BACKGROUND:Several observational studies have found a strong association between thyroid function and its related disorders and osteoporosis,but the causal relationship is unclear.OBJECTIVE:To ascertain the causal relationship between genetically predicted thyroid function and its associated disorders,as well as osteoporosis,through the Mendelian randomization analysis with extensive pooled genetic data.METHODS:Pooled data from genome-wide association studies were employed to investigate the causal relationship between thyroid function and its associated disorders and osteoporosis.This was achieved through the utilization of the inverse variance weighting method as the primary Mendelian randomization analysis method,in conjunction with the MR-Egger method,weighted median method,simple model method,and weighted model method.A two-step mediated Mendelian randomization analysis was used to calculate the mediating effect of drug-mediated thyroid dysfunction on osteoporosis and the mediating proportion.Subsequently,sensitivity analyses were conducted using the MR-Egger intercept test and MR-PRESSO to detect multiplicity,Cochran's Q test to detect heterogeneity,and leave-one-out to perform sensitivity analyses.RESULTS AND CONCLUSION:(1)The results of the inverse variance weighting method showed that thyroid function had an effect on bone mineral density,and that thyrotropin,free triiodothyronine on bone mineral density,free thyroxine,and subclinical hyperthyroidism all had a causal effect on bone mineral density.(2)In addition,mediation analyses revealed a potential mediating effect of carbimazole in the causal relationship between hyperthyroidism and the risk of developing osteoporosis,as well as a potential mediating effect of levothyroxine sodium in the causal relationship between hypothyroidism and the risk of developing osteoporosis.(3)In conclusion,thyrotropin,which is high in the normal range,has been demonstrated to increase bone mineral density.Conversely,free triiodothyronine and free thyroxine,which are also high within the normal range,as well as subclinical hyperthyroidism,have been shown to decrease bone mineral density.The risk of developing osteoporosis is partially mediated by the pathway of taking the therapeutic medication in the context of pharmacologic treatment of thyroid dysfunction.(4)The present study primarily focuses on European population data.However,given the commonality of the genetic background and the generalizability of genome-wide data analysis methods,it is of significant importance to explore the pathogenesis of osteoporosis in the Chinese population,develop effective interventions,and provide genetic counseling.

BACKGROUND:Several observational studies have found a strong association between thyroid function and its related disorders and osteoporosis,but the causal relationship is unclear.OBJECTIVE:To ascertain the causal relationship between genetically predicted thyroid function and its associated disorders,as well as osteoporosis,through the Mendelian randomization analysis with extensive pooled genetic data.METHODS:Pooled data from genome-wide association studies were employed to investigate the causal relationship between thyroid function and its associated disorders and osteoporosis.This was achieved through the utilization of the inverse variance weighting method as the primary Mendelian randomization analysis method,in conjunction with the MR-Egger method,weighted median method,simple model method,and weighted model method.A two-step mediated Mendelian randomization analysis was used to calculate the mediating effect of drug-mediated thyroid dysfunction on osteoporosis and the mediating proportion.Subsequently,sensitivity analyses were conducted using the MR-Egger intercept test and MR-PRESSO to detect multiplicity,Cochran's Q test to detect heterogeneity,and leave-one-out to perform sensitivity analyses.RESULTS AND CONCLUSION:(1)The results of the inverse variance weighting method showed that thyroid function had an effect on bone mineral density,and that thyrotropin,free triiodothyronine on bone mineral density,free thyroxine,and subclinical hyperthyroidism all had a causal effect on bone mineral density.(2)In addition,mediation analyses revealed a potential mediating effect of carbimazole in the causal relationship between hyperthyroidism and the risk of developing osteoporosis,as well as a potential mediating effect of levothyroxine sodium in the causal relationship between hypothyroidism and the risk of developing osteoporosis.(3)In conclusion,thyrotropin,which is high in the normal range,has been demonstrated to increase bone mineral density.Conversely,free triiodothyronine and free thyroxine,which are also high within the normal range,as well as subclinical hyperthyroidism,have been shown to decrease bone mineral density.The risk of developing osteoporosis is partially mediated by the pathway of taking the therapeutic medication in the context of pharmacologic treatment of thyroid dysfunction.(4)The present study primarily focuses on European population data.However,given the commonality of the genetic background and the generalizability of genome-wide data analysis methods,it is of significant importance to explore the pathogenesis of osteoporosis in the Chinese population,develop effective interventions,and provide genetic counseling.

