Over the past two decades, genome-wide association study(GWAS) has identified numerous genetic variants and loci associated with heritable diseases. With the gradual maturation and saturation of GWAS methodologies, transcriptome-wide association study(TWAS) offers a novel perspective by linkinggenetic phenotypes to gene expression levels. By integrating TWAS with other multi-omics analyses, researchers can gain a deeper understanding of heritable diseases. This article provides an overview of recent groundbreaking and representative TWAS methods and tools, analyzes their strengths and limitations, and discusses future trends in TWAS development.

Background With China's socio-economic development, the dietary structure of Chinese residents has gradually shifted from a traditional Eastern pattern characterized by high carbohydrate intake to a relatively high-fat Western dietary model, alongside a growing burden of chronic diseases. However, dietary changes may vary across different occupational groups. Objective To analyze the long-term trends in dietary energy and three major macronutrient intake among various occupational groups aged 18-59 years in nine provinces of China from 1989 to 2018, providing a scientific basis for developing occupation-specific dietary intervention strategies. Methods Based on 11 waves of data (1989–2018) from the China Health and Nutrition Survey (CHNS), 57458 employed individuals aged 18-59 years were selected as observation subjects after applying inclusion and exclusion criteria. Joinpoint regression was used to analyze temporal trends by calculating the annual percentage change (APC) and average annual percentage change (AAPC) with 95% confidence intervals. The analysis covered the energy supply ratio from the three major macronutrients and the proportion of the participants within the acceptable macronutrient distribution ranges (AMDR) for the total occupational population and specific occupational group. Results From 1989 to 2018, the dietary structure of the occupational population in the nine provinces gradually Westernized. The carbohydrate energy supply ratio showed a decreasing trend (AAPC=−0.77%, 95%CI: −1.00%, −0.55%, P<0.05), while the fat energy supply ratio increased (AAPC=1.42%, 95%CI: 1.07%, 1.77%, P<0.05). The protein energy supply ratio remained largely unchanged (AAPC=−0.19%, 95%CI: −0.08%, 0.46%, P>0.05), and the total energy intake declined (AAPC=−0.62%, 95%CI: −0.94%, −0.30%, P<0.05). Among the occupational groups studied, white-collar workers were the first to show characteristics of dietary Westernization. Using the AMDR as the criterion, their average fat energy supply ratio first exceeded the AMDR upper limit (30%) in 1993, and their average carbohydrate energy supply ratio first fell below the AMDR lower limit (50%) in 2006, both time points being earlier than other occupational groups. Agricultural workers lagged in this transition (their average fat energy supply ratio first reached ≥30% in 2011), but their rate of increase in the fat energy supply ratio was the fastest among all occupational groups (AAPC=1.59%, 95%CI: 0.90%, 2.30%, P<0.05; P for trend comparison between groups<0.05). The other three occupational groups (blue-collar workers, service workers, and others) generally fell between these two extremes. Taking the fat energy supply ratio as an example, their AAPCs of increase were 1.02% (95%CI: 0.73%, 1.32%, P<0.05) for blue-collar workers, 0.85% (95%CI: 0.61%, 1.09%, P<0.05) for service workers, and 0.88% (95%CI: 0.58%, 1.17%, P<0.05) for others. Conclusion From 1989 to 2018, the macronutrient structure of the occupational population aged 18-59 years in nine China provinces is gradually Westernized. The energy supply ratios of carbohydrates and proteins primarily face issues of potential inadequacy, while the fat energy supply ratio is excessively high. Furthermore, the patterns of change vary among different occupational groups. It is recommended to propose personalized dietary advice tailored to specific occupations.

