The role of TGF-beta3 in cartilage development and osteoarthritis

Articular cartilage serves as a low-friction,load-bearing tissue without the support with blood vessels,lymphatics and nerves,making its repair a big challenge.Transforming growth factor-beta 3(TGF-β3),a vital member of the highly conserved TGF-βsuperfamily,plays a versatile role in cartilage physiology and pathology.TGF-β3 influences the whole life cycle of chondrocytes and mediates a series of cellular responses,including cell survival,proliferation,migration,and differentiation.Since TGF-β3 is involved in maintaining the balance between chondrogenic differentiation and chondrocyte hypertrophy,its regulatory role is especially important to cartilage development.Increased TGF-β3 plays a dual role:in healthy tissues,it can facilitate chondrocyte viability,but in osteoarthritic chondrocytes,it can accelerate the progression of disease.Recently,TGF-β3 has been recognized as a potential therapeutic target for osteoarthritis(OA)owing to its protective effect,which it confers by enhancing the recruitment of autologous mesenchymal stem cells(MSCs)to damaged cartilage.However,the biological mechanism of TGF-β3 action in cartilage development and OA is not well understood.In this review,we systematically summarize recent progress in the research on TGF-β3 in cartilage physiology and pathology,providing up-to-date strategies for cartilage repair and preventive treatment.

Inhibition of fibroblast activation protein ameliorates cartilage matrix degradation and osteoarthritis progression

Fibroblast activation protein(Fap)is a serine protease that degrades denatured type I collagen,α2-antiplasmin and FGF21.Fap is highly expressed in bone marrow stromal cells and functions as an osteogenic suppressor and can be inhibited by the bone growth factor Osteolectin(Oln).Fap is also expressed in synovial fibroblasts and positively correlated with the severity of rheumatoid arthritis(RA).However,whether Fap plays a critical role in osteoarthritis(OA)remains poorly understood.Here,we found that Fap is significantly elevated in osteoarthritic synovium,while the genetic deletion or pharmacological inhibition of Fap significantly ameliorated posttraumatic OA in mice.Mechanistically,we found that Fap degrades denatured type II collagen(Col II)and Mmp13-cleaved native Col II.Intra-articular injection of r Fap significantly accelerated Col II degradation and OA progression.In contrast,Oln is expressed in the superficial layer of articular cartilage and is significantly downregulated in OA.Genetic deletion of Oln significantly exacerbated OA progression,which was partially rescued by Fap deletion or inhibition.Intra-articular injection of r Oln significantly ameliorated OA progression.Taken together,these findings identify Fap as a critical pathogenic factor in OA that could be targeted by both synthetic and endogenous inhibitors to ameliorate articular cartilage degradation.

基于Y-shaped路网的早高峰拼车定价策略

针对交通资源配置有限导致的早高峰通勤拥堵问题,借鉴共享经济理论,引入拼车出行概念,充分考虑通勤者出行方式和Y-shaped路网特点,建立了基于通勤者出行效益的拼车定价模型.模型结合费用补偿机制,讨论了以平台利润最大化和系统负效用最小化为目标的拼车定价策略,并给出了定价策略有效的阈值条件.研究结果表明,当通勤者都参与到拼车服务中时,拼车平台利润和交通系统负效用在其相应拼车定价策略下均能达到最优值,并且以交通系统负效用最小化为目标的拼车定价策略能消除Y-shaped路网中瓶颈处的交通拥堵.

