Tooth morphogenesis is orchestrated by a complex interplay of signaling pathways and transcription factors that control cell proliferation, apoptosis, and differentiation, with the Wnt/β-catenin signaling pathway playing a pivotal role. However, the comprehensive regulatory mechanisms of Wnt/β-catenin signaling remain largely unclear. Smad7, a key antagonist of the TGF-β superfamily, is essential for maintaining tissue homeostasis and ensuring proper cellular function. Our previous study has demonstrated that Smad7 knockout in mice leads to impaired proliferative property of tooth germ cells, resulting in small molars. Here, we identified SMAD7 expression in human dental papilla and dental pulp, colocalized with β-CATENIN and cell proliferation-related proteins. RNA sequencing analysis revealed a significant reduction in Wnt signaling activity in Smad7-deficient mouse tooth germs. Using lentivirus transfection, we established SMAD7-knockdown human dental papilla stem cells, which manifested remarkably blunt proliferation rate, along with diminished Wnt signaling activity. In vivo transplantation investigations further revealed the indispensable role of SMAD7 in dentin formation. Mechanistically, we revealed that β-CATENIN interacts with P-SMAD2/3 and SMAD7 through co-immunoprecipitation and yeast two-hybrid assays. Inhibition of TGF-β pathway or disruption of SMAD7/β-CATENIN transcription factor complex formation potently impacted Wnt/β-catenin activities, indicating both direct and indirect regulatory mechanisms. These findings highlight the critical role of SMAD7 in the proliferation and differentiation of human dental stem cells, which could contribute to dental tissue regeneration and engineering.

Regeneration of the dentin-pulp complex is essential for tooth integrity and function. However, the inherent cell heterogeneity limits our understanding of lineage-specific subsets critical for efficient odontogenesis and regenerative outcomes. Here, we demonstrated that CD24+ human dental papilla cells (hDPCs) exhibit robust odontogenic differentiation capacity and drive coordinated regeneration of well-vascularized pulp and structurally integrated dentin tissues in both ectopic murine and preclinical in situ minipig models, significantly outperforming conventional dental pulp stem cells. Mechanistically, we delineate a BMP2/SIRT1 axis where elevated BMP signaling sustains SIRT1 expression and promotes mitochondrial metabolism and odontogenic capacity. Furthermore, BMP signaling induces VEGF expression, enhancing neovascularization via paracrine effects. CD24 is also a downstream marker of BMP signaling, though it does not directly mediate differentiation. Together, CD24+ hDPCs represent a regeneration-competent subpopulation that integrates mitochondrial metabolism and signaling crosstalk to enable coordinated dentin-pulp regeneration, representing a translationally relevant cell source for dental tissue engineering.

Abstract Beige adipocytes that emerge during the peri-weaning period support sympathetic nervous system (SNS)-independent thermogenesis, yet the mechanisms governing this spontaneous beiging remain unclear. Here, by integrating transcriptomic profiling with adipocyte-targeted Ctnnb1 deletion in mice, we identify the canonical Wnt signaling as an endogenous brake on developmental beige thermogenesis. Peri-weaning inguinal fat from adipocyte Ctnnb1 knockout mice exhibits enhanced beige adipocyte biogenesis, with increased thermogenesis-related gene expression and mitochondrial oxidative capacity, which programs durable activation of adaptive thermogenesis and augmented whole-body energy expenditure into adulthood. Mechanistically, suppression of Wnt/β-catenin signaling induces a non-canonical Wnt5a-Ca 2 ⁺-AMPK axis that promotes triglyceride lipolysis and subsequent PPAR-driven fatty acid oxidation, thereby fueling mitochondrial respiration. Genetic or pharmacological disruption of this axis blunts thermogenic responses induced by β-catenin inhibition in both murine and human subcutaneous adipocytes, indicating that Wnt5a-Ca 2 ⁺-AMPK axis is required for the cell-autonomous activation of beige fat. These results reveal Wnt/β-catenin signaling as a developmental constraint on beige adipocyte formation and suggest an SNS-independent route to sustainably raise energy expenditure and improve metabolic health.