Background With China's socioeconomic development, significant lifestyle changes have occurred among occupational groups, leading to alterations in cardiovascular metabolic risk factors. However, few studies have examined the secular trends of these risk factors in China's working population. Objective To analyze the trends in cardiovascular metabolic risk factors among the occupational population in nine provinces of China from 2009 to 2018, and to explore the associations between different occupational types and these risk factors, along with their clustering patterns, thereby providing evidence for targeted interventions. Methods This study utilized data from the China Health and Nutrition Survey (CHNS) in 2009, 2015, and 2018. The dataset covered 13274 employed individuals aged 18-59 years. Only participants with complete blood test results and physical measurement data were included in the final analysis. The average annual percentage change (AAPC) in the positive rates of risk factors was calculated using Joinpoint regression to analyze temporal trends. Multinomial logistic regression and binary logistic regression models were employed to examine the cross-sectional associations between occupational types (categorized as white-collar workers, agricultural workers, blue-collar workers, service workers, and others) and nine cardiovascular metabolic risk factors and their clustering (defined as having ≥2 risk factors) in 2018. Results A total of 8451 participants were included. From 2009 to 2018, significant increasing trends (AAPC>0, P<0.05) were observed for overweight, obesity, central obesity, borderline elevated triglycerides (TG), borderline elevated to elevated total cholesterol (TC), borderline elevated low-density lipoprotein cholesterol (LDL-C), elevated blood pressure and hypertension, diabetes. The most rapid increases were found for obesity (AAPC=6.07%, 95%CI: 3.42%, 8.88%), hypertension (AAPC=4.10%, 95%CI: 0.62%, 7.77%), and central obesity (AAPC=3.27%, 95%CI: 1.24%, 5.36%). The clustering rate of risk factors increased from 62.3% in 2009 to 73.2% in 2018 (AAPC=1.87%, 95%CI: 1.02%, 2.73%). The cross-sectional analysis in 2018, after adjusting for confounders, showed that compared with white-collar workers, blue-collar workers had a significantly lower risk of overweight (OR=0.67, 95%CI: 0.48, 0.95), central obesity (OR=0.65, 95%CI: 0.45, 0.92), and borderline high TG (OR=0.54, 95%CI: 0.35, 0.82). In contrast, agricultural workers had a higher risk of hypertension (OR=1.76, 95%CI: 1.14, 2.72). Conclusion Between 2009 and 2015, the burden of most cardiometabolic risk factors increases significantly among the Chinese occupational population, with the rate of increase slowing by 2018. Risks vary across occupational types, among which blue- collar workers report lower target outcomes. Targeted interventions focusing on the rapidly increasing risk factors and high-risk occupational groups are recommended.

Background The global prevalence of obesity is on the rise and is closely associated with various chronic non-communicable diseases such as cardiovascular diseases and diabetes. There is a relative lack of long-term dynamic studies on compound obesity among occupational populations. Objective To explore the changing trends of compound obesity among different occupational groups aged 18–59 years in nine provinces (autonomous regions, municipalities) of China from 1993 to 2018, and to provide a scientific basis for formulating targeted weight management strategies for occupational populations. Methods A total of 34519 employed adults aged 18–59 years from nine waves of the China Health and Nutrition Survey in1993, 1997, 2000, 2004, 2006, 2009, 2011, 2015, and 2018 were included. Obesity types were determined according to the Chinese Adult Weight Management Guidelines. The Joinpoint regression model was used to calculate the average annual percentage change (AAPC) and annual percentage change (APC) of compound obesity rates. Results From 1993 to 2018, the age-standardized compound obesity rate among the occupational population aged 18–59 years showed an upward trend (AAPC=6.24%, 95%CI: 5.09%, 7.41%, P<0.05). The AAPCs (95%CI) for age-standardized compound obesity rates among agricultural workers, blue-collar workers, other occupational groups, service workers, and white-collar workers were 9.55% (7.51%, 11.64%), 6.18% (4.70%, 7.69%), 5.53% (2.27%, 8.90%), 4.07% (2.40%, 5.77%), and 3.89% (2.16%, 5.65%), respectively, with statistically significant differences (P<0.05). Among males, the AAPCs (95%CI) for age-standardized compound obesity rates among agricultural workers, blue-collar workers, other occupational groups, service workers, and white-collar workers were 11.52% (7.71%, 15.47%), 7.28% (6.18%, 8.40%), 5.92% (2.28%, 9.69%), 5.56% (2.11%, 9.12%), and 4.22% (2.33%, 6.15%), respectively, with statistically significant differences (P<0.05). Among females, the AAPCs (95%CI) for age-standardized compound obesity rates among agricultural workers, blue-collar workers, and white-collar workers were 7.45% (6.22%, 8.69%), 3.72% (0.84%, 6.67%), and 2.41% (0.17%, 4.70%), respectively, with statistically significant differences (P<0.05). A turning point was observed in the compound obesity rate among female white-collar workers in 2006, with an APC (95%CI) of 9.69% (5.24%, 14.33%) from 2006 to 2008, showing a statistically significant difference (P<0.05), while no significant trend was found from 1993 to 2006 (P>0.05). No significant trends were observed in the age-standardized compound obesity rates among females in other occupational groups and service workers (P>0.05). Conclusion The compound obesity rate among China's occupational population is increasing rapidly, with the growth rate among agricultural workers being particularly prominent. In 2018, male white-collar workers and female agricultural workers exhibit relatively high compound obesity rates, warranting focused attention. Although the overall growth rate among service workers is slower, the expanding workforce in this sector indicates that obesity remains a serious issue. Targeted occupational health and weight management interventions are needed in the future.

