Achondroplasia (ACH), the most common skeletal dysplasia in humans, is caused by gain-of-function mutations in fibroblast growth factor receptor 3 (FGFR3). Activation of FGFR3 and its downstream signaling pathways lead to disturbed chondrogenesis in ACH. Nevertheless, the pathogenic mechanism of ACH has yet not been fully elucidated. Previous studies have indicated that FGF and BMP signaling may have opposing actions on the growth plate development. To clarify the crosstalk between FGFR3 and activin receptor-like kinase 3 (ALK3) signaling in ACH, we generated caALK3col2-ACH mice expressing a constitutively active mutant of ALK3 in the chondrocytes of mice with ACH resulting from a Gly369Cys mutation in FGFR3. Unexpectedly, these mice exhibited a more severe chondrodysplasia phenotype than ACH mice, as evidenced by a greater decrease in chondrocyte proliferation and impaired hypertrophy of chondrocytes in the growth plates. These changes were correlated with an increased expression of p21 and activation of ERK/MAPK pathway. This study provides an in vivo genetic demonstration of the imbalanced interaction between the FGFR3 and ALK3 signaling pathways in the growth plate of caALK3col2-ACH mice, suggesting that the ERK/MAPK pathway play an essential role in growth plate chondrogenesis.

Purpose: To identify the risk factors for training-related lower extremity muscle injuries in young males by a non-invasive method of body composition analysis. Methods: A total of 282 healthy young male volunteers aged 18- 20 years participated in this cohort study. Injury location, degree, and injury rate were adjusted by a questionnaire based on the overuse injury assessment methods used in epidemiological studies of sports injuries. The occurrence of training injuries is monitored and diagnosed by physicians and treated accordingly. The body composition was measured using the BodyStat QuadScan 4000 multifrequency Bio-impedance system at 5, 50, 100 and 200 kHz to obtain 4 impedance values. The Shapiro-Wilk test was used to check whether the data conformed to a normal distribution. Data of normal distribution were shown as mean +/- SD and analyzed by t-test, while those of non-normal distribution were shown as median (Q1, 1 , Q3) 3 ) and analyzed by Wilcoxon rank sum test. The receiver operator characteristic curve and logistic regression analysis were performed to investigate risk factors for developing training-related lower extremity injuries and accuracy. Results: Among the 282 subjects, 78 (27.7%) developed training injuries. Lower extremity training injuries revealed the highest incidence, accounting for 23.4% (66 cases). These patients showed higher percentages of lean body mass (p = 0.001), total body water (TBW, p = 0.006), extracellular water (p = 0.020) and intracellular water (p = 0.010) as well as a larger ratio of basal metabolic rate/total weight (p = 0.006), compared with those without lower extremity muscle injuries. On the contrary, the percentage of body fat (p = 0.001) and body fat mass index (p = 0.002) were lower. Logistic regression analysis showed that TBW percentage > 65.35% (p = 0.050, odds ratio = 3.114) and 3rd space water > 0.95% (p = 0.045, odds ratio = 2.342) were independent risk factors for lower extremity muscle injuries. Conclusion: TBW percentage and 3rd space water measured with bio-impedance method are potential risk factors for predicting the incidence of lower extremity muscle injuries in young males following training. (c) 2024 Chinese Medical Association. Production and hosting by Elsevier B.V.

Physical therapy is extensively employed in clinical settings. Nevertheless, the absence of suitable animal models has resulted in an incomplete understanding of the in vivo mechanisms and cellular distribution that respond to physical stimuli. The objective of this research was to create a mouse model capable of indicating the cells affected by physical stimuli. In this study, we successfully established a mouse line based on the heat shock protein 70 (Hsp70) promoter, wherein the expression of CreERT2 can be induced by physical stimuli. Following stimulation of the mouse tail, ear, or cultured calvarias with heat shock (generated by heating, ultrasound, or laser), a distinct Cre-mediated excision was observed in cells stimulated by these physical factors with minimal occurrence of leaky reporter expression. The application of heat shock to Hsp70-CreERT2; FGFR2-P253R double transgenic mice or Hsp70-CreERT2 mice infected with AAV-BMP4 at calvarias induced the activation of Cre-dependent mutant FGFR2-P253R or BMP4 respectively, thereby facilitating the premature closure of cranial sutures or the repair of calvarial defects. This novel mouse line holds significant potential for investigating the underlying mechanisms of physical therapy, tissue repair and regeneration, lineage tracing, and targeted modulation of gene expression of cells in local tissue stimulated by physical factor at the interested time points.