Bone and skeletal muscle are essential components of musculoskeletal system, enabling movement, load-bearing, and systemic homeostasis. These tissues communicate through dynamic bone-muscle crosstalk mediated by cytokines, growth factors, and extracellular-matrix (ECM) proteins. The spatial organization of these mediators is critical for maintaining tissue integrity, and its disruption contributes to diseases, such as osteoporosis, sarcopenia, and metabolic syndrome. Despite this importance, spatial transcriptomics (ST) studies of bone-muscle interactions remain limited. Here, we applied 10x Genomics Visium ST with computational tools, e.g., SMART and CellChat, to deconvolute cell-type composition and characterize cell-cell communication networks and ligand-receptor (L-R) interactions in mouse femur and adjacent skeletal muscle. We identified eight major cell types (erythroid cells, endothelial cells, skeletal muscle cells, osteoblasts, myeloid cells, monocytes/macrophages, mesenchymal stem cells, and adipocytes) with distinct spatial transcriptional profiles and thirteen CellChat-inferred pathways, such as ECM-receptor related (e.g., COLLAGEN, TENASCIN, THBS) and secreted-signaling involved (e.g., VEGF) pathways. Representative L-R pairs include Col1a1/Col1a2-Sdc4, mediating osteoblast-to-muscle interactions, and Col4a1-Sdc4, facilitating muscle-to-osteoblast interactions in COLLAGEN, Tnxb-Sdc4 in TENASCIN, supporting muscle-to-osteoblast/muscle/myeloid/endothelial communication, Comp-Sdc4 in THBS, driving monocyte/macrophage-to-osteoblast/muscle signaling, and Vegfa-Vegfr1/Vegfr2 in VEGF, mediating muscle-to-endothelial/myeloid signaling. Immunostaining validated colocalization of several representative L-R pairs with their corresponding cells. Additionally, independent mouse and human bone scRNA-seq datasets reproduced most of the pathways and L-R pairs identified in ST, underscoring the robustness and cross-species relevance of our findings. Together, we present an initial spatially resolved transcriptome-wide map of bone-muscle intercellular communication, providing novel insights into molecular crosstalk and establishing groundwork for future studies in musculoskeletal disorders.

During homeostasis, osteocyte apoptosis is typically associated with bone loss through enhanced osteoclast recruitment and bone resorption. However, whether apoptotic osteocytes also regulate bone formation remains elusive. Here we report that conditional deletion of Mdm2, an E3 ubiquitin ligase regulating cell survival, causes osteocyte apoptosis but paradoxically results in a marked increase in bone mass attributed to up-regulated osteogenic activity. Single-cell RNA sequencing reveals enhanced osteoblastic differentiation of bone marrow mesenchymal stem cells (BMSCs) in conditional knockout mice, with enrichment of cellular calcium related pathways. Mechanistically, apoptotic vesicles (apovs) from Mdm2-deleted osteocytes are engulfed by BMSCs. TRPM8, a calcium channel protein, is enriched in osteocyte-derived apovs and transported into BMSCs, thereby promoting osteoblastic differentiation. Additionally, pharmacological inhibition of TRPM8 attenuates the high bone mass phenotype in conditional knockout mice. Therefore, Mdm2 deletion in osteocytes leads to osteocyte apoptosis, which enhances bone formation through communicating with BMSCs via TRPM8-enriched apovs. Our findings underscore the pivotal role of osteocytes in bone homeostasis and unveil a previously unrecognized mechanism whereby osteocyte apoptosis stimulates osteogenesis through affecting the fate of BMSCs in a TRPM8-mediated paracrine mechanism.

Bone and skeletal muscle are essential components of the musculoskeletal system, enabling movement, load-bearing, and systemic regulation. These tissues communicate through dynamic bone-muscle crosstalk mediated by cytokines, growth factors, and extracellular matrix (ECM) proteins. The spatial organization of these mediators is critical to maintaining tissue integrity, and disruptions contribute to diseases such as osteoporosis, sarcopenia, and metabolic syndrome. Despite the importance of spatial context, studies using spatial transcriptomics (ST) to investigate bone-muscle interactions remain limited. Here, we applied 10X Genomics Visium ST profiling and advanced computational tools to characterize cell-cell communication networks and ligand-receptor (L-R) interactions in mouse femur and adjacent skeletal muscle. We identified eight major cell types: erythroid cells, endothelial cells, skeletal muscle cells, osteoblasts, myeloid cells, monocytes/macrophages, mesenchymal stem cells, and adipocytes, each exhibiting distinct spatial gene expression profiles. Signaling pathway analysis revealed 13 key pathways mediating intra- and inter-tissue communication, including COLLAGEN, THBS, VEGF, FN1, and TENASCIN. Notable L-R pairs involved in bone, muscle, and bone-muscle crosstalk include Col1a2-Sdc4 (osteoblast-ECM interactions), Tnxb-Sdc4 (muscle-to-endothelial signaling), Vegfa-Vegfr1 and Vegfa-Vegfr2 (muscle-to-endothelial/myeloid signaling), and Comp-Sdc4 (monocyte/macrophage-to-osteoblast signaling). This study presents the first spatially resolved map of cell-cell communication across bone and skeletal muscle, providing novel insights into their molecular crosstalk. These findings offer a critical foundation for future therapeutic strategies targeting musculoskeletal disorders.