Background With rising obesity rates and earlier hypertension onset among occupational populations, there is an urgent need to elucidate the long-term cardiovascular impacts of dynamic body weight patterns. Current evidence lacks trajectory modeling studies examining occupation-specific prevention strategies. Objective To investigate the association between long-term body mass index (BMI) trajectories and incident hypertension risk in Chinese working adults, and to examine occupation-specific heterogeneity in this relationship. Methods A dynamic sub-cohort of 4 413 occupational participants was constructed from ten survey waves (1991–2018) of the China Health and Nutrition Survey (CHNS). Eligible individuals had valid key BMI records at three or more independent follow-ups before the outcome event; the individual baseline was set as the year of their first participation in the survey. Group-based trajectory modeling (GBTM) was used to identify BMI change patterns. Cox proportional hazards regression was used to calculate hazard ratios (HRs) and 95% confidence interval (CI) for hypertension incidence across trajectory groups, with stratified analysis by occupational categories. Results Among 4413 occupational participants, 1441 incident hypertension cases were reported during the follow-up window. Three long-term BMI trajectories were identified: low-stable, moderate-slowly rising, and high-rising. In Model 3 with all selected confounders adjusted, compared with the low-stable group, the moderate-slowly rising group showed a significantly higher risk of incident hypertension (HR=1.28, 95%CI: 1.12, 1.45; P < 0.001), as did the high-increasing group (HR=1.80, 95%CI: 1.45, 2.23; P < 0.001). The stratified analyses revealed occupational differences in the association. Among agricultural workers, the moderate-slowly rising group (HR=1.35, 95%CI: 1.15, 1.57) and the high-rising group (HR=2.00, 95%CI: 1.50, 2.66) both exhibited significantly increased risks of hypertension (P<0.001). Conversely, among white-collar workers, an increased risk of hypertension was observed only in the high-rising group (HR=1.97, 95%CI: 1.23, 3.17; P<0.05). Conclusion Rapid BMI escalation constitutes a significant risk factor for incident hypertension in occupational populations. Targeted long-term weight monitoring and tailored interventions are recommended for high-risk occupations.

Objective Based on the Ancient and Modern Medical Case Cloud Platform V2.3.7,analyze the medication pattern and mechanism of action of Chinese medicines commonly used in famous medical cases for the treatment of Alzheimer's disease(AD).Methods The core Chinese medicines for AD were screened according to the inclusion and exclusion criteria by searching the famous Chinese medicine cases in the platform,then established the disease-core Chinese medicines-active ingredients-common targets network.The protein-protein interaction network(PPI)was established through the common targets.Gene oncology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analyses were performed by David platform.Molecular docking and dynamics simulations were employed to evaluate the binding affinity and stability between key targets and active ingredients.Results Data mining was performed on all the famous medical cases from the time of database construction to October 2023,and the results were summarized as follows.The high-frequency regulating Qi medications and tonifying Qi medications were Citri Reticulatae Pericarpium and Aurantii Fructus Immaturus;Panax ginseng,Ziziphi Jujubae Fructus,Codonopsis pilosula,Astragali Radix,Atractylodis Macrocephalae Rhizoma,Dioscoreae Rhizoma,and Glycyrrhizae Radix et Rhizoma.The core herbs contained 778 active ingredients and 377 targets;1986 disease targets;79 common targets were obtained after intersection with AD targets,and 7 core targets were identified through PPI network topology analysis,including TNF,AKT1,TP53,PPARG,etc.GO and KEGG pathway enrichment analyses confirmed that the targets of the active ingredients of the core herbs involved 138 pathways,and the core herbs could regulate chemical carcinogenesis-receptor activation、serotonergic synapse、chemical carcinogenesis-reactive oxygen species pathways to treat AD.Molecular docking and molecular dynamics simulation results showed good binding ability and stability between the key targets and the core components.Conclusion Through data mining to analyze the core herbs for the treatment of AD,the present investigation showing the pharmacological mechanism of 12-O-Nicotinoylisolineolone and Odoratin in the treatment of Alzheimer's disease at the molecular level,lay a certain theoretical foundation of 12-O-Nicotinoylisolineolone and Odoratin in the future.