Divergent chondro/osteogenic transduction laws of fibrocartilage stem cell drive temporomandibular joint osteoarthritis in growing mice

The anterior disc displacement(ADD)leads to temporomandibular joint osteoarthritis(TMJOA)and mandibular growth retardation in adolescents.To investigate the potential functional role of fibrocartilage stem cells(FCSCs)during the process,a surgical ADDTMJOA mouse model was established.From 1 week after model generation,ADD mice exhibited aggravated mandibular growth retardation with osteoarthritis(OA)-like joint cartilage degeneration,manifesting with impaired chondrogenic differentiation and loss of subchondral bone homeostasis.Lineage tracing using Gli1^(-)CreER^(+);Tm^(fl/-)mice and Sox9-CreER^(+);Tm^(fl/-)mice showed that ADD interfered with the chondrogenic capacity of Gli1+FCSCs as well as osteogenic differentiation of Sox9+lineage,mainly in the middle zone of TMJ cartilage.Then,a surgically induced disc reposition(DR)mouse model was generated.The inhibited FCSCs capacity was significantly alleviated by DR treatment in ADD mice.And both the ADD mice and adolescent ADD patients had significantly relieved OA phenotype and improved condylar growth after DR treatment.In conclusion,ADD-TMJOA leads to impaired chondrogenic progenitor capacity and osteogenesis differentiation of FCSCs lineage,resulting in cartilage degeneration and loss of subchondral bone homeostasis,finally causing TMJ growth retardation.DR at an early stage could significantly alleviate cartilage degeneration and restore TMJ cartilage growth potential.

Cartilage Wear in Healthy and Osteoarthritis Joints

This study is designed to determine whether the outermost layer of articular cartilage is deficient in Osteoarthritis (OA). Phospholipids present in healthy and osteoarthritis (OA) synovial fluid show significant differences in their concentration. While examining the surface properties of OA joints, we found that OA PLs molecules cannot support lubrication, and increased friction was observed. Our lubrication mechanism was based on a surface active phospholipids (SAPL) multibilayer which in OA condition was deactivated and removed from the cartilage surface under OA conditions. Cartilage wettability study clearly demonstrated a significant decrease in hydrophobicity, the contact angle, θ (theta), dropping from 103° from bovine healthy cartilage to 65° in surface partially depleted and 35.1° for completely depleted surface. These results are discussed in the context that surface active phospholipid (SAPL) and lubricin, each has specific roles in a lamellar-repulsive lubrication system. However, deactivated phospholipid molecules are major indicator of cartilage wear (model) introduced in this study.

Purifi cation and identification of anti-inflammatory peptides from sturgeon (Acipenser schrenckii) cartilage

Cartilage is a nonedible byproduct with little saleable value.However,previous studies have proposed the possibility of producing peptides from cartilage with immune function modulation potential.The current study aimed to investigate the potential anti-inflammatory activity of peptides derived from sturgeon(Acipenser schrenckii)cartilage in lipopolysaccharide(LPS)-stimulated RAW264.7 macrophages.Five peptide sequences,including four novel peptides,were identified from ethanol-soluble cartilage hydrolysates.Among these five peptides,LTGP,LLLE,LLEL and VGPAGPAGP reduced the production of nitric oxide(NO)and interleukin-6(IL-6)while increasing interleukin-10(IL-10)excretion.Transcriptome analysis suggested the inhibition of activated mitogen-activated protein kinase(MAPK)and interleukin-17(IL-17)signaling pathways after LLEL intervention.MAPK,which is involved in the IL-17 signaling pathway,was further proved to be blocked by downregulating the phosphorylation of p38,extracellular-signal regulated protein kinase(ERK),and c-jun N-terminal kinase(JNK).This novel peptide offers an attractive approach to develop functional foods.

Robotic in situ bioprinting for cartilage tissue engineering

Articular cartilage damage caused by trauma or degenerative pathologies such as osteoarthritis can result in significant pain,mobility issues,and disability.Current surgical treatments have a limited capacity for efficacious cartilage repair,and long-term patient outcomes are not satisfying.Three-dimensional bioprinting has been used to fabricate biochemical and biophysical environments that aim to recapitulate the native microenvironment and promote tissue regeneration.However,conventional in vitro bioprinting has limitations due to the challenges associated with the fabrication and implantation of bioprinted constructs and their integration with the native cartilage tissue.In situ bioprinting is a novel strategy to directly deliver bioinks to the desired anatomical site and has the potential to overcome major shortcomings associated with conventional bioprinting.In this review,we focus on the new frontier of robotic-assisted in situ bioprinting surgical systems for cartilage regeneration.We outline existing clinical approaches and the utilization of robotic-assisted surgical systems.Handheld and robotic-assisted in situ bioprinting techniques including minimally invasive and non-invasive approaches are defined and presented.Finally,we discuss the challenges and potential future perspectives of in situ bioprinting for cartilage applications.

