BACKGROUND:During bone remodeling,bone formation and bone resorption are spatially and temporally coordinated,involving intricate interactions between osteoclasts and osteoblasts.Isoginkgetin,a flavonoid found in Ginkgo biloba,has a wide range of anticancer activity and anti-reactive oxygen species activity;however,the effect of isoginkgetin on osteoclast differentiation is unknown.OBJECTIVE:To study the effect and mechanism of action of isoginkgetin on osteoclastogenesis.METHODS:In vitro studies were performed on mouse bone marrow-derived macrophages,and cell counting kit-8 cytotoxicity assay was used to detect the effect of isoginkgetin on cell viability of bone marrow-derived macrophages.Macrophage colony-stimulating factor and receptor activator of nuclear factor kappa-B ligand were used to induce the differentiation of bone marrow-derived macrophages to osteoclasts.Network pharmacology and molecular docking and molecular dynamics simulations were used to predict the processes and targets of the effects of isoginkgetin on the differentiation of osteoclasts.Tartrate-resistant acid phosphatase staining and F-actin staining were used to detect the effects of isoginkgetin on the differentiation and function of osteoclasts.Western blot and RT-PCR were used to detect the effects of isoginkgetin on the expression of genes and proteins related to osteoclast differentiation,reactive oxygen species,and PI3K/AKT pathways.Fluorescent probes were used to detect cellular and mitochondrial reactive oxygen species levels.Flow cytometry technology was used to detect reactive oxygen species levels in cells.RESULTS AND CONCLUSION:(1)Network pharmacology results showed that isoginkgetin affected osteoporosis mainly through the PI3K-AKT pathway and cellular response to drugs and hypoxia,and GSK3β,ESR1,MCL1 and CCNA2 were the key targets.(2)Cell counting kit-8 and tartrate-resistant acid phosphatase staining results showed that isoginkgetin at 8 μmol/L had the most significant inhibitory effect on osteoclastogenesis in vitro,and F-actin results showed that isoginkgetin inhibited osteoclast cytoskeletal actin ring formation in a concentration-dependent manner.(3)Molecular dynamics simulations showed that isoginkgetin bound well to osteoclastogenesis marker proteins(NFATc1,c-Fos,CTSK,and MMP9).Western blot and RT-PCR results indicated that isoginkgetin inhibited the expression of osteoclastogenesis marker proteins and genes(NFATc1,c-Fos,CTSK,and MMP9).(4)Western blot results showed that isoginkgetin inhibited the phosphorylation level of PI3K/AKT/GSK3β and suppressed osteoclastogenesis by activating the PI3K-AKT-GSK3β pathway.(5)The results of reactive oxygen species assay showed that isoginkgetin significantly reduced receptor activator of nuclear factor kappa-B ligand-induced cellular and mitochondrial reactive oxygen species production,and inhibited the differentiation of bone marrow-derived macrophages to osteoclasts.

BACKGROUND:β-Caryophyllene has a variety of pharmacological activities such as antioxidant,anti-inflammatory and anti-apoptotic,which may have a better therapeutic effect on osteoarthritis.OBJECTIVE:To investigate the effect and mechanism of β-caryophyllene on mouse osteoarthritis.METHODS:Forty C57BL/6J mice were randomly divided into sham group,model group,low-dose β-caryophyllene group and high-dose β-caryophyllene group,with 10 mice in each group.Hulth method was used to construct an osteoarthritis model in the latter three groups.Four weeks after modeling,70 and 140 mg/kg/d β-caryophyllene was intragastrically given in the low-and high-dose β-caryophyllene groups,respectively,and normal saline was given by gavage in the sham group and the model group,once a day,for 4 weeks.After administration,knee joint morphological changes were observed by hematoxylin-eosin staining,serum levels of inflammatory factors(tumor necrosis factor-α,interleukin-1β,interleukin-6,and interleukin-10)were detected by ELISA,and oxidative stress indexes(glutathione peroxidase,superoxide dismutase,and malondialdehyde)were detected by chemiluminescence.The expression levels of key proteins in the Sonic hedgehog(Shh)/glioma associated oncogene homolog 1(Gli1)signaling pathway were detected by immunohistochemistry and western blot.RESULTS AND CONCLUSION:(1)Compared with the sham group,a large number of inflammatory cells infiltrated in the knee joint of mice in the model group,cartilage tissue was seriously damaged,serum levels of tumor necrosis factor-α,interleukin-1β,interleukin-6,interleukin-10 and malondialdehyde were significantly increased(P＜0.01),the activities of glutathione peroxidase and superoxide dismutase were significantly decreased(P＜0.01),and the relative expression levels of Shh and Gli1 in the knee joint were significantly increased(P＜0.01).(2)Compared with the model group,in the low-and high-dose β-caryophyllene groups,inflammatory cell infiltration in the mouse knee joint was decreased,cartilage tissue injury was alleviated,serum levels of tumor necrosis factor-α,interleukin-1 β,interleukin-6 and malondialdehyde were significantly decreased(P＜0.05),the activities of glutathione peroxidase and superoxide dismutase were significantly increased(P＜0.01),and the expression levels of Shh and Gli1 in the knee joint were significantly decreased(P＜0.01).The above-mentioned improvements were more significant in the high-dose β-caryophyllene group than the low-dose β-caryophyllene group.To conclude,β-caryophyllene can improve osteoarthritis,and its mechanism may be related to reducing inflammation and oxidative stress damage by regulating the Shh/Gli1 signaling pathway.