Objective To investigate the role of membrane-associated tyrosine/threonine-protein ki-nase 1(PKMYT1)in glucocorticoid(GC)-induced osteoblast(OB)apoptosis,providing a theoretical basis and potential therapeutic targets for early-stage steroid-induced avascular necrosis of the femoral head(SANFH).Methods(1)Mouse calvarial osteoblastic cells(MC3T3-E1)were selected for the study.The control group was cultured in standard medium,while the experimental group was subject-ed to osteogenic induction culture,with osteogenic capacity verified by alkaline phosphatase(ALP)and Alizarin Red S(ARS)staining.Then,mouse osteoblasts(mOB)were treated with different con-centrations of GC.After that,apoptosis was detected by using Annexin V-FITC/PI double staining as-say,while cell proliferation was assessed by using Cell Counting Kit-8(CCK8).Moreover,the expres-sions of anti-apoptotic protein B-cell lymphoma/leukemia-2(BCL-2),pro-apoptotic proteins cleaved caspase-3andcleavedcaspase-9(cleavedcaspase 3/9)weredetectedbyusing Westernblotting(WB).Meanwhile,proteomic analysis was employed to identify molecules potentially regulating GC-in-duced apoptosis in mOBs.What's more,quantitative real-time PCR(qPCR)and WB were used to further analyze PKMYT1 expression.(2)mOBs were treated with PKMYT1 inhibitor GSK-1520489A of different concentrations to screen the optimal one,and all subjects were then further divided into a control,a GC,a GSK-1520489A,and a GC+GSK-1520489A group.Later,the expression of PK-MYT1 and apoptosis-related proteins BCL-2 and cleaved caspase 3/9 of all groups were detected us-ing WB,and cell viability and cytotoxicity were evaluated by CCK8 assay,with cell proliferation by using 5-ethynyl-2'-deoxyuridine(EDU)assay and apoptosis by cell live/dead staining and Annexin V-FITC/PI double staining.(3)mOBs were infected with PKMYT1 overexpression lentiviral vectors,and its efficiency was verified by using immunofluorescence,qPCR,and WB.After successful overexpres-sion of PKMYT1,all cells were divided into the control,GC,PKMYT1 overexpression(OE),and OE+GC groups,whose cell proliferation was detected by EDU assay,and apoptosis was assessed by Annexin V-FITC/PI double staining and cell live/dead staining.(4)To verify the changes in PKMYT1 expression in human osteoblasts(hOB),hOBs extracted from human femoral heads of healthy individu-als were chosen into the control group,while those from patients with hormone-induced avascular ne-crosis of the femoral head(hSANFH)were selected into the hSANFH group.Then,PKMYT1 expres-sion in both groups was detected by using qPCR and WB.Results(1)After inducing the differentia-tion of mouse calvarial osteoblastic cells(MC3T3-E1)into mature osteoblasts,under the action of GC,compared with the control group,with the increase of GC concentration,the experimental group showed increased mOB apoptosis(P<0.01)and expression of cleaved caspase 3/9(P<0.01),but de-creased cell viability(P<0.01)and expressionof apoptosis-relatedprotein BCL-2(P<0.01).More-over,according to the proteomic sequencing,significant decrease was observed in the PKMYT1 expres-sion in mature mOBs treated with GC.(2)As to treatment of mOBs with different concentrations of PKMYT1 inhibitor GSK-1520489A,with the increase of concentration,cell viability decreased and cy-totoxicity increased(P<0.001).Moreover,compared with the control group,mOBs proliferation de-creased(P<0.001)and apoptosis increased(P<0.001)in the GSK-1520489A group.Meanwhile,com-pared with the GC group,mOB proliferation decreased(P<0.05)and apoptosis increased significantly(P<0.01)in the GC+GSK-1520489A group.(3)After overexpression of PKMYT1,in comparison with the control group,mOB proliferation increased(P<0.001)but apoptosis did not increase significantly(P>0.05)in the OE group.Moreover,compared with the GC group,mOB proliferation increased(P<0.001)but apoptosis decreased(P<0.001)significantly in the OE+GC group.(4)In hOBs extracted from human femoral head tissues,qPCR and WB results showed that PKMYT1 expression of the hSANFH group was significantly lower than the control group(P<0.001).Conclusion Down regulation of PKMYT1 expression promotes GC-induced apoptosis of mOBs.Conversely,over expression of PK-MYT1 inhibits GC-induced apoptosis of mOBs.Therefore,PKMYT1 may serve as a potential target for the early treatment of SANFH.

