Dexamethasone induces trabecular meshwork cell myofibroblast transdifferentiation through ARHGEF26.

Glucocorticoid use may cause elevated intraocular pressure, leading to the development of glucocorticoid-induced glaucoma (GIG). However, the mechanism of GIG development remains incompletely understood. In this study, we subjected primary human trabecular meshwork cells (TMCs) and mice to dexamethasone treatment to mimic glucocorticoid exposure. The myofibroblast transdifferentiation of TMCs was observed in cellular and mouse models, as well as in human trabecular mesh specimens. This was demonstrated by the cytoskeletal reorganization, alterations in cell morphology, heightened transdifferentiation markers, increased extracellular matrix deposition, and cellular dysfunction. Knockdown of Rho guanine nucleotide exchange factor 26 (ARHGEF26) expression ameliorated dexamethasone-induced changes in cell morphology and upregulation of myofibroblast markers, reversed dysfunction and extracellular matrix deposition in TMCs, and prevented the development of dexamethasone-induced intraocular hypertension. And, this process may be related to the TGF-ß pathway. In conclusion, glucocorticoids induced the myofibroblast transdifferentiation in TMCs, which played a crucial role in the pathogenesis of GIG. Inhibition of ARHGEF26 expression protected TMCs by reversing myofibroblast transdifferentiation. This study demonstrated the potential of reversing the myofibroblast transdifferentiation of TMCs as a new target for treating GIG.

Arf1 promotes porcine intestinal epithelial cell proliferation via the mTORC1 signaling pathway.

The promotion of gut health, a pervasive problem in modern animal husbandry, positively affects organismal health, productivity, and economics. Porcine intestinal epithelial cells (IPEC-J2) continuously proliferate to maintain intestinal homeostasis, including barrier, immune, and absorptive functions. Gut homeostasis is fundamental to organismal health. ADP-ribosylation factor 1 (Arf1), a small GTPase, plays a crucial role in coordinating mTORC1 in response to nutrients, especially amino acid availability in the gut. mTORC1 is the central hub of proliferation. Thus, it seems likely that Arf1 promotes IPEC-J2 cell proliferation. However, the exact role of Arf1 in the porcine gut remains unclear. Therefore, we evaluated the functional role and possible mechanisms of Arf1 in the porcine intestine through Arf1 overexpression and knockdown in IPEC-J2 cells. Arf1 overexpression and knockdown significantly enhanced and inhibited, respectively, IPEC-J2 cell viability, and PCNA expression varied with Arf1 expression. Moreover, the proportion of Ki67-positive cells was significantly greater in the Arf1-overexpressing group than in the control group. These results suggest that Arf1 improves IPEC-J2 cell proliferation. The underlying mechanism was explored by Western blotting. Arf1 overexpression and knockdown significantly enhanced and suppressed, respectively, the levels of p-S6K1 and p-RPS6, which are key downstream targets of the mTORC1 signaling pathway. Collectively, our findings reveal the role of the Arf1-mTORC1 axis in IPEC-J2 cell proliferation and its potential function in regulating intestinal homeostasis and health.

Redistribution and fusion of protein-lipid assemblies within the egg yolk sphere under slight non-destructive deformation causing a change in thermal gel properties.

Egg yolk production processed after separating egg white is a common method to shorten cycle, but its taste quality will change even the vitelline membrane is intact. This might be related to the slight non-destructive deformation causing redistribution and fusion of protein-lipid assemblies within the egg yolk spheres. We investigated the mechanism of the change in thermal gel properties under slight deformation. The results of microscopic structural morphology revealed that the whole boiled egg yolk (WEY) underwent a transition in protein-lipid assembly morphology within yolk spheres, which changed from local aggregation to disordered fusion in shaken boiled egg yolks (SEYs). The spectroscopic and physicochemical properties analysis demonstrated that the redistribution of protein-lipid assemblies gave rise to marked changes in water migration, texture properties, molecular interactions, and oral sensation simulation of egg yolk thermal gels. This is benefit to guide the regulation of the taste quality egg yolk products in industry.