BACKGROUND:Cell-free therapy is a research hotspot in the field of medical cosmetic anti-aging.It is still unknown for paracellular secretion of human umbilical cord mesenchymal stem cell-derived small extracellular vesicles loaded with the antiaging drug α-ketoglutaric acid to delay skin aging.OBJECTIVE:To investigate the effect of the anti-aging agent α-ketoglutarate engineered human umbilical cord mesenchymal stem cell-derived small extracellular vesicles in a D-galactose-induced model of dermal fibroblast senescence.METHODS:(1)Biological characteristics of primary human umbilical cord mesenchymal stem cells were identified by osteogenic-lipogenic differentiation staining and flow cytometry.(2)The small extracellular vesicles derived from human umbilical cord mesenchymal stem cell were obtained by using differential-ultracentrifugation.α-Ketoglutarate-engineered human umbilical cord mesenchymal stem cell-small extracellular vesicles were constructed by electroporation,and biologically characterized by transmission electron microscopy and nanoparticle tracking analyzer,while the encapsulation rate was assessed using high-performance liquid chromatography.(3)The effect of α-ketoglutarate on the proliferative capacity of dermal fibroblasts was assessed by CCK-8 and Edu cell proliferation assay kits.(4)The effect of α-ketoglutarate-engineered human umbilical cord mesenchymal stem cell-small extracellular vesicles on delaying the senescence of dermal fibroblasts was evaluated by reactive oxygen species detection kit,western blot assay,and cellular immunofluorescence.RESULTS AND CONCLUSION:(1)The obtained human umbilical cord mesenchymal stem cell and human umbilical cord mesenchymal stem cell-small extracellular vesicles were biologically compatible.(2)There was no toxic effect on dermal fibroblasts when α-ketoglutarate was used in the concentration range of 0.5-8 mmol/L.(3)D-gal induced senescence in dermal fibroblasts,while α-ketoglutarate-engineered human umbilical cord mesenchymal stem cell-small extracellular vesicles treatment reduced the level of oxidative stress,DNA damage,and collagen loss,which was further verified that α-ketoglutarate-engineered human umbilical cord mesenchymal stem cell-small extracellular vesicles could effectively slow down the skin aging process.