BACKGROUND:In most species,a bone defect that is longer than 1.5 or 2 times its diameter can be considered a critical bone defect,and when the bone defect volume reaches the critical value,it cannot heal on its own.Currently,there is no uniform standard for the size of critical-sized defects in the osteoporotic femoral condyle of rabbits.OBJECTIVE:To establish a rabbit model with different sizes of bone defects in the osteoporotic femoral condyle and to determine the critical-sized defects of osteoporotic femoral condyle in rabbits.METHODS:Thirty-six 3-month-old female New Zealand white rabbits were randomly divided into ovariectomy group(n=30)and sham operation group(n=6).Rabbits in the ovariectomy group underwent bilateral ovariectomy to establish an osteoporosis model,and then femoral condyle bone defect models of different diameters(diameters were 4,5,6,and 7 mm,and depths were 8 mm)were further established;rabbits in the sham operation group did not undergo ovariectomy.At 8 and 12 weeks after modeling,3 rats were randomly selected from each group for CT scanning and three-dimensional reconstruction to evaluate the healing of bone defects.Afterwards,samples were taken for gross observation and hematoxylin-eosin staining to observe the growth of new bone in the femoral condyle bone defect area.RESULTS AND CONCLUSION:(1)All rabbits survived and moved well after modeling of osteoporosis and femoral condyle bone defect.(2)At 12 weeks after osteoporosis modeling,dual-energy X-ray absorptiometry results showed that the bone mineral density of lumbar vertebrae in ovariectomy group was significantly lower than that in sham operation group(P＜0.05).Hematoxylin-eosin staining showed that the bone trabeculae in the ovariectomy group became thinner and sparse.The proportion of bone tissue area in the ovariectomy group was significantly lower than that in the sham operation group(P=0.00).Micro-CT results showed that the bone tissue parameters of the femoral condyle in the ovariectomy group were significantly different from those in the sham operation group(P＜0.05),and the ovariectomy group showed obvious characteristics of osteoporosis.(3)CT showed that the bone defect in the 4 mm and 5 mm diameter groups was basically completely repaired at 12 weeks after surgery.There was more new bone tissue in the 6 mm diameter group,but the central part of the bone defect was not completely repaired.A small amount of new bone tissue grew in the 7 mm diameter group,and the bone defect was obvious.(4)Gross observation at 12 weeks after surgery showed that the femoral condyle bone defect in the 4 mm and 5 mm diameter groups was completely repaired.Obvious depression was seen in the bone defect area of the 6 mm and 7 mm diameter groups,and the bone defect was not completely repaired.(5)Histological observation at 12 weeks after surgery showed that the bone defect area of the 4 mm and 5 mm diameter groups was completely filled with new bone,and the trabecular structure was irregular;while there were new trabeculae in the periphery of the 6 mm and 7 mm diameter groups,and the bone defect in the central area was still obvious.(6)The results showed that during the 12-week experimental observation period of osteoporotic femoral condyle defects in rabbits,under the condition of the same defect depth of 8 mm,femoral condyle defects with a diameter ≥ 6 mm could not heal on their own,while femoral condyle defects with a diameter＜6 mm were completely repaired.A diameter of 6 mm and a depth of 8 mm can be used as the critical bone defect value of osteoporotic femoral condyle in rabbits.