BACKGROUND:At present,modern medical treatment has certain limitations on the treatment of knee osteoarthritis.Traditional Chinese medicine alkaloids can effectively prevent and treat knee osteoarthritis through various mechanisms. OBJECTIVE:To review the mechanism of alkaloids in traditional Chinese medicine in the prevention and treatment of knee osteoarthritis,providing a scientific basis for the clinical development of drugs for the treatment of knee osteoarthritis. METHODS:CNKI,WanFang,PubMed,Web of Science and Google Scholar were retrieved for relevant literature published from database inception to May 2024.The key words were"knee osteoarthritis""osteoarthritis""osteoclast""chondrocyte""alkaloids"in Chinese and English.Duplicates and obsolete non-referenced literature were excluded,and a total of 68 eligible papers were included for further review. RESULTS AND CONCLUSION:Although traditional Chinese medicine has a long history of treating knee osteoarthritis,only a small number of natural compounds are in the preclinical stage of research against knee osteoarthritis.Alkaloids have a greater potential for the prevention and treatment of knee osteoarthritis,among which,sophocarpidine,oxymatrine,sinomenine,and betaine have been shown to be effective in the prevention and treatment of knee osteoarthritis by modulating multiple signaling pathways.Alkaloids can delay the progression of knee osteoarthritis by inhibiting inflammatory response,exerting antioxidant response,inhibiting chondrocyte apoptosis,promoting chondrocyte proliferation,and inhibiting osteoclast formation and differentiation.

Objective To investigate the effect of vitamin B12(VB12)on the expression of zonula occludens-1(ZO-1)in house dust mite(HDM)-treated human airway epithelial cell line(Beas-2b)and its underlying mechanism.Methods Beas-2b cells were cultured in DMEM high-glucose medium containing 10%fetal bovine serum.The cells were divided into four groups:control,VB12,HDM,and VB12+HDM.Beas-2b cells were trans-fected with lentiviruses carrying NC-siRNA,ATG5-siRNA,BECN1-siRNA,and mCherry-EGFP-LC3.After 12 hours of transfection(MOI=20),the medium was replaced with fresh medium,and stable transfected cell lines were selected using puromycin(1 μg/mL).Cells were stimulated with VB12(20 μg/mL)and HDM(50 μg/mL)for 24 hours.The protein levels of ZO-1,autophagy-related protein 5(ATG5),BECN1 and microtubule-associated protein light chain 3(LC3)were detected by immunofluorescence and Western blot.Autophagy in human airway epithelial cells was observed using confocal microscopy.Results Compared with the control group,the expression of ZO-1 in the HDM group was lower(P<0.05),while the expressions of ATG5,BECN1,and LC3 were higher(P<0.05).Compared with the HDM group,the VB12+HDM group showed increased ZO-1 expression(P<0.05),decreased expressions of ATG5,BECN1,and LC3(P<0.01),and reduced autophagosome formation(P<0.05).In ATG5-and BECN1-knockdown cell lines,ZO-1 expression increased after HDM treatment(P<0.05).Conclusion Vb12 can enhance ZO-1 expression in HDM-treated human airway epithelial cells by down-regulating autophagy,and its mechanism is associated with the ATG5 and BECN1 signaling pathways.