Macrophages are heterogenic phagocytic cells that play distinct roles in physiological and pathological processes. Targeting different types of macrophages has shown potent therapeutic effects in many diseases. Although many approaches are developed to target anti-inflammatory macrophages, there are few researches on targeting pro-inflammatory macrophages, which is partially attributed to their non-s pecificity phagocytosis of extracellular substances. In this study, a novel recombinant protein is constructed that can be anchored on an exosome membrane with the purpose of targeting pro-inflammatory macrophages via antigen recognition, which is named AnCar-ExoLaIMTS . The data indicate that the phagocytosis efficiencies of pro-inflammatory macrophages for different AnCar-ExoLaIMTS show obvious differences. The AnCar-ExoLaIMTS3 has the best targeting ability for pro-inflammatory macrophages in vitro and in vivo. Mechanically, AnCar-ExoLaIMTS3 can specifically recognize the leucine-rich repeat domain of the TLR4 receptor, and then enter into pro-inflammatory macrophages via the TLR4-mediated receptor endocytosis pathway. Moreover, AnCar-ExoLaIMTS3 can efficiently deliver therapeutic cargo to pro-inflammatory macrophages and inhibit the synovial inflammatory response via downregulation of HIF-1α level, thus ameliorating the severity of arthritis in vivo. Collectively, the work established a novel gene/drug delivery system that can specifically target pro-inflammatory macrophages, which may be beneficial for the treatments of arthritis and other inflammatory diseases.

骨应力损伤(bone stress injury, BSI)是由于跑步和军事训练中过度使用引起的常见损伤.它包含从应激反应开始,发展为应激性骨折,最终导致完全性骨折的连续病理过程.由于BSI在跑步和军事训练人群中有高发病率 [1],且多达 22％的为复发性[2] ,需要较长的恢复时间,因此BSI经常导致训练人群运动生涯的终结[3].目前,人们对BSI并不完全了解,其病理生理学仍有一定的推测性.越来越多的研究者达成了共识,认为BSI是由于负荷引起的骨组织微损伤的形成和去除之间的不平衡导致的,因此,BSI的风险因素可以分为影响骨负荷的因素和影响骨抗负荷能力的因素.BSI的风险因素是影响BSI预防策略和治疗策略制定的中心环节,本文旨在对BSI的风险因素进行综述.

Intervertebral disc degeneration (IVDD) can cause low back pain, a major public health concern. IVDD is characterized with loss of cells especially those in nucleus pulposus (NP), due to the limited proliferative potential and regenerative ability. Few studies, however, have been carried out to investigate the in vivo proliferation events of NP cells and the cellular contribution of a specific subpopulation of NP during postnatal growth or regeneration. We generated FGFR3-3*Flag-IRES-GFP mice and crossed FGFR3-CreERT2 mice with Rosa26-mTmG, Rosa26-DTA and Rosa26-Confetti mice, respectively, to perform inducible genetic tracing studies. Expression of FGFR3 was found in the outer region of NP with co-localized expressions of proliferating markers. By fate mapping studies, FGFR3-positive (FGFR3+) NP cells were found proliferate from outer region to inner region of NP during postnatal growth. Clonal lineage tracing by Confetti mice and ablation of FGFR3·+ NP cells by DTA mice further revealed that the expansion of the FGFR3+ cells was required for the morphogenesis and homeostasis of postnatal NP. Moreover, in degeneration and regeneration model of mouse intervertebral disc, FGFR3+ NP cells underwent extensive expansion during the recovery stage. Our present work demonstrates that FGFR3+ NP cells are novel subpopulation of postnatal NP with long-existing proliferative capacity shaping the adult NP structure and participating in the homeostasis maintenance and intrinsic repair of NP. These findings may facilitate the development of new therapeutic approaches for IVD regeneration.