3D printing of personalized polylactic acid scaffold laden with GelMA/autologous auricle cartilage to promote ear reconstruction

At present,the clinical reconstruction of the auricle usually adopts the strategy of taking autologous costal cartilage.This method has great trauma to patients,poor plasticity and inaccurate shaping.Three-dimensional(3D)printing technology has made a great breakthrough in the clinical application of orthopedic implants.This study explored the combination of 3D printing and tissue engineering to precisely reconstruct the auricle.First,a polylactic acid(PLA)polymer scaffold with a precisely customized patient appearance was fabricated,and then auricle cartilage fragments were loaded into the 3D-printed porous PLA scaffold to promote auricle reconstruction.In vitro,gelatin methacrylamide(GelMA)hydrogels loaded with different sizes of rabbit ear cartilage fragments were studied to assess the regenerative activity of various autologous cartilage fragments.In vivo,rat ear cartilage fragments were placed in an accurately designed porous PLA polymer ear scaffold to promote auricle reconstruction.The results indicated that the chondrocytes in the cartilage fragments could maintain the morphological phenotype in vitro.After three months of implantation observation,it was conducive to promoting the subsequent regeneration of cartilage in vivo.The autologous cartilage fragments combined with 3D printing technology show promising potential in auricle reconstruction.

杂交鲟(Sturgeon cartilage)软骨中硫酸软骨素的提取方法及分析鉴定

采用稀碱浸提、蛋白酶水解与三氯乙酸沉淀相结合脱蛋白的工艺,对杂交鲟软骨提取琉酸软骨素的方法进行了较系统的研究。综合考察各种影响因素,设计了正交试验对提取工艺参数进行了优化,并对产品的质量指标进行了检验。结果表明,最佳提取工艺参数为:碱提取时料液比为1:2.0,碱浓度为4%,碱提温度为40℃;胰蛋白酶的酶解温度为55℃,酶量为2%,酶解时间为10h,制备的硫酸软骨素为白色粉末,得率为28.9%,纯度为92.3%,蛋白质含量为2.59%,各项质量指标完全符合标准要求。与目前已报道的其他软骨素制备工艺相比较,该方法具有工艺简便,提取率高,产品纯度高的特点。光谱分析法结构鉴定结果表明它是一种软骨素肽,其主要成分为硫酸软骨素C。

Use of bone morphogenetic proteins in mesenchymal stemcell stimulation of cartilage and bone repair

The extracellular matrix-associated bone morphogenetic proteins(BMPs) govern a plethora of biological processes. The BMPs are members of the transforming growth factor-β protein superfamily, and they actively participate to kidney development, digit and limb formation, angiogenesis, tissue fibrosis and tumor development. Since their discovery, they have attracted attention for their fascinating perspectives in the regenerative medicine and tissue engineering fields. BMPs have been employed in many preclinical and clinical studies exploring their chondrogenic or osteoinductive potential in several animal model defects and in human diseases. During years of research in particular two BMPs, BMP2 and BMP7 have gained the podium for their use in the treatment of various cartilage and bone defects. In particular they have been recently approved for employment in non-union fractures as adjunct therapies. On the other hand, thanks to their potentialities in biomedical applications, there is a growing interest in studying the biology of mesenchymal stem cell(MSC), the rules underneath their differentiation abilities, and to test their true abilities in tissue engineering. In fact, the specific differentiation of MSCs into targeted celltype lineages for transplantation is a primary goal of the regenerative medicine. This review provides an overview on the current knowledge of BMP roles and signaling in MSC biology and differentiation capacities. In particular the article focuses on the potential clinical use of BMPs and MSCs concomitantly, in cartilage and bone tissue repair.