BACKGROUND:In most species,a bone defect that is longer than 1.5 or 2 times its diameter can be considered a critical bone defect,and when the bone defect volume reaches the critical value,it cannot heal on its own.Currently,there is no uniform standard for the size of critical-sized defects in the osteoporotic femoral condyle of rabbits.OBJECTIVE:To establish a rabbit model with different sizes of bone defects in the osteoporotic femoral condyle and to determine the critical-sized defects of osteoporotic femoral condyle in rabbits.METHODS:Thirty-six 3-month-old female New Zealand white rabbits were randomly divided into ovariectomy group(n=30)and sham operation group(n=6).Rabbits in the ovariectomy group underwent bilateral ovariectomy to establish an osteoporosis model,and then femoral condyle bone defect models of different diameters(diameters were 4,5,6,and 7 mm,and depths were 8 mm)were further established;rabbits in the sham operation group did not undergo ovariectomy.At 8 and 12 weeks after modeling,3 rats were randomly selected from each group for CT scanning and three-dimensional reconstruction to evaluate the healing of bone defects.Afterwards,samples were taken for gross observation and hematoxylin-eosin staining to observe the growth of new bone in the femoral condyle bone defect area.RESULTS AND CONCLUSION:(1)All rabbits survived and moved well after modeling of osteoporosis and femoral condyle bone defect.(2)At 12 weeks after osteoporosis modeling,dual-energy X-ray absorptiometry results showed that the bone mineral density of lumbar vertebrae in ovariectomy group was significantly lower than that in sham operation group(P＜0.05).Hematoxylin-eosin staining showed that the bone trabeculae in the ovariectomy group became thinner and sparse.The proportion of bone tissue area in the ovariectomy group was significantly lower than that in the sham operation group(P=0.00).Micro-CT results showed that the bone tissue parameters of the femoral condyle in the ovariectomy group were significantly different from those in the sham operation group(P＜0.05),and the ovariectomy group showed obvious characteristics of osteoporosis.(3)CT showed that the bone defect in the 4 mm and 5 mm diameter groups was basically completely repaired at 12 weeks after surgery.There was more new bone tissue in the 6 mm diameter group,but the central part of the bone defect was not completely repaired.A small amount of new bone tissue grew in the 7 mm diameter group,and the bone defect was obvious.(4)Gross observation at 12 weeks after surgery showed that the femoral condyle bone defect in the 4 mm and 5 mm diameter groups was completely repaired.Obvious depression was seen in the bone defect area of the 6 mm and 7 mm diameter groups,and the bone defect was not completely repaired.(5)Histological observation at 12 weeks after surgery showed that the bone defect area of the 4 mm and 5 mm diameter groups was completely filled with new bone,and the trabecular structure was irregular;while there were new trabeculae in the periphery of the 6 mm and 7 mm diameter groups,and the bone defect in the central area was still obvious.(6)The results showed that during the 12-week experimental observation period of osteoporotic femoral condyle defects in rabbits,under the condition of the same defect depth of 8 mm,femoral condyle defects with a diameter ≥ 6 mm could not heal on their own,while femoral condyle defects with a diameter＜6 mm were completely repaired.A diameter of 6 mm and a depth of 8 mm can be used as the critical bone defect value of osteoporotic femoral condyle in rabbits.