Ferroptosis is a new type of programmed cell death with unique morphological, biochemical, and genetic features. From the initial study of histomorphology to the exploration of subcellular organelles and even molecular mechanisms, a net connecting ferroptosis and fibrosis is being woven and formed. Inflammation may be the bridge between both processes. In this review, we will discuss the ferroptosis theory and process and the physiological functions of ferroptosis, followed by a description of the pathological effects and the underlying mechanisms of ferroptosis in the pathogenesis of tumorigenesis, ischemic damage, degenerative lesions, autoimmune diseases, and necroinflammation. We then focus on the role of ferroptosis in the fibrosis process in the liver, lung, kidney, heart, and other organs. Although the molecular mechanism of ferroptosis has been explored extensively in the past few years, many challenges remain to be resolved to translate this information into antifibrotic practice, which is becoming a promising new direction in the field of fibrotic disease prevention and treatment.

The intervertebral disc (IVD) is the largest avascular tissue. Hypoxia-inducible factors (HIFs) play essential roles in regulating cellular adaptation in the IVD under physiological conditions. Disc degeneration disease (DDD) is one of the leading causes of disability, and current therapies are ineffective. This study sought to explore the role of HIFs in DDD pathogenesis in mice. The findings of this study showed that among HIF family members, Hif1α was significantly upregulated in cartilaginous endplate (EP) and annulus fibrosus (AF) tissues from human DDD patients and two mouse models of DDD compared with controls. Conditional deletion of the E3 ubiquitin ligase Vhl in EP and AF tissues of adult mice resulted in upregulated Hif1α expression and age-dependent IVD degeneration. Aberrant Hif1α activation enhanced glycolytic metabolism and suppressed mitochondrial function. On the other hand, genetic ablation of the Hif1α gene delayed DDD pathogenesis in Vhl-deficient mice. Administration of 2-methoxyestradiol (2ME2), a selective Hif1α inhibitor, attenuated experimental IVD degeneration in mice. The findings of this study show that aberrant Hif1α activation in EP and AF tissues induces pathological changes in DDD, implying that inhibition of aberrant Hif1α activity is a potential therapeutic strategy for DDD.

目的 通过对新入学学员实施人体成分分析及军事训练伤调查,分析人体成分与军事训练伤的关系.方法 从某陆军院校新训学员中随机抽取146名新生为研究对象(包括部队生源的战士学员和高考生源的非战士学员),其中男性111名,战士学员12名,非战士学员99名;女性35名,战士学员31名,非战士学员4名.新训前,用人体成分分析仪测量体重、体脂、基础代谢、水分、肌肉、蛋白质含量、骨量、内脏脂肪及体重指数(BMI)等多项数据.新训后,通过调查问卷收集军事训练伤情况,使用logistic回归(向前:Wald)分析训练伤发生的保护因素.结果 大部分学生BMI在正常范围内,但男性肥胖前期者百分比明显高于女性(17.1％vs.2.8％,P<0.05).新训前,战士学员训练伤发生率较高(男、女分别为45.4％,25.8％),男性及女性战士学员人体成分综合评分均明显高于非战士学员(P<0.05).新训过程中,男性非战士学员训练伤发生率明显高于战士学员(46.7％vs.9.1％,P<0.05),女性非战士学员和战士学员训练伤发生率分别为50.0％和38.7％.lo-gistic回归分析显示,人体成分综合评分是军事训练伤的潜在保护因素[OR=0.966,95％CI(0.934,0.999),P=0.044].结论 人体成分综合评分可作为预防新兵军事训练伤分组训练的依据,人体成分综合评分低的学员是军事训练伤的高发人群,应在军事训练中重点防护.

Systemic application of glucocorticoids is an essential anti-inflammatory and immune-modulating therapy for severe inflammatory or autoimmunity conditions. However, its long-term effects on articular cartilage of patients' health need to be further investigated. In this study, we studied the effects of dexamethasone (Dex) on the homeostasis of articular cartilage and the progress of destabilization of medial meniscus (DMM)-induced osteoarthritis (OA) in adult mice. Long-term administration of Dex aggravates the proteoglycan loss of articular cartilage and drastically accelerates cartilage degeneration under surgically induced OA conditions. In addition, Dex increases calcium content in calcified cartilage layer of mice and the samples from OA patients with a history of long-term Dex treatment. Moreover, long term usage of Dex results in decrease subchondral bone mass and bone density. Further studies showed that Dex leads to calcification of extracellular matrix of chondrocytes partially through activation of AKT, as well as promotes apoptosis of chondrocytes in calcified cartilage layer. Besides, Dex weakens the stress-response autophagy with the passage of time. Taken together, our data indicate that long-term application of Dex may predispose patients to OA and or even accelerate the OA disease progression development of OA patients.

