal transduction. Full article

Microbial symbioses play crucial roles in insect physiology, contributing to nutrition, detoxification, and metabolic adaptations. However, the microbial communities associated with the lac insect Llaveia axin axin, an economically significant species used in traditional lacquer production, remain poorly characterized. In this study, the bacterial diversity and community structure of L. axin axin were investigated using both culture-dependent and culture-independent (metagenomic) approaches, combined with fatty acid profile analysis. The insects were bred at the laboratory level, in controlled conditions, encompassing stages from eggs to adult females. Bacterial strains were isolated from bacteriomes and identified through 16S rRNA gene amplification and genomic fingerprinting through ARDRA analysis. Metagenomic DNA was sequenced using the Illumina MiSeq platform, and fatty acid profiles were determined by gas chromatography–mass spectrometry (GC-MS). A total of 20 bacterial strains were isolated, with Acinetobacter, Moraxella, Pseudomonas, and Staphylococcus detected in first-instar nymphs; Methylobacterium, Microbacterium, and Bacillus in pre-adult females; and Bacillus and Microbacterium in adults. Metagenomic analysis revealed key genera including Sodalis, Blattabacterium, and Candidatus Walczuchella, with Sodalis being predominant in early stages and Blattabacteriaceae in adults. Fatty acid analysis identified palmitic, oleic, linoleic, arachidic, and stearic acids, with stearic acid being the most abundant. These results suggest that dominant bacteria contribute to lipid biosynthesis and metabolic development in L. axin axin. Full article

Colorectal cancer (CRC) remains the second leading cause of cancer-related mortality worldwide, with aberrant activation of the Wnt/β-catenin signaling pathway constituting a key driver of tumorigenesis. SALL2, a zinc finger transcription factor deregulated in various cancers, has been implicated in Wnt signaling regulation through its Xenopus ortholog; however, its role in human CRC remains unclear. In this study, we investigated the expression and function of SALL2 in CRC. Immunohistochemical analysis revealed that SALL2 is present in the epithelium and stroma of normal colon tissue but is significantly downregulated in adenomas, carcinomas, and CRC cell lines. Reduced SALL2 expression was associated with elevated levels of active β-catenin and poorer overall patient survival. Functional assays demonstrated that SALL2 transcriptionally activates AXIN2, a key negative regulator of the Wnt/β-catenin pathway. Chromatin immunoprecipitation and promoter-reporter assays confirmed SALL2 binding to the AXIN2 proximal promoter and enhanced promoter activity. Furthermore, SALL2 expression potentiated the pro-apoptotic effects of the Wnt pathway inhibitor XAV939 in CRC cells, suggesting a role in sensitizing cells to Wnt-targeted therapies. Collectively, these findings identify SALL2 as a negative regulator of Wnt/β-catenin signaling and support its potential as a prognostic biomarker and therapeutic target in colorectal cancer. Full article