A preliminary investigation into the impact of soft tissue augmentation-based periodontal phenotype modification therapy for patients exhibiting class III decompensation.

BACKGROUND: Patients with skeletal angle Class III malocclusion usually have inadequate hard and soft tissue volume at the mandibular anterior teeth. The labial proclination at the teeth may lead to gingival recession. The purpose of this study was to explore whether periodontal phenotype modification therapy with soft tissue augmentation (PhMT-s) can prevent gingival recession in these patients. METHODS: Four patients with skeletal Class III malocclusion and a thin periodontal phenotype underwent surgical-orthodontic treatment. Prior to tooth movement, they underwent a minimally invasive vestibular incision with subperiosteal tunnel access combined with autogenous connective tissue grafts for periodontal phenotype modification with soft tissue augmentation (PhMT-s). The labial gingival thickness of the anterior mandibular teeth was measured at three distinct levels: at the cementoenamel junction (GT0), 3 mm apical to the CEJ (GT3), and 6 mm apical to the CEJ (GT6). These measurements were taken at baseline, three months following PhMT-s, and after tooth decompensation. Additionally, a biopsy sample was obtained from the PhMT-s site of one patient. All sections were subsequently stained using hematoxylin and eosin, Masson trichrome, Sirius Red, and immunohistochemistry. RESULTS: The thickness of the labial gingiva was increased about 0.42 to 2.00 mm after PhMT-s. At the end of pre-orthognathic surgical orthodontic treatment, the thickness of the labial gingiva was increased about - 0.14 to 1.32 mm compared to the baseline and no gingival recession occurred after the pre-orthognathic surgical orthodontic treatment. The histologic results demonstrated that the grafts obtained from the PhMT-s site exhibited increased deposition of collagen fibers. Moreover, the proportion of type III collagen increased and the grafts displayed significantly reduced positive expression of CD31 and OCN. CONCLUSIONS: PhMT-s increased the thickness of the soft tissue, stabilizing the gingival margin for teeth exhibiting a thin periodontal phenotype and undergoing labial movement. This is attributed to the increased deposition of collagen fibers.

Suppression of CDK1/Drp1-mediated mitochondrial fission attenuates dexamethasone-induced extracellular matrix deposition in the trabecular meshwork.

AIMS: Deposition of extracellular matrix (ECM) in the trabecular meshwork (TM), as induced by dexamethasone (DEX), is believed to play an important role in the onset of glucocorticoid-induced glaucoma (GIG). Abnormal ECM deposition is a consequence of mitochondrial dysfunction. We aimed to clarify how mitochondrial dysfunction leads to ECM deposition within the TM and to support the development of novel therapeutic strategies. RESULTS: In primary human TM cells (pHTMCs) and a dexamethasone acetate-induced murine model of GIG, glucocorticoid administration stimulated both mitochondrial fission and ECM deposition. Excessive mitochondrial fission leads to dysfunction and the overexpression of ECM proteins in pHTMCs. Notably, when pHTMCs were treated with the Drp1 inhibitor Mdivi-1 or with Drp1 siRNA, we observed a marked reduction in DEX-induced mitochondrial damage and ECM proteins in vitro. Furthermore, in C57BL/6J mice, treatment with Mdivi-1 mitigated mitochondrial damage and blocked ECM deposition within the TM. We then employed Ro3306 to inhibit the CDK1-mediated phosphorylation of Drp1 at Ser 616, which restored mitochondrial function and diminished DEX-induced ECM protein expression in pHTMCs. INNOVATION: This study illuminates the pathogenic mechanism linking mitochondrial dysfunction to ECM deposition in GIG. Our innovative approach revealed that DEX stimulates mitochondrial fission via CDK1-mediated p-Drp1s616 overexpression, which drives ECM accumulation. It offered a novel therapeutic strategy for reducing ECM protein expression by inhibiting excessive mitochondrial fission and restoring mitochondrial function. CONCLUSION: By targeting the CDK1/Drp1-driven mitochondrial fission process, we can counteract DEX-induced ECM deposition in the TM both in vivo and in vitro.