BACKGROUND:The inflammatory response of microglia is closely related to neuronal survival,regeneration,and functional recovery after spinal cord injury.Peroxiredoxin 1 is not only involved in the regulation of oxidative stress,but also has an important effect on cell proliferation,apoptosis,and inflammatory response.OBJECTIVE:To investigate the role and mechanism of peroxiredoxin 1 in the inflammatory response of microglia following spinal cord injury.METHODS:(1)Twelve female C57BL/6 mice were randomly divided into sham-operated(n=6)and spinal cord injury(n=6)groups.The sham-operated group was not modeled and acute spinal cord injury models were constructed in the spinal cord injury group using the modified Allen's method.Spinal cord tissue at the injured site was taken at 7 days after modeling and transcriptome sequencing was performed to identify differentially expressed genes.The expression of peroxiredoxin 1 in spinal cord tissues was verified using western blot and RT-qPCR.(2)Mouse microglia BV2 were divided into two groups:the control group was stimulated with lipopolysaccharide for 6 hours,and in the knockout group,lipopolysaccharide stimulation was applied for 6 hours at 24 hours after peroxiredoxin 1 was knocked down in the cells.RT-qPCR was performed to detect mRNA expression of peroxiredoxin 1,inflammatory factors(interleukin 1β,interleukin 6,inducible nitric oxide synthase,tumor necrosis factor α,C-C motif chemokine ligand 2,and C-X-C motif chemokine ligand 2),and western blot was performed to detect the expression of peroxiredoxin 1,inducible nitric oxide synthase,and reactive oxygen/mitogen-activated protein kinase signaling pathway proteins.Mouse microglia BV2 were treated in two groups:the control group was stimulated by hydrogen peroxide for 4 hours,and the knockout group was stimulated by hydrogen peroxide for 4 hours at 24 hours after knockdown of peroxiredoxin 1.The level of reactive oxygen species was detected by 2,7-dichlorodihydrofluorescein diacetate probe.RESULTS AND CONCLUSION:(1)Results from transcriptome sequencing,western blot and RT-qPCR confirmed that peroxiredoxin 1 expression levels in mouse spinal cord tissues were significantly higher in the spinal cord injury group than the sham-operated group(P＜0.05).(2)Peroxiredoxin 1 knockdown in microglial cells led to decreased expression of peroxiredoxin 1 mRNA and protein(P＜0.05),increased mRNA expression of interleukin 1β,interleukin 6,inducible nitric oxide synthase,tumor necrosis factor α,C-C motif chemokine ligand 2,and C-X-C motif chemokine ligand 2(P＜0.05),increased protein expression of inducible nitric oxide synthase,P-P38,P-JNK and P-ERK proteins(P＜0.05),and increased level of reactive oxygen species(P＜0.05).To conclude,peroxiredoxin 1 regulates microglial inflammation by targeting the reactive oxygen species/mitogen-activated protein kinase signaling pathway.

ObjectiveThis paper aims to observe the protective effect of Huamoyan granules on knee osteoarthritis （KOA） and explore whether its protective effect is oriented toward an anti-inflammatory direction by regulation of macrophage polarization， which can effectively inhibit the progression of pathological inflammatory response， reduce the release of inflammatory pain mediators， and downregulate the protein expression level of transient receptor potential vanilloid 1 （TRPV1）， so as to provide experimental evidence for its clinical application and investigate its action mechanism. MethodsAfter adaptive feeding， Sprague-Dawley （SD） rats were randomly divided into six groups： sham group， model group， celecoxib group， and high， medium， and low-dose synovitis granule groups （9.6， 4.8， 2.4 g·kg^-1）. The administration dose of celecoxib capsules was 20 mg·kg^-1. There were 10 rats in the sham group and 12 rats in the model group and each administration group. A KOA animal model was established by means of intra-articular injection of sodium iodoacetate into the knee joint. From the 10^th day of the experiment， each administration group was given intragastric administration at a dose of 10 mL·kg^-1 for 4 weeks. General conditions of rats in each group were assessed daily. The pressure pain threshold （PPT） to mechanical stimulation and joint diameter were recorded. X-ray examination was performed on the right knee joints of rats for imaging analysis. Enzyme linked immunosorbent assay （ELISA） was performed to detect the tumor necrosis factor-α （TNF-α）， serum interleukin-1β （IL-1β）， and other pro-inflammatory cytokines in rat serum samples， as well as the expression levels of neurogenic inflammatory mediators such as nerve growth factor （NGF） and calcitonin gene-related peptide （CGRP）. Histopathological changes in the knee joint synovial tissues were examined by hematoxylineosin （HE） staining. Safranin O-fast green staining was performed to observe and evaluate the degree of knee cartilage lesions. Western blot was employed to quantitatively analyze TRPV1， p38 mitogen-activated protein kinase （p38 MAPK）， and phosphorylated （p）-p38 MAPK in rat knee synovial tissues. Immunofluorescence （IF） was used to measure and assess M1/M2 macrophage polarization. ResultsCompared with those in the sham group， the circumference and joint diameter of the right knee were markedly enlarged in the model group （P<0.01）， while PPTs of rats showed a significant reduction （P<0.01）. The contents of IL-1β， TNF-α， CGRP， and NGF in rats' serum were significantly elevated （P<0.01）， and the synovial Krenn score was increased （P<0.01）. The Mankin score of cartilage tissue was increased （P<0.01）， and the protein expressions of TRPV1 and p-p38 MAPK/p38 MAPK were significantly upregulated （P<0.01）. The experimental intervention significantly reduced the proportion of pro-inflammatory M1 macrophages in the total macrophage population （P<0.01）， and the percentage of M2 macrophages was decreased （P<0.01）. The M1/M2 macrophage ratio was significantly elevated （P<0.01）. Knee joint diameters of all dose groups of Huamoyan granules and the celecoxib group were reduced （P<0.01） compared with those of the model group， and the PPT recovery speeds in the high and medium-dose groups of Huamoyan granules were more obvious （P<0.05）. The contents of IL-1β， CGRP， and NGF in the rats' serum in all administration groups were significantly reduced （P<0.05， P<0.01）， and the content of TNF-α in rats' serum was significantly reduced （P<0.01）. All dose groups of Huamoyan granules demonstrated significant reductions in both synovial Krenn score （P<0.05， P<0.01） and protein expression of TRPV1 and p-p38 MAPK/p38 MAPK in rats' synovial tissues （P<0.01）. The percentage of M1 macrophages in the synovial tissues of the celecoxib group and all dose groups of Huamoyan granules was decreased （P<0.01）. The percentage of M2 macrophages was increased （P<0.05）， and the M1/M2 ratio was decreased （P<0.01）. ConclusionHuamoyan granules can alleviate the inflammatory response of KOA， reduce the release of inflammatory pain mediators， and downregulate TRPV1 protein expression by regulating macrophage polarization. Its mechanism may be related to the TRPV1/p38 MAPK signaling pathway， thereby achieving the effect of improving peripheral pain hypersensitivity in KOA.

Alzheimer's disease （AD） is a common type of dementia， primarily characterized by cognitive and behavioral impairments as well as deficits in learning and memory. The progression of AD has imposed a significant economic burden on society and families. However， its exact pathogenesis has not yet been fully elucidated. Currently， available therapeutic drugs are limited and are often accompanied by serious adverse effects. Traditional Chinese medicines （TCMs） and their extracts are mostly natural products and possess advantages such as multi-pathway regulation and relatively few adverse reactions. Experimental studies have shown that TCMs exhibit great potential in the prevention and treatment of AD. For example， Huanglian Jieduang， Danggui Shaoyaosan， Kaixin San， Liuwei Dihuangwan， Buyang Huanwutang， as well as Ginseng Radix et Rhizoma， Astragali Radix， Uncariae Ramulus cum Uncis， Coptidis Rhizoma， Gardeniae Fructus， Ginkgo Folium， Salviae Miltiorrhizae Radix et Rhizoma， and Curcumae Longae Rhizoma， can reduce β-amyloid deposition， inhibit excessive Tau protein phosphorylation， restore mitochondrial function， alleviate oxidative stress， suppress neuroinflammation and apoptosis， repair synaptic function， and improve gut microbiota. This article mainly summarizes the effects of several TCMs and compound prescriptions on AD， aiming to provide a reference for subsequent TCM-based treatment of AD.

This paper systematically reviewed the concept of authentication studies on traditional Chinese medicine （TCM） classics and the research achievements of scholars across historical and contemporary periods. We categorized the authentication studies on TCM classics into four types， including work-oriented authentication research， metho-dological studies on authentication， extended authentication research， and single-book authentication. Multiple methods were applied comprehensively， including investigating bibliographic documents of successive dynasties， analyzing the academic contents of medical books， studying the textual characteristics of medical books， examining the cited references in medical books， verifying the biographies of authors， and analyzing the interpolations and accretions in medical books， to distinguish the authenticity of TCM classics. The academic value of authenticity identification of TCM classics is concluded in three aspects，i.e. it serves as an important means to distinguish authenticity from falsehood in TCM classics， an important guarantee for inheriting the essence of TCM literature， and a key to unlocking the academic treasure trove of TCM classics and achieving inheritance-based innovation， which will lay a solid documentary foundation for constructing identification methodologies and standardized systems.