Bone is a multifaceted tissue requiring orchestrated interplays of diverse cells within specialized microenvironments. Although significant progress has been made in understanding cellular and molecular mechanisms of component cells of bone, revealing their spatial organization and interactions in native bone tissue microenvironment is crucial for advancing precision medicine, as they govern fundamental signaling pathways and functional dependencies among various bone cells. In this study, we present the first integrative high-resolution map of human bone and bone marrow, using spatial and single-cell transcriptomics profiling from femoral tissue. This multi-modal approach discovered a novel bone formation-specialized niche enriched with osteoblastic lineage cells and fibroblasts and unveiled critical cell-cell communications and co-localization patterns between osteoblastic lineage cells and other cells. Furthermore, we discovered a novel spatial gradient of cellular composition, gene expression and signaling pathway activities radiating from the trabecular bone. This comprehensive atlas delineates the intricate bone cellular architecture and illuminates key molecular processes and dependencies among cells that coordinate bone metabolism. In sum, our study provides an essential reference for the field of bone biology and lays the foundation for advanced mechanistic studies and precision medicine approaches in bone-related disorders.

While both Primary Age-Related Tauopathy (PART) and Alzheimer's Disease (AD) involve the accumulation of hyperphosphorylated tau (pTau)-positive neurofibrillary tangles (NFTs) in the hippocampus, PART is distinguished by the absence of β-amyloid (Aβ) deposition and is generally associated with milder cognitive impairment than AD. To delineate cellular and molecular mechanisms that are common or uniquely linked to disease progression in PART and AD, we constructed a transcriptome-wide, high-resolution atlas of the human hippocampus using samples from six individuals spanning the aged control (AC), PART, and AD groups. Our results supported that PART represent a precursor stage of AD, as evidenced by the altered transcriptional profiles of excitatory neurons (Exc) in the PART group, which exhibited a markedly increased capacity to promote Aβ production compared to both AC and AD groups. While the microglia (Mic) were reactivated in the PART group, this response was reduced in AD samples despite the presence of Aβ deposition, and appeared to further induce NFTs formation as a loop consequently driving the progression from PART to AD. Furthermore, subregion interactions in the signalling pathways related to neuronal survival and the maintenance of blood-brain-barrier (BBB) integrity were decreasing in the PART and disrupted in the AD groups, compared to the AC group. Additionally, we found a P53 signalling-related gene, TP53INP2, was uniquely upregulated in astrocytes near large vessels in AD. This suggests a potential mechanism of vessel-induced neuronal apoptosis in AD, a feature absent in AC and PART. In summary, our study offers new insights into the relationship between PART and AD, along with the molecular mechanisms driving the transition from PART to AD. Furthermore, we identified key molecular pathways associated with BBB disruption and vascular-associated neuronal degradation in AD which were absent in PART. These findings deepen our understanding of AD pathogenesis and may inform the development of targeted therapeutic strategies.

Aging increases the risk for Alzheimer’s disease (AD), driving pathological changes like amyloid-β (Aβ) buildup, inflammation, and oxidative stress, especially in the prefrontal cortex (PFC). We present the first subcellular-resolution spatial transcriptome atlas of the human prefrontal cortex (PFC), generated with Stereo-seq from six male AD cases at varying neuropathological stages and six age-matched male controls. Our analyses revealed distinct transcriptional alterations across PFC layers, highlighted disruptions in laminar structure, and exposed AD-related shifts in layer-to-layer and cell-cell interactions. Notably, we identified genes highly upregulated in stressed neurons and nearby glial cells, where AD diminished stress-response interactions that promote Aβ clearance. Further, cell-type-specific co-expression analysis highlighted three neuronal modules linked to neuroprotection, protein dephosphorylation, and Aβ regulation, with all modules downregulated as AD progresses. We identified ZNF460 as a transcription factor regulating these modules, offering a potential therapeutic target. In summary, this spatial transcriptome atlas provides valuable insight into AD’s molecular mechanisms. Aging increases the risk for Alzheimer’s disease (AD). Here, the authors present a spatial transcriptome atlas of the human prefrontal cortex in AD, revealing distinct transcriptional alterations.