Approaching crystal's limit of thermoelectrics by nano-sintering-aid at grain boundaries.

Grain boundary plays a vital role in thermoelectric transports, leading to distinct properties between single crystals and polycrystals. Manipulating the grain boundary to realize good thermoelectric properties in polycrystals similar as those of single crystals is a long-standing task, but it is quite challenging. Herein, we develop a liquid-phase sintering strategy to successfully introduce Mg2Cu nano-sintering-aid into the grain boundaries of Mg3(Bi, Sb)2-based materials. The nano-aid helps to enlarge the average grain size to 23.7 µm and effectively scatter phonons, leading to excellent electrical transports similar as those of single crystals and ultralow lattice thermal conductivity as well as exceptional thermoelectric figure of merit (1.5 at 500 K) and conversion efficiency (7.4% under temperature difference of 207 K). This work provides a simple but effective strategy for the fabrication of high-performance polycrystals for large-scale applications.

Novel genotypes and phenotypes in Snijders Blok-Campeau syndrome caused by CHD3 mutations.

Background: Snijders Blok-Campeau syndrome (SNIBCPS) is a rare genetic disorder characterized by facial abnormalities, hypotonia, macrocephaly, and global developmental delay (GDD) caused by mutations in CHD3 gene. There is limited information on SNIBCPS and few studies on its pathogenic gene CHD3. Methods: We utilized whole-exome sequencing, in vitro minigene splicing assay analysis, and construction of protein models to validate the suspected pathogenic mutation. In addition, the PubMed database was searched using the keywords "Snijders Blok-Campeau syndrome," "CHD3," or "SNIBCPS" to summarize the gene mutations and clinical phenotypic characteristics of children with SNIBCPS. Results: We identified a non-frameshift variant c.3592_c.3606delGCCAAGAGAAAGATG, a splice site variant c.1708-1G>T, and two missense variants, c. 2954G>C (p.Arg985Pro) and c.3371C>T (p.A1124V), in CHD3 variants with SNIBCPS. Importantly, the c.3592_c.3606delGCCAAGAGAAAGATG, c.1708-1G>T, and c.3371C > T (p.A1124V) loci were not reported, and the children in this study also had phenotypic features of unibrow, transverse palmar creases, tracheal bronchus, and hypomelanosis of Ito (HI). The c.1708-1G>T classical splicing mutation leads to abnormal shearing of mRNA, forming a truncated protein that ultimately affects gene function. Conclusion: Our findings have expanded the spectrum of genetic variants and clinical features in children with SNIBCPS. Splicing analysis of CHD3 is an important method to understand the pathogenesis of spliced cells.

Clinical and pathological characteristics of OPDM4 patients in advanced disease.

INTRODUCTION/AIMS: Oculopharyngodistal myopathy type 4 (OPDM4) arises from a CGG repeat expansion in the 5' UTR of the RILPL1 gene. Reported cases of OPDM4 have been limited. The aim of this study was to investigate the clinical and myopathological characteristics of OPDM4 patients with advanced disease. METHODS: We assessed a total of 8 affected and 12 unaffected individuals in an OPDM4 family with autosomal dominant inheritance. Muscle biopsy tissue from the proband underwent histological, enzyme histochemical, and immunohistochemical stains, and electron microscopy analysis. Whole exome sequencing and repeat primer PCR (RP-PCR) were conducted to investigate underlying variants. RESULTS: OPDM4 patients displayed a progressive disease course. Most experienced lower limb weakness and diminished walking ability in their 20s and 30s, followed by ptosis, ophthalmoplegia, swallowing difficulties, and dysarthria in their 30s to 50s, By their 50s to 70s, they became non-ambulatory. Muscle magnetic resonance imaging (MRI) of the proband in advanced disease revealed severe fatty infiltration of pelvic girdle and lower limb muscles. Biopsied muscle tissue exhibited advanced changes typified by adipose connective tissue replacement and the presence of multiple eosinophilic and p62-positive intranuclear inclusions. Immunopositivity for the intranuclear inclusions was observed with anti-glycine antibody and laboratory-made polyA-R1 antibody. RP-PCR unveiled an abnormal CGG repeat expansion in the 5' UTR of the RILPL1 gene. DISCUSSION: The clinical and radiological features in this family broaden the phenotypic spectrum of OPDM4. The presence of intranuclear inclusions in the proliferative adipose connective tissues of muscle biopsy specimens holds diagnostic significance for OPDM4 in advanced disease.