Acquired heterotopic ossification (HO) is the extraskeletal bone formation after trauma. Various mesenchymal progenitors are reported to participate in ectopic bone formation. Here we induce acquired HO in mice by Achilles tenotomy and observe that conditional knockout (cKO) of fibroblast growth factor receptor 3 ( FGFR3 ) in Col2 + cells promote acquired HO development. Lineage tracing studies reveal that Col2 + cells adopt fate of lymphatic endothelial cells (LECs) instead of chondrocytes or osteoblasts during HO development. FGFR3 cKO in Prox1 + LECs causes even more aggravated HO formation. We further demonstrate that FGFR3 deficiency in LECs leads to decreased local lymphatic formation in a BMPR1a-pSmad1/5-dependent manner, which exacerbates inflammatory levels in the repaired tendon. Local administration of FGF9 in Matrigel inhibits heterotopic bone formation, which is dependent on FGFR3 expression in LECs. Here we uncover Col2 + lineage cells as an origin of lymphatic endothelium, which regulates local inflammatory microenvironment after trauma and thus influences HO development via FGFR3-BMPR1a pathway. Activation of FGFR3 in LECs may be a therapeutic strategy to inhibit acquired HO formation via increasing local lymphangiogenesis.

Apert syndrome (AS) is characterized by synostosis of coronal sutures, midfacial hypoplasia,abnormity of brain, syndactyly of hands and feet. Majority of AS is caused by gain-of-function mutation of fibro‐blast growth factor receptor 2 (FGFR2). To date, the treatment of AS is surgical correction for the deformed skull.The reconstruction of sutures is often executed several times, because of constant premature of sutures. Some dis‐eased tissues, such as brain, are difficult to treat with surgery. CRISPR/Cas9 gene editing technology exhibits pow‐erful prospect in the treatment of human genetic diseases. In this study, small guiding RNA (gRNA) specificallytargeting the Fgfr2 gene was screened and lentivirus mediated Cas9/gRNA was employed to treat mice (Fg‐fr2+/P253R) that mimicking human Apert syndrome in primary calvarial cells, calvarial explants or calvarial bone. Incultured primary calvarial cells, Cas9/gRNA reduced the phosphorylation of ERK1/2 and P38, and resultantly inhibited osteoblastic differentiation and matrix mineralization. Besides, Cas9/gRNA attenuated the premature closure ofcoronal suture and the decreased calvarial bone volume calvarial explants and AS mice. This study provides exper‐imental basis of gene therapy for Apert syndrome, and is prospective to provide new strategies for the treatment ofskeletal genetic diseases.

Osteoarthritis (OA) is the most common joint disease. The surface of joint cartilage is a defensive and first affected structure of articular cartilage (AC) during the pathogenesis of OA. Alk5 signaling is critical for maintaining AC homeostasis, however, the role and underlying mechanism for the involvement of Alk5 signaling in the phenotypes of articular cartilage stem cells (ACSCs) at the surface of AC is still unclear. The role of Alk5 in OA development was explored using an ACSCs‐specific Alk5 ‐deficient (cKO) mouse model. Alterations in cartilage structure were evaluated histologically. Senescence was detected by SA‐β‐gal, while reactive oxygen species (ROS), MitoTracker, and LysoTracker staining were used to detect changes related to senescence. In addition, mice were injected intra‐articularly with ganciclovir to limit the detrimental roles of senescent cells (SnCs). Alk5 cKO mice showed a decreased number of the slow‐cell cycle cells and less lubricant secretion at the surface accompanied with drastically accelerated cartilage degeneration under ageing and surgically induced OA conditions. Further studies showed that Alk5 deficient ACSCs exhibited senescence‐like manifestations including decreased proliferation and differentiation, more SA‐β‐gal‐positive cells and ROS production, as well as significantly swollen mitochondria and lysosome breakdown. We further found that local limitation of the detrimental roles of SnCs can attenuate the development of posttraumatic OA. Taken together, our findings suggest that Alk5 signaling acts as an important regulator of the SnCs in the superficial layer during AC maintenance and OA initiation.