Objective To investigate the mechanism of autophagy induced by House dust mites(HDM)on airway epithelial tight junction through β-catenin-Snail signaling pathway.Methods Human bronchial epithelial cells(16HBE)were stimulated with HDM at different time points(0,3,6,12,24,48 h)and different concen-trations(0,40,100,200 μg/mL)to screen the appropriate stimulation concentration and stimulation time.16HBE cells were treated with oxidative stress inhibitor N-acetylcysteine(NAC),autophagy inhibitor 3-methylad-enine(3-MA),HDM,and their combinations.Cells were transfected with mCherry-EGFP-LC3B,Beclin-1-siRNA,and ATG14-siRNA lentivirus and then stimulated with NAC and HDM.Immunofluorescence was used to detect the expression levels of autophagy-related protein LC3B,tight junction-related proteins Occludin,and ZO-1 in airway epithelial cells.The level of reactive oxygen species(ROS)was detected by using DCFH-DA in each group.The protein expression levels of Occludin,ZO-1,LC3B,Beclin-1,ATG5,ATG14,P62,Snail,β-catenin and p-β-catenin were detected by Western blot method.Results Immunofluorescence results showed that compared with the control group,200 μg/mL HDM stimulation induced cellular autophagy,increased the expression level of LC3B protein,and promoted the level of ROS,all with statistical significances(all P<0.05).Compared with the HDM group,the HDM+3-MA,HDM+ATG14-si,and HDM+Beclin-1-si groupsall showed significantincreases in the expression levels of tight junction-related proteins Occludin and ZO-1(P<0.05).The HDM+NAC group demonstrated significant decreases both in the level of ROS andin the expression level of LC3B protein.Western blot results revealed that compared with HDM,3-MA and autophagy protein low-expression beads(Beclin-1-si,ATG14-si)attenuated HDM-induced cellular autophagy(P<0.05),inhibited HDM-induced upregulation of Snail and p-β-catenin expression,and improved HDM-induced decreases in Occludin and ZO-1(P<0.05).Moreover,compared with the HDM group,the NAC+HDM group exhibited significant decreases both in the conversion of LC3BⅠ to LC3BⅡ(P<0.001)in the protein levels of Snail,p-β-catenin,Beclin-1 and ATG14(P<0.01),but significant increases in the protein levels of Occludin and ZO-1(P<0.05).Conclusion HDM affects the tight connections between airway epithelial cells by inducing autophagy,which may be attributed to the β-catenin-Snail signaling pathway.

BACKGROUND:In recent years,a number of studies have confirmed that gut microbiome regulates bone metabolism through multiple pathways,and this field has become a research hotspot in orthopedics and microbiology.However,there is still no literature metrology and visual analysis on this field.OBJECTIVE:To explore the research status,hot spots and development trends in the field of gut microbiome regulation of bone metabolism,and to provide certain data support and reference for subsequent studies.METHODS:The Web of Science core collection database was used as the retrieval platform to retrieve the related literature in the field of intestinal flora regulating bone metabolism from 2004 to 2024.Citespace software was used to visually analyze the included literature and generate a visual atlas.RESULTS AND CONCLUSION:(1)A total of 1,035 papers were included in this study.In the past 20 years,the number of publications in the field of gut microbiome regulation of bone metabolism has shown a significant growth trend,with the United States and China dominating research and publication activities in this field.Harvard University and the University of California system are the research institutions with the highest number of published papers and research centrality in this area,and Professor Pacifici R of Emory University is the most prolific author.(2)Inflammatory bowel disease,chain fatty acids,bone marrow are the core keywords in this field.Postmenopausal osteoporosis,rheumatoid arthritis,oxidative stress,mitochondrial dysfunction are the latest research frontiers in this field.(3)Among the top 10 cited papers,4 discussed the mechanism of short-chain fatty acids affecting bone metabolism;3 investigated the pathogenesis and therapeutic potential of intestinal flora in postmenopausal osteoporosis,glucocorticoid-induced osteoporosis,and senile osteoporosis;1 discussed the relationship between intestinal inflammation,intestinal flora,parathyroid hormone,and bone metabolism;and 1 examined the effects of Lactobacillus rhamnosus and T cells on the gut microbiome and bone metabolism.(4)NUTRIENTS has the most papers,while ENDOCRINOLOGY& METABOLISM has the most citations.(5)Based on literature co-citation analysis and keywords,further exploration is needed on the specific pathogenesis and treatment strategies of gut microbiome in postmenopausal osteoporosis and rheumatoid arthritis,revealing the molecular mechanism of regulating gut microbiota to inhibit oxidative stress and improve mitochondrial dysfunction affecting bone metabolism,and translating mechanism research into clinical application,which all constitute the future research directions and trends in this field.