Mesenchymal stem cells as a potent cell source for articular cartilage regeneration

Since articular cartilage possesses only a weak capac-ity for repair, its regeneration potential is considered one of the most important challenges for orthopedic surgeons. The treatment options, such as marrow stimulation techniques, fail to induce a repair tissue with the same functional and mechanical properties of native hyaline cartilage. Osteochondral transplantation is considered an effective treatment option but is as-sociated with some disadvantages, including donor-site morbidity, tissue supply limitation, unsuitable mechani-cal properties and thickness of the obtained tissue. Although autologous chondrocyte implantation results in reasonable repair, it requires a two-step surgical pro-cedure. Moreover, chondrocytes expanded in culture gradually undergo dedifferentiation, so lose morpho-logical features and specialized functions. In the search for alternative cells, scientists have found mesenchymal stem cells(MSCs) to be an appropriate cellular mate-rial for articular cartilage repair. These cells were origi-nally isolated from bone marrow samples and further investigations have revealed the presence of the cells in many other tissues. Furthermore, chondrogenic dif-ferentiation is an inherent property of MSCs noticedat the time of the cell discovery. MSCs are known to exhibit homing potential to the damaged site at which they differentiate into the tissue cells or secrete a wide spectrum of bioactive factors with regenerative proper-ties. Moreover, these cells possess a considerable im-munomodulatory potential that make them the general donor for therapeutic applications. All of these topics will be discussed in this review.

Benefits of Ilizarov automated bone distraction for nerves and articular cartilage in experimental leg lengthening

AIM To determine peculiarities of tissue responses to manual and automated Ilizarov bone distraction in nerves and articular cartilage.METHODS Twenty-nine dogs were divided in two experimental groups: Group M-leg lengthening with manual distraction(1 mm/d in 4 steps), Group A-automated distraction(1 mm/d in 60 steps) and intact group. Animals were euthanized at the end of distraction, at 30 th day of fixation in apparatus and 30 d after the fixator removal. M-responses in gastrocnemius and tibialis anterior muscles were recorded, numerical histology of peronealand tibialis nerves and knee cartilage semi-thin sections, scanning electron microscopy and X-ray electron probe microanalysis were performed.RESULTS Better restoration of M-response amplitudes in leg muscles was noted in A-group. Fibrosis of epineurium with adipocytes loss in peroneal nerve, subperineurial edema and fibrosis of endoneurium in some fascicles of both nerves were noted only in M-group, shares of nerve fibers with atrophic and degenerative changes were bigger in M-group than in A-group. At the end of experiment morphometric parameters of nerve fibers in peroneal nerve were comparable with intact nerve only in A-group. Quantitative parameters of articular cartilage(thickness, volumetric densities of chondrocytes, percentages of isogenic clusters and empty cellular lacunas, contents of sulfur and calcium) were badly changed in M-group and less changed in A-group.CONCLUSION Automated Ilizarov distraction is more safe method of orthopedic leg lengthening than manual distraction in points of nervous fibers survival and articular cartilage arthrotic changes.

Injectable hydrogels for cartilage and bone tissue engineering

Tissue engineering has become a promising strategy for repairing damaged cartilage and bone tissue. Among the scaffolds for tissue-engineering applications, injectable hydrogels have demonstrated great potential for use as three-dimensional cell culture scaffolds in cartilage and bone tissue engineering, owing to their high water content, similarity to the natural extracellular matrix(ECM), porous framework for cell transplantation and proliferation, minimal invasive properties, and ability to match irregular defects. In this review, we describe the selection of appropriate biomaterials and fabrication methods to prepare novel injectable hydrogels for cartilage and bone tissue engineering. In addition, the biology of cartilage and the bony ECM is also summarized. Finally, future perspectives for injectable hydrogels in cartilage and bone tissue engineering are discussed.