A viral effector blocks the turnover of a plant NLR receptor to trigger a robust immune response.

Plant intracellular nucleotide-binding and leucine-rich repeat immune receptors (NLRs) play a key role in activating a strong pathogen defense response. Plant NLR proteins are tightly regulated and accumulate at very low levels in the absence of pathogen effectors. However, little is known about how this low level of NLR proteins is able to induce robust immune responses upon recognition of pathogen effectors. Here, we report that, in the absence of effector, the inactive form of the tomato NLR Sw-5b is targeted for ubiquitination by the E3 ligase SBP1. Interaction of SBP1 with Sw-5b via only its N-terminal domain leads to slow turnover. In contrast, in its auto-active state, Sw-5b is rapidly turned over as SBP1 is upregulated and interacts with both its N-terminal and NB-LRR domains. During infection with the tomato spotted wilt virus, the viral effector NSm interacts with Sw-5b and disrupts the interaction of Sw-5b with SBP1, thereby stabilizing the active Sw-5b and allowing it to induce a robust immune response.

ROS induced pyroptosis in inflammatory disease and cancer.

Pyroptosis, a form of caspase-1-dependent cell death, also known as inflammation-dependent death, plays a crucial role in diseases such as stroke, heart disease, or tumors. Since its elucidation, pyroptosis has attracted widespread attention from various sectors. Reactive oxygen species (ROS) can regulate numerous cellular signaling pathways. Through further research on ROS and pyroptosis, the level of ROS has been revealed to be pivotal for the occurrence of pyroptosis, establishing a close relationship between the two. This review primarily focuses on the molecular mechanisms of ROS and pyroptosis in tumors and inflammatory diseases, exploring key proteins that may serve as drug targets linking ROS and pyroptosis and emerging fields targeting pyroptosis. Additionally, the potential future development of compounds and proteins that influence ROS-regulated cell pyroptosis is anticipated, aiming to provide insights for the development of anti-tumor and anti-inflammatory drugs.

Synaptotagmin-1 undergoes phase separation to regulate its calcium-sensitive oligomerization.

Synaptotagmin-1 (Syt1) is a calcium sensor that regulates synaptic vesicle fusion in synchronous neurotransmitter release. Syt1 interacts with negatively charged lipids and the SNARE complex to control the fusion event. However, it remains incompletely understood how Syt1 mediates Ca2+-trigged synaptic vesicle fusion. Here, we discovered that Syt1 undergoes liquid-liquid phase separation (LLPS) to form condensates both in vitro and in living cells. Syt1 condensates play a role in vesicle attachment to the PM and efficiently recruit SNAREs and complexin, which may facilitate the downstream synaptic vesicle fusion. We observed that Syt1 condensates undergo a liquid-to-gel-like phase transition, reflecting the formation of Syt1 oligomers. The phase transition can be blocked or reversed by Ca2+, confirming the essential role of Ca2+ in Syt1 oligomer disassembly. Finally, we showed that the Syt1 mutations causing Syt1-associated neurodevelopmental disorder impair the Ca2+-driven phase transition. These findings reveal that Syt1 undergoes LLPS and a Ca2+-sensitive phase transition, providing new insights into Syt1-mediated vesicle fusion.

A fibronectin gradient remodels mixed-phase mesoderm.