Objective To investigate the role of membrane-associated tyrosine/threonine-protein ki-nase 1(PKMYT1)in glucocorticoid(GC)-induced osteoblast(OB)apoptosis,providing a theoretical basis and potential therapeutic targets for early-stage steroid-induced avascular necrosis of the femoral head(SANFH).Methods(1)Mouse calvarial osteoblastic cells(MC3T3-E1)were selected for the study.The control group was cultured in standard medium,while the experimental group was subject-ed to osteogenic induction culture,with osteogenic capacity verified by alkaline phosphatase(ALP)and Alizarin Red S(ARS)staining.Then,mouse osteoblasts(mOB)were treated with different con-centrations of GC.After that,apoptosis was detected by using Annexin V-FITC/PI double staining as-say,while cell proliferation was assessed by using Cell Counting Kit-8(CCK8).Moreover,the expres-sions of anti-apoptotic protein B-cell lymphoma/leukemia-2(BCL-2),pro-apoptotic proteins cleaved caspase-3andcleavedcaspase-9(cleavedcaspase 3/9)weredetectedbyusing Westernblotting(WB).Meanwhile,proteomic analysis was employed to identify molecules potentially regulating GC-in-duced apoptosis in mOBs.What's more,quantitative real-time PCR(qPCR)and WB were used to further analyze PKMYT1 expression.(2)mOBs were treated with PKMYT1 inhibitor GSK-1520489A of different concentrations to screen the optimal one,and all subjects were then further divided into a control,a GC,a GSK-1520489A,and a GC+GSK-1520489A group.Later,the expression of PK-MYT1 and apoptosis-related proteins BCL-2 and cleaved caspase 3/9 of all groups were detected us-ing WB,and cell viability and cytotoxicity were evaluated by CCK8 assay,with cell proliferation by using 5-ethynyl-2'-deoxyuridine(EDU)assay and apoptosis by cell live/dead staining and Annexin V-FITC/PI double staining.(3)mOBs were infected with PKMYT1 overexpression lentiviral vectors,and its efficiency was verified by using immunofluorescence,qPCR,and WB.After successful overexpres-sion of PKMYT1,all cells were divided into the control,GC,PKMYT1 overexpression(OE),and OE+GC groups,whose cell proliferation was detected by EDU assay,and apoptosis was assessed by Annexin V-FITC/PI double staining and cell live/dead staining.(4)To verify the changes in PKMYT1 expression in human osteoblasts(hOB),hOBs extracted from human femoral heads of healthy individu-als were chosen into the control group,while those from patients with hormone-induced avascular ne-crosis of the femoral head(hSANFH)were selected into the hSANFH group.Then,PKMYT1 expres-sion in both groups was detected by using qPCR and WB.Results(1)After inducing the differentia-tion of mouse calvarial osteoblastic cells(MC3T3-E1)into mature osteoblasts,under the action of GC,compared with the control group,with the increase of GC concentration,the experimental group showed increased mOB apoptosis(P<0.01)and expression of cleaved caspase 3/9(P<0.01),but de-creased cell viability(P<0.01)and expressionof apoptosis-relatedprotein BCL-2(P<0.01).More-over,according to the proteomic sequencing,significant decrease was observed in the PKMYT1 expres-sion in mature mOBs treated with GC.(2)As to treatment of mOBs with different concentrations of PKMYT1 inhibitor GSK-1520489A,with the increase of concentration,cell viability decreased and cy-totoxicity increased(P<0.001).Moreover,compared with the control group,mOBs proliferation de-creased(P<0.001)and apoptosis increased(P<0.001)in the GSK-1520489A group.Meanwhile,com-pared with the GC group,mOB proliferation decreased(P<0.05)and apoptosis increased significantly(P<0.01)in the GC+GSK-1520489A group.(3)After overexpression of PKMYT1,in comparison with the control group,mOB proliferation increased(P<0.001)but apoptosis did not increase significantly(P>0.05)in the OE group.Moreover,compared with the GC group,mOB proliferation increased(P<0.001)but apoptosis decreased(P<0.001)significantly in the OE+GC group.(4)In hOBs extracted from human femoral head tissues,qPCR and WB results showed that PKMYT1 expression of the hSANFH group was significantly lower than the control group(P<0.001).Conclusion Down regulation of PKMYT1 expression promotes GC-induced apoptosis of mOBs.Conversely,over expression of PK-MYT1 inhibits GC-induced apoptosis of mOBs.Therefore,PKMYT1 may serve as a potential target for the early treatment of SANFH.