The canonical bone morphogenetic protein (BMP) signaling pathway plays a crucial regulatory role in tooth development by activating Smad proteins to regulate gene expression. We previously identified an atypical canonical BMP signaling in dental mesenchyme that is Smad4-independent but Smad1/5-dependent. This study demonstrates that phosphorylated Smad1/5 (pSmad1/5) and Smad4 regulate distinct gene sets in murine dental mesenchyme. Real-time monitoring of BMP-Smad transcriptional activity revealed that Smad4-dependent canonical BMP signaling is restricted to neurovascular cells surrounding the condensed dental mesenchymal cells where pSmad1/5 is present. Notably, pSmad1/5 in dental mesenchymal cells form complexes with pSmad3 to prevent canonical BMP signaling. CUT&RUN assays revealed genome-wide co-occupancy of pSmad1/5 and pSmad3, indicating their function as transcriptional regulation units. Integrative analyses demonstrated that this atypical canonical BMP signaling regulates tooth sensory innervation and maintains odontogenic inductive potential in dental mesenchyme, enabling the identification of crucial genes for maintaining tooth inductive capability. Our findings elucidate the operating mechanism of atypical canonical BMP signaling in dental mesenchymal cells and clarify how BMP-Smad signaling exerts diverse functions across different cell types, informing future tooth bioengineering strategies.

Aging significantly elevates the risk for Alzheimer’s disease (AD), contributing to the accumulation of AD pathologies, such as amyloid-β (Aβ), inflammation, and oxidative stress. The human prefrontal cortex (PFC) is highly vulnerable to the impacts of both aging and AD. Unveiling and understanding the molecular alterations in PFC associated with normal aging (NA) and AD is essential for elucidating the mechanisms of AD progression and developing novel therapeutics for this devastating disease. In this study, for the first time, we employed a cutting-edge spatial transcriptome platform, SpaTial Enhanced Resolution Omics-sequencing (Stereo-seq), to generate the first comprehensive, subcellular resolution spatial transcriptome atlas of the PFC from six AD cases at various neuropathological stages and six age, sex, and ethnicity matched controls. Our analyses revealed distinct transcriptional alterations across six neocortex layers, highlighted the AD-associated disruptions in laminar architecture, and identified changes in layer-to-layer interactions as AD progresses. Further, throughout the progression from NA to various stages of AD, we discovered specific genes that were significantly upregulated in neurons experiencing high stress and in nearby non-neuronal cells, compared to cells distant from the source of stress. Notably, the cell-cell interactions between the neurons under the high stress and adjacent glial cells that promote Aβ clearance and neuroprotection were diminished in AD in response to stressors compared to NA. Through cell-type specific gene co-expression analysis, we identified three modules in excitatory and inhibitory neurons associated with neuronal protection, protein dephosphorylation, and negative regulation of Aβ plaque formation. These modules negatively correlated with AD progression, indicating a reduced capacity for toxic substance clearance in AD subject samples. Moreover, we have discovered a novel transcription factor, ZNF460, that regulates all three modules, establishing it as a potential new therapeutic target for AD. Overall, utilizing the latest spatial transcriptome platform, our study developed the first transcriptome-wide atlas with subcellular resolution for assessing the molecular alterations in the human PFC due to AD. This atlas sheds light on the potential mechanisms underlying the progression from NA to AD.