Physical processes ultimately shape tissue during development. Two emerging proposals are that cells migrate toward stiffer tissue (durotaxis) and that the extent of cell rearrangements reflects tissue phase, but it is unclear whether and how these concepts are related. Here, we identify fibronectin-dependent tissue stiffness as a control variable that underlies and unifies these phenomena in vivo. In murine limb bud mesoderm, cells are either caged, move directionally, or intercalate as a function of their location along a stiffness gradient. A modified Landau phase equation that incorporates tissue stiffness accurately predicts cell diffusivity upon loss or gain of fibronectin. Fibronectin is regulated by WNT5A-YAP feedback that controls cell movements, tissue shape, and skeletal pattern. The results identify a key determinant of phase transition and show how fibronectin-dependent directional cell movement emerges in a mixed-phase environment in vivo.

Protective Effect of Nicotinamide Riboside on Glucocorticoid-Induced Glaucoma: Mitigating Mitochondrial Damage and Extracellular Matrix Deposition.

Purpose: Glucocorticoid-induced glaucoma (GIG) is a prevalent complication associated with glucocorticoids (GCs), resulting in irreversible blindness. GIG is characterized by the abnormal deposition of extracellular matrix (ECM) in the trabecular meshwork (TM), elevation of intraocular pressure (IOP), and loss of retinal ganglion cells (RGCs). The objective of this study is to investigate the effects of nicotinamide riboside (NR) on TM in GIG. Methods: Primary human TM cells (pHTMs) and C57BL/6J mice responsive to GCs were utilized to establish in vitro and in vivo GIG models, respectively. The study assessed the expression of ECM-related proteins in TM and the functions of pHTMs to reflect the effects of NR. Mitochondrial morphology and function were also examined in the GIG cell model. GIG progression was monitored through IOP, RGCs, and mitochondrial morphology. Intracellular nicotinamide adenine dinucleotide (NAD+) levels of pHTMs were enzymatically assayed. Results: NR significantly prevented the expression of ECM-related proteins and alleviated dysfunction in pHTMs after dexamethasone treatment. Importantly, NR protected damaged ATP synthesis, preventing overexpression of mitochondrial reactive oxygen species (ROS), and also protect against decreased mitochondrial membrane potential induced by GCs in vitro. In the GIG mouse model, NR partially prevented the elevation of IOP and the loss of RGCs. Furthermore, NR effectively suppressed the excessive expression of ECM-associated proteins and mitigated mitochondrial damage in vivo. Conclusions: Based on the results, NR effectively enhances intracellular levels of NAD+, thereby mitigating abnormal ECM deposition and TM dysfunction in GIG by attenuating mitochondrial damage induced by GCs. Thus, NR has promising potential as a therapeutic candidate for GIG treatment.

Reply to "Matters arising: cost-effectiveness of first-line immunotherapy combinations with or without chemotherapy for advanced non-small cell lung cancer: a modelling approach".

In this article, we read with great attention the correspondence by Bullement et al., regarding our published study on cost-effectiveness of first-line immunotherapy combinations with or without chemotherapy for advanced non-small cell lung cancer. We referred to a few the most important comments from Bullement et al. in our opinion, including proportional hazard (PH) assumption, accelerated failure time (AFT) model, and health utility, and made some explanations.

Cerebral involvement in sitosterolemia.