ObjectiveTo investigate the migration and distribution characteristics of chemical constituents in blood and hippocampal tissues before and after vinegar processing of Citri Reticulatae Pericarpium Viride（CRPV）， and to explore the potential material basis and mechanisms underlying their regulatory effects on emotional disorders by comparing the effects of raw and vinegar-processed products of CRPV. MethodsUltra-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry（UPLC-Q-TOF-MS/MS） was employed to characterize and identify the chemical constituents of raw and vinegar-processed products of CRPV extracts， as well as their migrating components in blood and hippocampal tissues after oral administration. Reference standards， databases， and relevant literature were utilized for compound annotation， with data processing performed using PeakView 1.2 software. Seventy male C57BL/6 mice were randomly divided into seven groups， including the blank group， model group， diazepam group（2.5 mg·kg^-1）， raw CRPV low/high dose groups（0.6， 1.2 g·kg^-1）， and vinegar-processed CRPV low/high dose groups（0.6， 1.2 g·kg^-1）， with 10 mice per group. Except for the blank group， all other groups underwent chronic restraint stress（2 h·d^-1） for 20 d. Each drug-treated group received oral administration at the predetermined dose starting 10 d after modeling， with a total treatment duration of 10 d. Following model-based drug administration， mice underwent open-field， forced swimming， and elevated plus maze tests. After anesthesia with isoflurane， whole brains were collected from each group of mice， and hippocampi were dissected. Reactive oxygen species（ROS） level in hippocampal tissues was quantified by enzyme-linked immunosorbent assay（ELISA）. Hematoxylin-eosin（HE） staining was used to observe hippocampal tissue morphology. Immunofluorescence was performed to detect neuronal nuclei（NeuN） and peroxisome proliferator-activated receptor alpha（PPARα） expressions in hippocampal tissue. Then， pharmacodynamic evaluations were conducted to assess the effects of raw and vinegar-processed CRPV on mood disorders， exploring the potential mechanisms. ResultsVinegar processing caused significant changes in the chemical composition of CRPV， with 18 components showing increased relative content and 35 components showing decreased relative content. The primary changes occurred in flavonoid compounds， including 20 flavonoids， 20 flavonoid glycosides， 3 triterpenes， 3 phenolic acids， 1 alkaloid， and 6 other compounds. Twenty-one components were detected in blood（15 methoxyflavones， 4 flavonoid glycosides， and 2 phenolic acids）， with 17 shared between raw and vinegar-processed CRPV. Seven components reached hippocampal tissues（all common to both forms）. In regulating emotional disorders， Vinegar-processed CRPV exhibited superior antidepressant-like effects compared to raw products. HE staining revealed that both treatments improved hippocampal neuronal morphology， particularly in the damaged CA1 and CA3 regions. Immunofluorescence and ELISA analyses demonstrated that both raw and vinegar-processed CRPV significantly modulated NeuN and PPARα expressions in hippocampal tissue while alleviating oxidative stress induced by excessive ROS（P<0.05）. ConclusionThe chemical composition of CRPV undergoes changes after vinegar processing， but the migrating components in blood and hippocampus are primarily methoxyflavonoids. These components may serve as the potential material basis for activating the PPARα pathway， thereby negatively regulating ROS generation in the hippocampus， reducing oxidative stress， and promoting the development of NeuN-positive neurons. These findings provide experimental evidence for enhancing quality standards， pharmacodynamic material research， and active drug development of raw and vinegar-processed CRPV.