Regeneration of the dentin-pulp complex is essential for the lifelong structural integrity and biological function of damaged teeth. However, the inherent heterogeneity of dental stem cells limits our understanding of lineage-specific subsets critical for efficient odontogenesis and regenerative outcomes. Here, we identify a distinct subpopulation of human dental papilla cells (hDPCs) marked by CD24 expression. CD24+ hDPCs exhibit robust odontogenic differentiation capacity, preferential localization in odontoblast-generating regions during tooth development, and accumulation beneath reparative dentin in carious teeth. Functionally, CD24+ hDPCs drive coordinated regeneration of well-vascularized pulp and structurally integrated dentin tissues in both ectopic murine and preclinical in situ minipig models, significantly outperforming conventional dental pulp stem cells. Mechanistically, we delineate a BMP2-driven metabolic axis where elevated BMP signaling sustains SIRT1 expression and promotes mitochondrial metabolism. Inhibition of BMP signaling disrupts this axis, resulting in WNT signaling activation, reduced SIRT1 expression, compromised antioxidant and autophagic responses, and consequently diminished odontogenic capacity. Furthermore, BMP signaling in CD24+ hDPCs induces VEGF expression, which enhances endothelial cell recruitment and neovascularization via paracrine effects. CD24 is also a downstream marker of odontogenic BMP signaling, reflecting BMP pathway activation and correlating with odontogenic potential, though it does not directly mediate differentiation. Together, our findings characterize CD24+ hDPCs as a regeneration-competent subpopulation that integrates mitochondrial metabolism and signaling crosstalk to enable coordinated dentin and pulp regeneration, representing a translationally relevant cell source for dental tissue engineering.

Bone morphogenetic protein (BMP)-Smad1/5/8 signaling plays a crucial regulatory role in lung development and adult lung homeostasis. However, it remains elusive whether BMP-Smad1/5/8 signaling is involved in the pathogenesis of emphysema. In this study, we downregulated BMP-Smad1/5/8 signaling by overexpressing its antagonist Noggin in adult mouse alveolar type II epithelial cells (AT2s), resulting in an emphysematous phenotype mimicking the typical pathological features of human emphysema, including distal airspace enlargement, pulmonary inflammation, extracellular matrix remodeling, and impaired lung function. Dysregulation of BMP-Smad1/5/8 signaling in AT2s leads to inflammatory destruction dominated by macrophage infiltration, associated with reduced secretion of surfactant proteins and inhibition of AT2 proliferation and differentiation. Reactivation of BMP-Smad1/5/8 signaling by genetics or chemotherapy significantly attenuated the morphology and pathophysiology of emphysema and improved the lung function in Noggin-overexpressing lungs. We also found that BMP-Smad1/5/8 signaling was downregulated in cigarette smoke-induced emphysema, and that enhancing its activity in AT2s prevented or even reversed emphysema in the mouse model. Our data suggest that BMP-Smad1/5/8 signaling, located at the top of the signaling cascade that regulates lung homeostasis, represents a key molecular regulator of alveolar stem cell secretory and regenerative function, and could serve as a potential target for future prevention and treatment of pulmonary emphysema.(c) 2023 The Pathological Society of Great Britain and Ireland.

Aging significantly elevates the risk for Alzheimer's disease (AD), contributing to the accumulation of AD pathologies, such as amyloid-β (Aβ), inflammation, and oxidative stress. The human prefrontal cortex (PFC) is highly vulnerable to the impacts of both aging and AD. Unveiling and understanding the molecular alterations in PFC associated with normal aging (NA) and AD is essential for elucidating the mechanisms of AD progression and developing novel therapeutics for this devastating disease. In this study, for the first time, we employed a cutting-edge spatial transcriptome platform, STOmics® SpaTial Enhanced Resolution Omics-sequencing (Stereo-seq), to generate the first comprehensive, subcellular resolution spatial transcriptome atlas of the human PFC from six AD cases at various neuropathological stages and six age, sex, and ethnicity matched controls. Our analyses revealed distinct transcriptional alterations across six neocortex layers, highlighted the AD-associated disruptions in laminar architecture, and identified changes in layer-to-layer interactions as AD progresses. Further, throughout the progression from NA to various stages of AD, we discovered specific genes that were significantly upregulated in neurons experiencing high stress and in nearby non-neuronal cells, compared to cells distant from the source of stress. Notably, the cell-cell interactions between the neurons under the high stress and adjacent glial cells that promote Aβ clearance and neuroprotection were diminished in AD in response to stressors compared to NA. Through cell-type specific gene co-expression analysis, we identified three modules in excitatory and inhibitory neurons associated with neuronal protection, protein dephosphorylation, and negative regulation of Aβ plaque formation. These modules negatively correlated with AD progression, indicating a reduced capacity for toxic substance clearance in AD subject samples. Moreover, we have discovered a novel transcription factor, ZNF460, that regulates all three modules, establishing it as a potential new therapeutic target for AD. Overall, utilizing the latest spatial transcriptome platform, our study developed the first transcriptome-wide atlas with subcellular resolution for assessing the molecular alterations in the human PFC due to AD. This atlas sheds light on the potential mechanisms underlying the progression from NA to AD.