Apert综合征(Apert Syndrome,AS)是一类常染色体显性遗传疾病,主要表现为颅缝早闭、中面部发育不良、并指(趾)、智力发育障碍等,多由FGFR2分子功能增强型点突变引起.目前,此疾病主要靠手术矫形来恢复功能,其中大脑等病变部位手术难度大,难以实施,且通常需要多次手术.CRISPR/Cas9基因编辑技术在人类遗传病治疗中具有巨大潜力.本研究筛选到靶向FGFR2基因的gRNA,与Cas9经慢病毒包装后作用于Apert小鼠(FGFR2+/P253R)的原代颅骨细胞、体外培养的颅骨以及活体小鼠颅骨中,可敲低FGFR2的表达,改善Apert原代颅骨细胞的分化程度.CRISPR/Cas9处理体外培养的颅骨及注射至Apert小鼠头颅,颅骨冠状缝早闭状态有效缓解,异常降低的颅骨骨量、骨密度等也显著改善,表明CRISPR/Cas9基因编辑可缓解Apert小鼠头颅异常.本研究为Apert综合征的基因治疗提供了实验依据,有望为其它骨骼遗传病治疗提供新的策略与借鉴.

Exosomes participate in many physiological and pathological processes by regulating cell–cell communication, which are involved in numerous diseases, including osteoarthritis (OA). Exosomes are detectable in the human articular cavity and were observed to change with OA progression. Several joint cells, including chondrocytes, synovial fibroblasts, osteoblasts, and tenocytes, can produce and secrete exosomes that influence the biological effects of targeted cells. In addition, exosomes from stem cells can protect the OA joint from damage by promoting cartilage repair, inhibiting synovitis, and mediating subchondral bone remodeling. This review summarizes the roles and therapeutic potential of exosomes in OA and discusses the perspectives and challenges related to exosome-based treatment for OA patients in the future.

Congenital scoliosis (CS) is a complex genetic disorder characterized by vertebral malformations. The precise etiology of CS is not fully defined. Here, we identify that mutation in dual serine/threonine and tyrosine protein kinase (dstyk) lead to CS-like vertebral malformations in zebrafish. We demonstrate that the scoliosis in dstyk mutants is related to the wavy and malformed notochord sheath formation and abnormal axial skeleton segmentation due to dysregulated biogenesis of notochord vacuoles and notochord function. Further studies show that DSTYK is located in late endosomal/lysosomal compartments and is involved in the lysosome biogenesis in mammalian cells. Dstyk knockdown inhibits notochord vacuole and lysosome biogenesis through mTORC1-dependent repression of TFEB nuclear translocation. Inhibition of mTORC1 activity can rescue the defect in notochord vacuole biogenesis and scoliosis in dstyk mutants. Together, our findings reveal a key role of DSTYK in notochord vacuole biogenesis, notochord morphogenesis and spine development through mTORC1/TFEB pathway.

CATSHL syndrome, characterized by camptodactyly, tall stature and hearing loss, is caused by loss-of-function mutations of fibroblast growth factor receptors 3 (FGFR3) gene. Most manifestations of patients with CATSHL syndrome start to develop in the embryonic stage, such as skeletal overgrowth, craniofacial abnormalities, however, the pathogenesis of these phenotypes especially the early maldevelopment remains incompletely understood. Furthermore, there are no effective therapeutic targets for this skeleton dysplasia. Methods: We generated fgfr3 knockout zebrafish by CRISPR/Cas9 technology to study the developmental mechanisms and therapeutic targets of CATSHL syndrome. Several zebrafish transgenic lines labeling osteoblasts and chondrocytes, and live Alizarin red staining were used to analyze the dynamical skeleton development in fgfr3 mutants. Western blotting, whole mount in situ hybridization, Edu labeling based cell proliferation assay and Wnt/β-catenin signaling antagonist were used to explore the potential mechanisms and therapeutic targets. Results: We found that fgfr3 mutant zebrafish, staring from early development stage, showed craniofacial bone malformation with microcephaly and delayed closure of cranial sutures, chondroma-like lesion and abnormal development of auditory sensory organs, partially resembling the clinical manifestations of patients with CATSHL syndrome. Further studies showed that fgfr3 regulates the patterning and shaping of pharyngeal arches and the timely ossification of craniofacial skeleton. The abnormal development of pharyngeal arch cartilage is related to the augmented hypertrophy and disordered arrangement of chondrocytes, while decreased proliferation, differentiation and mineralization of osteoblasts may be involved in the delayed maturation of skull bones. Furthermore, we revealed that deficiency of fgfr3 leads to enhanced IHH signaling and up-regulated canonical Wnt/β-catenin signaling, and pharmacological inhibition of Wnt/β-catenin could partially alleviate the phenotypes of fgfr3 mutants. Conclusions: Our study further reveals some novel phenotypes and underlying developmental mechanism of CATSHL syndrome, which deepens our understanding of the pathogenesis of CATSHL and the role of fgfr3 in skeleton development. Our findings provide evidence that modulation of Wnt/β-catenin activity could be a potential therapy for CATSHL syndrome and related skeleton diseases.