Objective: To investigate the epidemiological characteristics and spatial-temporal clustering of severe fever with thrombocytopenia syndrome (SFTS) in Huai'an City, Jiangsu Province from 2011 to 2024, so as to provide a basis for optimizing local SFTS prevention and control strategies, and identifying high-risk areas and key populations. Methods: Data on SFTS incidence and deaths in Huai'an City from 2011 to 2024 were collected from the Infectious Disease Reporting Information System of the Chinese Disease Prevention and Control Information System. The reported incidence, mortality, and fatality rates were calculated. Descriptive analysis was performed on temporal, population, and regional distribution. The average annual percent change (AAPC) was used to analyze the trend in the reported incidence of SFTS. Global and local spatial autocorrelation analyses were employed to examine the spatial distribution patterns and spatial association patterns of SFTS incidence while spatio-temporal scanning analyses was used to assess the spatial-temporal clustering of SFTS. Results: A total of 337 SFTS cases were reported in Huai'an City from 2011 to 2024, with the reported incidence rising from 0.17/100 000 to 1.88/100 000. There were 20 deaths, with an average annual mortality of 0.03/100 000, and a fatality rate of 5.93%. The incidence showed obvious seasonality, with a peak in May and June (148 cases, accounting for 43.92%). Spring and summer accounted for 107 cases (31.75%) and 159 cases (47.18%), respectively. The reported SFTS cases were mainly male, farmers, and individuals aged ≥41 years, accounting for 56.38%, 79.23%, and 96.74%, respectively. The population distribution of death cases was basically consistent with that of incident cases. Xuyi County was a high-incidence area, with a total of 332 reported cases, accounting for 98.52%. All death cases were reported in this county. Spatial autocorrelation analyses revealed a positive spatial correlation in SFTS incidence from 2019 to 2024, with Moran's I values ranging from 0.214 to 0.336 (all P<0.05). Heqiao Town, Tianquanhu Town, and Guiwu Town in Xuyi County were identified as high-high clustering areas. Spatio-temporal scanning analyses showed that cluster 1 was consistent with the high-high clustering areas, with an aggregation time from the second quarter of 2019 to the second quarter of 2022. Conclusions From 2011 to 2024, the reported incidence of SFTS in Huai'an City showed an upward trend, with a high incidence in spring and summer. Males, farmers, and the middle-aged and elderly population were the key populations for prevention and control. Xuyi County was the key area for prevention and control.

ObjectiveThis study aims to investigate the action mechanism by which Xiaozheng Zhitong paste （XZP） alleviates bone cancer pain （BCP） by regulating programmed death protein 1 （PD-1）/programmed death-ligand 1 （PD-L1） pathway-induced osteoclast formation. MethodsThirty female C57BL/6 mice were randomly allocated into the following groups （n=6 per group）： normal control group， model group， low‑dose XZP group （31.5 g·kg^-1）， high‑dose XZP group （63 g·kg^-1）， and PD‑1 inhibitor （Niv） group. A bone cancer pain （BCP） model was established by injecting Lewis lung carcinoma cells. Mice in the normal control and model groups received topical application of a blank paste matrix at the wound site. Mice in the low‑ and high‑dose XZP groups were treated with XZP applied topically twice daily. Mice in the Niv group were topically administered the blank paste matrix and additionally received Niv via tail‑vein injection every two days. All interventions were continued for 21 days. During this period， behavioral tests were performed to assess mechanical， motor， and thermal nociceptive sensitivities. After 21 days， all mice were euthanized， and bone tissue from the operated side was collected for sectioning and preservation. Tartrate‑resistant acid phosphatase （TRAP） staining was used to evaluate osteoclast expression in the lesioned bone tissue. Immunohistochemistry was performed to detect the expression of Runt‑related transcription factor 2 （Runx2） in the lesioned bone tissue. Immunofluorescence was employed to assess the expression of PD‑1 and PD‑L1 in the lesioned bone tissue. ResultsCompared with the normal group， the model group showed significantly decreased limb mechanical withdrawal threshold， spontaneous paw flinching， and thermal withdrawal latency （P<0.01）， increased number of osteoclasts in the lesioned bone tissue （P<0.01）， and reduced expression of Runx2 （P<0.01）. Compared with the model group， the BCP mice in the XZP low-dose group， XZP high-dose group， and Niv group exhibited increased limb mechanical withdrawal threshold， movement scores， and thermal withdrawal latency （P<0.01）. The XZP low-dose group showed no significant changes in osteoclast number or Runx2 expression， while the XZP high-dose group and Niv group demonstrated significantly reduced osteoclast numbers （P<0.01） and significantly increased Runx2 expression （P<0.01）. In the lesioned bone tissue of BCP mice， the XZP low-dose group showed no significant decrease in the percentage of PD-1 expression， but a decrease in the percentage of PD-L1 expression （P<0.05）. In contrast， both the XZP high-dose group and the Niv group exhibited significant reductions in the percentages of PD-1 and PD-L1 expression （P<0.01）. ConclusionXZP alleviates the pain of mice with BCP by blocking the PD-1/PD-L1 pathway to inhibit osteoclastogenesis.