Objective To investigate the effect of vitamin B12(VB12)on the expression of zonula occludens-1(ZO-1)in house dust mite(HDM)-treated human airway epithelial cell line(Beas-2b)and its underlying mechanism.Methods Beas-2b cells were cultured in DMEM high-glucose medium containing 10%fetal bovine serum.The cells were divided into four groups:control,VB12,HDM,and VB12+HDM.Beas-2b cells were trans-fected with lentiviruses carrying NC-siRNA,ATG5-siRNA,BECN1-siRNA,and mCherry-EGFP-LC3.After 12 hours of transfection(MOI=20),the medium was replaced with fresh medium,and stable transfected cell lines were selected using puromycin(1 μg/mL).Cells were stimulated with VB12(20 μg/mL)and HDM(50 μg/mL)for 24 hours.The protein levels of ZO-1,autophagy-related protein 5(ATG5),BECN1 and microtubule-associated protein light chain 3(LC3)were detected by immunofluorescence and Western blot.Autophagy in human airway epithelial cells was observed using confocal microscopy.Results Compared with the control group,the expression of ZO-1 in the HDM group was lower(P<0.05),while the expressions of ATG5,BECN1,and LC3 were higher(P<0.05).Compared with the HDM group,the VB12+HDM group showed increased ZO-1 expression(P<0.05),decreased expressions of ATG5,BECN1,and LC3(P<0.01),and reduced autophagosome formation(P<0.05).In ATG5-and BECN1-knockdown cell lines,ZO-1 expression increased after HDM treatment(P<0.05).Conclusion Vb12 can enhance ZO-1 expression in HDM-treated human airway epithelial cells by down-regulating autophagy,and its mechanism is associated with the ATG5 and BECN1 signaling pathways.

BACKGROUND:In recent years,a number of studies have confirmed that gut microbiome regulates bone metabolism through multiple pathways,and this field has become a research hotspot in orthopedics and microbiology.However,there is still no literature metrology and visual analysis on this field.OBJECTIVE:To explore the research status,hot spots and development trends in the field of gut microbiome regulation of bone metabolism,and to provide certain data support and reference for subsequent studies.METHODS:The Web of Science core collection database was used as the retrieval platform to retrieve the related literature in the field of intestinal flora regulating bone metabolism from 2004 to 2024.Citespace software was used to visually analyze the included literature and generate a visual atlas.RESULTS AND CONCLUSION:(1)A total of 1,035 papers were included in this study.In the past 20 years,the number of publications in the field of gut microbiome regulation of bone metabolism has shown a significant growth trend,with the United States and China dominating research and publication activities in this field.Harvard University and the University of California system are the research institutions with the highest number of published papers and research centrality in this area,and Professor Pacifici R of Emory University is the most prolific author.(2)Inflammatory bowel disease,chain fatty acids,bone marrow are the core keywords in this field.Postmenopausal osteoporosis,rheumatoid arthritis,oxidative stress,mitochondrial dysfunction are the latest research frontiers in this field.(3)Among the top 10 cited papers,4 discussed the mechanism of short-chain fatty acids affecting bone metabolism;3 investigated the pathogenesis and therapeutic potential of intestinal flora in postmenopausal osteoporosis,glucocorticoid-induced osteoporosis,and senile osteoporosis;1 discussed the relationship between intestinal inflammation,intestinal flora,parathyroid hormone,and bone metabolism;and 1 examined the effects of Lactobacillus rhamnosus and T cells on the gut microbiome and bone metabolism.(4)NUTRIENTS has the most papers,while ENDOCRINOLOGY& METABOLISM has the most citations.(5)Based on literature co-citation analysis and keywords,further exploration is needed on the specific pathogenesis and treatment strategies of gut microbiome in postmenopausal osteoporosis and rheumatoid arthritis,revealing the molecular mechanism of regulating gut microbiota to inhibit oxidative stress and improve mitochondrial dysfunction affecting bone metabolism,and translating mechanism research into clinical application,which all constitute the future research directions and trends in this field.