T1ρ/T2 mapping and histopathology of degenerative cartilage in advanced knee osteoarthritis

AIM To investigate whether normal thickness cartilage in osteoarthritic knees demonstrate depletion of proteoglycan or collagen content compared to healthy knees.METHODS Magnetic resonance(MR) images were acquired from5 subjects scheduled for total knee arthroplasty(TKA)(mean age 70 years) and 20 young healthy control subjects without knee pain(mean age 28.9 years). MR images of T1ρ mapping, T2 mapping, and fat suppressed proton-density weighted sequences were obtained.Following TKA each condyle was divided into 4 parts(distal medial, posterior medial, distal lateral, posterior lateral) for cartilage analysis. Twenty specimens(bone and cartilage blocks) were examined. For each joint,the degree and extent of cartilage destruction was determined using the Osteoarthritis Research Society International cartilage histopathology assessment system.In magnetic resonance imaging(MRI) analysis, 2 readers performed cartilage segmentation for T1ρ/T2 values and cartilage thickness measurement.RESULTS Eleven areas in MRI including normal or near normal cartilage thickness were selected. The corresponding histopathological sections demonstrated mild to moderate osteoarthritis(OA). There was no significant difference in cartilage thickness in MRI between control and advanced OA samples [medial distal condyle, P = 0.461;medial posterior condyle(MPC), P = 0.352; lateral distal condyle, P = 0.654; lateral posterior condyle, P = 0.550],suggesting arthritic specimens were morphologically similar to normal or early staged degenerative cartilage.Cartilage T2 and T1ρ values from the MPC were significantly higher among the patients with advanced OA(P= 0.043). For remaining condylar samples there was no statistical difference in T2 and T1ρ values between cases and controls but there was a trend towards higher values in advanced OA patients. CONCLUSION Though cartilage is morphologically normal or near normal, degenerative changes exist in advanced OA patients. These changes can be detected with T2 and T1ρ MRI techniques.

Use of chondral fragments for one stage cartilage repair: A systematic review

AIM: To investigate the state of the art regarding Cartilage Autograft Implantation System(CAIS) or Particulated Juvenile Allograft Cartilage(PJAC).METHODS: The authors searched the English literature regarding CAIS and PJAC. The search strategy was:(particulated cartilage) OR autologous cartilage fragments. All basic science articles were included. Clinical articles with less than 10 patients treated and less than 6 mo of follow-up were excluded. With these criteria, a total of 17 articles were available for the present review. RESULTS: PJAC and CAIS are relatively novel techniques for cartilage repair. Good basic science evidence was described to support the concept. Although the preliminary clinical reports show encouraging results, clinical data are still limited, especially for CAIS. The indications for both techniques need to be precisely defined(age of the patients, size of the lesion, and involvement of the subchondral bone), together with other debated issues. CONCLUSION: In conclusion, the authors can state that encouraging preliminary results are available for both techniques. However, further studies are necessary to precisely determine the indications, surgical techniques, and long term outcomes for PJAC and CAIS.

Mesenchymal stem cells for cartilage regeneration in osteoarthritis

Osteoarthritis(OA) is a slowly progressive disease where cartilage of the synovial joint degenerates. It is most common in the elderly where patients experience pain and reduce physical activity. In combination with lack of conventional treatment, patients are often left with no other choices than arthroplasty. Over the last years, multipotent stromal cells have been used in efforts to treat OA. Mesenchymal stem/progenitor cells(MSCs) are stromal cells that can differentiate into bone, fat, and cartilage cells. They reside within bone marrow and fat. MSCs can also be found in synovial joints where they affect the progression of OA. They can be isolated and proliferated in an incubator before being applied in clinical trials. When it comes to treatment, emphasis has hitherto been on autologous MSCs, but allogenic cells from healthy donors are emerging as another source of the cells. The first adaptations of MSCs revolved in the use of cellrich matrix, delivered as invasive surgical procedure, which resulted in production of hyaline cartilage and fibrocartilage. However, the demand for less invasive delivery of cells has prompted the use of direct intraarticular injections, wherein a large amount of suspended cells are implanted in the cartilage defect.