Shox2 plays a vital role in the morphogenesis and physiological function of the sinoatrial node (SAN), the primary cardiac pacemaker, manifested by the formation of a hypoplastic SAN and failed differentiation of pacemaker cells in Shox2 mutants. Shox2 and Nkx2-5 are co-expressed in the developing SAN and regulate the fate of the pacemaker cells through a Shox2-Nkx2-5 antagonistic mechanism. Here we show that simultaneous inactivation of Nkx2-5 in the SAN of Shox2 mutants (dKO) rescued the pacemaking cell fate but not the hypoplastic defects, indicating uncoupling of SAN cell fate determination and morphogenesis. Single-cell RNA-seq revealed that the presumptive SAN cells of Shox2-/- mutants failed to activate pacemaking program but remained in a progenitor state preceding working myocardium, while both wildtype and dKO SAN cells displayed normal pacemaking cell fate with similar cellular state. Shox2 thus acts as a safeguard but not a determinant to ensure the pacemaking cell fate through the Shox2-Nkx2-5 antagonistic mechanism, which is segregated from its morphogenetic regulatory function in SAN development.

Hertwig's epithelial root sheath (HERS) interacts with dental apical mesenchyme and guides development of the tooth root, which is integral to the function of the whole tooth. However, the key genes in HERS essential for root development are understudied. Here, we show that Axin1, a scaffold protein that negatively regulates canonical Wnt signaling, is strongly expressed in the HERS. Axin1 ablation in the HERS of mice leads to defective root development, but in a manner independent of canonical Wnt signaling. Further studies reveal that Axin1 in the HERS negatively regulates the AKT1-mTORC1 pathway through binding to AKT1, leading to inhibition of ribosomal biogenesis and mRNA translation. Sonic hedgehog (Shh) protein, a morphogen essential for root development, is over-synthesized by upregulated mTORC1 activity upon Axin1 inactivation. Importantly, either haploinsufficiency of the mTORC1 subunit Rptor or pharmacological inhibition of Shh signaling can rescue the root defects in Axin1 mutant mice. Collectively, our data suggest that, independently of canonical Wnt signaling, Axin1 controls ribosomal biogenesis and selective mRNA translation programs via AKT1-mTORC1 signaling during tooth root development.

Although enhanced fibroblast growth factor (FGF) signaling has been demonstrated to be crucial in many cases of syndromic cleft palate caused by tongue malposition in humans, animal models that recapitulate this phenotype are limited, and the precise mechanisms remain elusive. Mutations in FGF9 with the effect of either loss- or gain-of-function effects have been identified to be associated with cleft palate in humans. Here, we generated a mouse model with a transgenic Fgf9 allele specifically activated in cranial neural crest cells, aiming to elucidate the gain-of-function effects of Fgf9 in palatogenesis. We observed cleft palate with 100% penetrance in mutant mice. Further analysis demonstrated that no inherent defects in the morphogenic competence of palatal shelves could be found, but a passively lifted tongue prevented the elevation of palatal shelves, leading to the cleft palate. This tongue malposition was induced by posterior spatial confinement that was exerted by temporomandibular joint (TMJ) dysplasia characterized by a reduction in Sox9+ progenitors within the condyle and a structural decrease in the posterior dimension of the lower jaw. Our findings highlight the critical role of excessive FGF signaling in disrupting spatial coordination during palate development and suggest a potential association between palatal shelf elevation and early TMJ development.

Adipose-derived stem cells (ADSCs) have emerged as a promising resource for craniofacial bone regeneration due to their high abundance and easy accessibility, significant osteogenic potential, versatile applications, and potential for personalized medicine, which underscore their importance in this field. This article reviews the current progress of preclinical studies that describe the careful selection of specific ADSC subpopulations, key signaling pathways involved, and usage of various strategies to enhance the osteogenic potential of ADSCs. Additionally, clinical case reports regarding the application of ADSCs in the repair of calvarial defects, cranio-maxillofacial defects, and alveolar bone defects are also discussed.