BACKGROUND:In recent years,postmenopausal osteoporosis has been widely concerned by the society.With the gradual deepening of the research on animal models,animal models have become an important means of modern traditional Chinese medicine research as well as the experimental basis.Therefore,it is particularly important to understand the current status,hotspots,and development trend of the research on animal models.OBJECTIVE:To analyze the research status,hotspots,and development trend of animal models of postmenopausal osteoporosis at home and abroad,and to provide a certain theoretical foundation and reference basis for subsequent research.METHODS:Using"Subject=Postmenopausal osteoporosis AND Subject line=Mouse+Rabbit+Dog+Pig+Sheep+Monkey+Fish+Laboratory animals+Animal experimentation"in Chinese as the search formula,we searched for relevant literature published from January 1,1999 to October 1,2023 in CNKI and WanFang databases.Meanwhile,the articles published from January 1,1999 to October 1,2023 in the Web of Science Core Collection database were searched using"TS=(Postmenopausal osteoporosis)AND TS=(mouse OR mice OR rat OR rabbit OR dog OR swine OR pig OR sheep OR monkey OR fish OR flies OR"laboratory animal"OR"experiment animal"as the search formula.CiteSpace software was applied to visualize and analyze the authors,institutions,countries,keywords,and literature co-citations.RESULTS AND CONCLUSION:(1)After analyzing and screening,1 238 documents were included in the CNKI and WanFang databases,and 3 419 documents were included in the Web of Science Core Collection database.The overall number of articles issued since 1999 has been on an upward trend,with the highest research centrality in the United States,the highest number of articles issued in China.Moreover,the institution with the highest research centrality is the University of California.(2)After removing the keywords directly related to the article topics and synthesizing the co-occurrence frequency and centrality,"biomechanics,""Zuo Gui Wan,""alendronate,""breast cancer,"and"biochemical indicators"are in the core of the research field.(3)According to the analysis of co-citations,among the top 10 cited documents,5 of them are related to the treatment measures and clinical efficacy of postmenopausal osteoporosis.(4)Based on the analysis of keywords and co-cited literature,investigations on osteoblast formation and the mechanism of bone formation,the mechanism of metabolomics,the treatment of traditional Chinese medicine,signaling pathway,parathyroid hormone treatment,and sclerostin antibody treatment are the hot research topics now and the future research trends.

Objective To investigate the mechanism of autophagy induced by House dust mites(HDM)on airway epithelial tight junction through β-catenin-Snail signaling pathway.Methods Human bronchial epithelial cells(16HBE)were stimulated with HDM at different time points(0,3,6,12,24,48 h)and different concen-trations(0,40,100,200 μg/mL)to screen the appropriate stimulation concentration and stimulation time.16HBE cells were treated with oxidative stress inhibitor N-acetylcysteine(NAC),autophagy inhibitor 3-methylad-enine(3-MA),HDM,and their combinations.Cells were transfected with mCherry-EGFP-LC3B,Beclin-1-siRNA,and ATG14-siRNA lentivirus and then stimulated with NAC and HDM.Immunofluorescence was used to detect the expression levels of autophagy-related protein LC3B,tight junction-related proteins Occludin,and ZO-1 in airway epithelial cells.The level of reactive oxygen species(ROS)was detected by using DCFH-DA in each group.The protein expression levels of Occludin,ZO-1,LC3B,Beclin-1,ATG5,ATG14,P62,Snail,β-catenin and p-β-catenin were detected by Western blot method.Results Immunofluorescence results showed that compared with the control group,200 μg/mL HDM stimulation induced cellular autophagy,increased the expression level of LC3B protein,and promoted the level of ROS,all with statistical significances(all P<0.05).Compared with the HDM group,the HDM+3-MA,HDM+ATG14-si,and HDM+Beclin-1-si groupsall showed significantincreases in the expression levels of tight junction-related proteins Occludin and ZO-1(P<0.05).The HDM+NAC group demonstrated significant decreases both in the level of ROS andin the expression level of LC3B protein.Western blot results revealed that compared with HDM,3-MA and autophagy protein low-expression beads(Beclin-1-si,ATG14-si)attenuated HDM-induced cellular autophagy(P<0.05),inhibited HDM-induced upregulation of Snail and p-β-catenin expression,and improved HDM-induced decreases in Occludin and ZO-1(P<0.05).Moreover,compared with the HDM group,the NAC+HDM group exhibited significant decreases both in the conversion of LC3BⅠ to LC3BⅡ(P<0.001)in the protein levels of Snail,p-β-catenin,Beclin-1 and ATG14(P<0.01),but significant increases in the protein levels of Occludin and ZO-1(P<0.05).Conclusion HDM affects the tight connections between airway epithelial cells by inducing autophagy,which may be attributed to the β-catenin-Snail signaling pathway.