BACKGROUND: Sitosterolemia, an autosomal recessive condition, is characterized by impaired metabolism of plant sterols. Clinical symptoms include skin xanthoma, premature atherosclerotic disease, arthritis, and unexplained hematological abnormalities. However, there is a dearth of studies on sitosterolemia-related brain damage. METHODS: This study focused on the family of two sitosterolemia patients who presented with severe hypercholesterolemia and xanthoma. Radiological examinations, biopsies, whole-exome sequencing (WES), and plant sterol tests were conducted. RESULTS: The index patient, a 66-year-old female, initially exhibited weakness in both lower limbs and later developed urinary and fecal incontinence. Neuroimaging showed that the falx of the brain had irregular fusiform thickening. Significant tissue edema was observed around the lesions in the bilateral frontal-parietal lobes. Pathological analysis of the biopsied brain lesion revealed extensive cholesterol crystal deposition and lymphocyte infiltration in the matrix. The index patient who experienced cerebral impairment and her sister both carried two compound heterozygous variants in ATP binding cassette transporter G5 (ABCG5). These included the nonsense variants NM_022436: c.751 C > T (p.Q251X) in exon 6 and NM_022436: c.1336 C > T (p.R446X) in exon 10. A notable increase in plant sterol levels was observed in the younger sister of the index patient. CONCLUSION: This study highlights a previously unreported neurological aspect of sitosterolemia. Imaging and pathology findings suggest that cholesterol crystals may be deposited in connective tissues such as the cerebral falx and pia mater through blood circulation.

Genome wide identification of novel DNA methylation driven prognostic markers in colorectal cancer.

Colorectal cancer (CRC) stands as a major contributor to cancer-related fatalities within China. There is an urgent need to identify accurate biomarkers for recurrence predicting in CRC. Reduced representation bisulfite sequencing was used to perform a comparative analysis of methylation profiles in tissue samples from 30 recurrence to 30 non-recurrence patients with CRC. Least absolute shrinkage and selection operator method was performed to select the differential methylation regions (DMRs) and built a DNA methylation classifier for predicting recurrence. Based on the identified top DMRs, a methylation classifier was built and consisted of eight hypermethylated DMRs in CRC. The DNA methylation classifier showed high accuracy for predicting recurrence with an area under the receiver operator characteristic curve of 0.825 (95% CI 0.680-0.970). The Kaplan-Meier survival analysis demonstrated that CRC patients with high methylation risk score, evaluated by the DNA methylation classifier, had poorer survival than low risk score (Hazard Ratio 4.349; 95% CI 1.783-10.61, P = 0.002). And only CRC patients with low methylation risk score could acquire benefit from adjuvant therapy. The DNA methylation classifier has been proved as crucial biomarkers for predicting recurrence and exhibited promising prognostic value after curative surgery in patients with CRC.

Cardiometabolic multimorbidity, peripheral biomarkers, and dementia in rural older adults: The MIND-China study.

INTRODUCTION: Evidence has emerged that cardiometabolic multimorbidity (CMM) is associated with dementia, but the underlying mechanisms are poorly understood. METHODS: This population-based study included 5704 older adults. Of these, data were available in 1439 persons for plasma amyloid-ß (Aß), total tau, and neurofilament light chain (NfL) and in 1809 persons for serum cytokines. We defined CMM following two common definitions used in previous studies. Data were analyzed using general linear, logistic, and mediation models. RESULTS: The presence of CMM was significantly associated with an increased likelihood of dementia, Alzheimer's disease (AD), and vascular dementia (VaD) (p < 0.05). CMM was significantly associated with increased plasma Aß40, Aß42, and NfL, whereas CMM that included visceral obesity was associated with increased serum cytokines. The mediation analysis suggested that plasma NfL significantly mediated the association of CMM with AD. DISCUSSION: CMM is associated with dementia, AD, and VaD in older adults. The neurodegenerative pathway is involved in the association of CMM with AD. HIGHLIGHTS: The presence of CMM was associated with increased likelihoods of dementia, AD, and VaD in older adults. CMM was associated with increased AD-related plasma biomarkers and serum inflammatory cytokines. Neurodegenerative pathway was partly involved in the association of CMM with AD.

Dihydroquercetin improves the proliferation of porcine intestinal epithelial cells via the Wnt/ß-catenin pathway.