Objective To explore the effect of dexamethasone (Dex) infusion on articular cartilage and the underlying mechanisms in vitro and in vivo . Methods Destabilization of medial meniscus (DMM)-induced OA mouse model was used in this study. The mice with Dex treatment were sacrificed and then the knee joint samples were obtained for pathological analysis. Mouse primary chondrocytes were isolated and cultured in the presence or absence of Dex, which were used for calcification analysis and western blot assay. Results Dex accelerated the loss of articular cartilage matrix in mice, while it aggravated the damage of cartilage in DMM-induced OA model at the late stage. The calcium content in calcified cartilage layer in the joints from Dex treated OA mice was significantly higher than that from control mice. Dex treatment enhanced mineralization of articular cartilage matrix and leaded to massive apoptosis of chondrocytes in OA model. In addition, Dex caused autophagy of chondrocytes in the early stage, which was decreased at the late stage of Dex treatment. Moreover, we found that the effect of Dex on the mineralization of articular cartilage matrix in mice was related to AKT activation. Conclusions Continuous infusion of Dex can enhance the calcification of cartilage via AKT activation and increase chondrocyte apoptosis through inhibiting autophagy, which aggravates the damage of articular cartilage and accelerates the progression of OA in vivo.

Synovitis plays an important role in the pathogenesis of arthritis, which is closely related to the joint swell and pain of patients. The purpose of this study was to investigate the anti-inflammatory effects of pulsed electromagnetic fields (PEMF) on synovitis and its underlying mechanisms. Destabilization of the medial meniscus (DMM) model and air pouch inflammation model were established to induce synovitis in C57BL/6 mice. The mice were then treated by PEMF (pulse waveform, 1.5 mT, 75 Hz, 10% duty cycle). The synovitis scores as well as the levels of IL-1β and TNF-α suggested that PEMF reduced the severity of synovitis in vivo. Moreover, the proportion of neutrophils in the synovial-like layer was decreased, while the proportion of macrophages increased after PEMF treatment. In addition, the phagocytosis of apoptotic neutrophils by macrophages (efferocytosis) was enhanced by PEMF. Furthermore, the data from western blot assay showed that the phosphorylation of P38 was inhibited by PEMF. In conclusion, our current data show that PEMF noninvasively exhibits the anti-inflammatory effect on synovitis via upregulation of the efferocytosis in macrophages, which may be involved in the phosphorylation of P38.

Low‐intensity pulsed ultrasound (LIPUS), a noninvasive physical therapy, was recently demonstrated to be an effective treatment for osteoarthritis (OA). Vascular endothelium growth factor A (VEGFA) has been found to be upregulated in the articular cartilage, synovium and subchondral bone of OA patients, leading to cartilage degeneration, synovitis and osteophyte formation. However, the functions and mechanisms of LIPUS in regulating chondrocyte‐derived VEGFA expression are still unclear. In this study, we investigated whether LIPUS attenuated OA progression by (a) decreasing the percentage of VEGFA‐positive cells in mouse articular cartilage destabilised through medial meniscus surgery and (b) relieving interleukin‐1β‐induced VEGFA expression in mouse primary chondrocytes. However, this function was negated by a p38 mitogen‐activated protein kinase (p38 MAPK) inhibitor. In addition, we found that LIPUS ameliorated VEGFA‐mediated disorders in cartilage extracellular matrix metabolism and chondrocyte hypertrophy during OA development. In conclusion, our data indicate a novel effect of LIPUS in regulating the expression of osteoarthritic chondrocyte‐derived VEGFA through the suppression of p38 MAPK activity.