Dihydroquercetin (DHQ), also known as Taxifolin (TA), is a flavanonol with various biological activities, such as anticancer, anti-inflammatory, and antioxidative properties. It has been found to effectively increase the viability of porcine intestinal epithelial cells (IPEC-J2). However, the precise mechanism by which DHQ increases the proliferation of IPEC-J2 cells is not entirely understood. This study aimed to explore the potential pathways through which DHQ encourages the proliferation of IPEC-J2 cells. The findings indicated that DHQ significantly improved the protein expression of tight junction proteins (ZO-1, Occludin, and Claudin1) and a molecular biomarker of proliferation (PCNA) in IPEC-J2 cells. Furthermore, DHQ was found to increase the Wnt/ß-catenin pathway-associated ß-catenin, c-Myc, and cyclin D1 mRNA expression, and promote the protein expression of ß-catenin and TCF4. To confirm the involvement of the Wnt/ß-catenin signaling pathway in the DHQ-promoted proliferation of IPEC-J2 cells, the inhibitor LF3, which targets ß-catenin/TCF4 interaction, was used. It was found that LF3 inhibited the protein expressions upregulated by DHQ and blocked the promotion of cell proliferation. These results indicate that DHQ positively regulates IPEC-J2 cell proliferation through the Wnt/ß-catenin pathway, providing constructive insights into the role of DHQ in regulating intestine development.

Validation of an AI-Powered Automated X-ray Bone Age Analyzer in Chinese Children and Adolescents: A Comparison with the Tanner-Whitehouse 3 Method.

INTRODUCTION: Automated bone age assessment (BAA) is of growing interest because of its accuracy and time efficiency in daily practice. In this study, we validated the clinical applicability of a commercially available artificial intelligence (AI)-powered X-ray bone age analyzer equipped with a deep learning-based automated BAA system and compared its performance with that of the Tanner-Whitehouse 3 (TW-3) method. METHODS: Radiographs prospectively collected from 30 centers across various regions in China, including 900 Chinese children and adolescents, were assessed independently by six doctors (three experts and three residents) and an AI analyzer for TW3 radius, ulna, and short bones (RUS) and TW3 carpal bone age. The experts' mean estimates were accepted as the gold standard. The performance of the AI analyzer was compared with that of each resident. RESULTS: For the estimation of TW3-RUS, the AI analyzer had a mean absolute error (MAE) of 0.48 ± 0.42. The percentage of patients with an absolute error of < 1.0 years was 86.78%. The MAE was significantly lower than that of rater 1 (0.54 ± 0.49, P = 0.0068); however, it was not significant for rater 2 (0.48 ± 0.48) or rater 3 (0.49 ± 0.46). For TW3 carpal, the AI analyzer had an MAE of 0.48 ± 0.65. The percentage of patients with an absolute error of < 1.0 years was 88.78%. The MAE was significantly lower than that of rater 2 (0.58 ± 0.67, P = 0.0018) and numerically lower for rater 1 (0.54 ± 0.64) and rater 3 (0.50 ± 0.53). These results were consistent for the subgroups according to sex, and differences between the age groups were observed. CONCLUSION: In this comprehensive validation study conducted in China, an AI-powered X-ray bone age analyzer showed accuracies that matched or exceeded those of doctor raters. This method may improve the efficiency of clinical routines by reducing reading time without compromising accuracy.

Assessing bone age, or how developed a child's skeleton is, is important in medical care, but the standard method can be time-consuming. Using AI to automatically assess bone age from X-ray images may improve efficiency without reducing accuracy. In this study, we evaluated how well an AI-powered X-ray bone age analyzer performed compared to the established Tanner­Whitehouse 3 (TW-3) method. X-ray images from 900 Chinese children and adolescents were collected from 30 centers. Six doctors (three experts, three residents) and the AI system independently assessed the TW-3 radius, ulna, and short bones (RUS) and TW-3 carpal bone age. The experts' assessments were considered the gold standard. The AI analyzer had an average error of 0.48 years for TW3-RUS bone age, with 87% of assessments within 1 year of the experts. For TW3 carpal bone age, the AI had an average error of 0.48 years, with 89% within 1 year. These results were similar to or better than those of the resident raters. These findings show the AI-powered analyzer can assess bone age as accurately as human raters. This technology may improve clinical efficiency by reducing the time required for bone age assessments without compromising accuracy.