A new method for computing the uniaxial modulus of articular cartilages using modified inhomogeneous triphasic model

It is well known that subtle changes in structure and tissue composition of articular cartilage can lead to its degeneration. The present paper puts forward a modified layered inhomogeneous triphasic model with four parameters based on the inhomogeneous triphasic model proposed by Narmoneva et al. Incorporating a piecewise fitting optimization criterion, the new model was used to obtain the uniaxial modulus Ha, and predict swelling pattern for the articular cartilage based on ultrasound-measured swelling strain data. The results show that the new method can be used to provide more accurate estimation on the uniaxial modulus than the inhomogeneous triphasic model with three parameters and the homogeneous mode, and predict effectively the swell- ing strains of highly nonuniform distribution of degenerated articular cartilages. This study can provide supplementary information for exploring mechanical and material properties of the cartilage, and thus be helpful for the diagnosis of osteoarthritis-related diseases.

New perspectives for articular cartilage repair treatment through tissue engineering: A contemporary review

In this paper review we describe benefits and disadvantages of the established methods of cartilage regeneration that seem to have a better long-term effectiveness.We illustrated the anatomical aspect of the knee joint cartilage, the current state of cartilage tissue engineering, through mesenchymal stem cells and biomaterials,and in conclusion we provide a short overview on the rehabilitation after articular cartilage repair procedures.Adult articular cartilage has low capacity to repair itself,and thus even minor injuries may lead to progressive damage and osteoarthritic joint degeneration, result-ing in significant pain and disability. Numerous efforts have been made to develop tissue-engineered grafts or patches to repair focal chondral and osteochondral defects, and to date several researchers aim to implement clinical application of cell-based therapies for cartilage repair. A literature review was conducted on PubM ed, Scopus and Google Scholar using appropriate keywords, examining the current literature on the wellknown tissue engineering methods for the treatment of knee osteoarthritis.

Cartilage repair techniques of the talus: An update

Symptomatic chondral or osteochondral defects of the talus reduce the quality of life of many patients.Although their pathomechanism is well understood,it is well known that different aetiologic factors play a role in their origin.Additionally,it is well recognised that the talar articular cartilage strongly differs from that in the knee.Despite this fact,many recommendations for the management of talar cartilage defects are based on approaches that were developed for the knee.Conservative treatment seems to work best in paediatric and adolescent patients with osteochondritis dissecans.However,depending on the size of the lesions,surgical approaches are necessary to treat many of these defects.Bone marrow stimulation techniques may achieve good results in small lesions.Large lesions may be treated by open procedures such as osteochondral autograft transfer or allograft transplantation.Autologous chondrocyte transplantation,as a restorative procedure,is well investigated in the knee and has been applied in the talus with increasing popularity and promising results but the evidence to date is poor.The goals of the current article are to summarise the different options for treating chondral and osteochondral defects of the talus and review the available literature.

Association between serum cartilage oligomeric matrix protein and coronary artery calcification in maintenance hemodialysis patients

Background Coronary artery calcification(CAC)is common in end-stage renal disease(ESRD)patients,and the extent of CAC is closely related to cardiovascular outcomes in ESRD patients.Cartilage oligomeric matrix protein(COMP),as a component of the vascular matrix,has been found to be an inhibitor of arterial calcification in basic studies.However,there is no clinical research on the correlation between COMP and CAC in maintenance hemodialysis(MHD)patients.The aim of this study was to explore the relationship between serum COMP levels and CAC and cardiovascular events in MHD patients.Methods Serum COMP levels were compared between 54 MHD patients and 66 healthy people.MHD patients were then divided into three groups according to the tertiles of the concentration of COMP level and were followed up for major adverse cardiac events(MACEs),which were defined as a combined end point of new onset angina pectoris,nonfatal myocardial infarction,heart failure,coronary artery revascularization,hospitalization due to angina pectoris and all-cause deaths.The CAC score was calculated based on computed tomography scans.Results The serum COMP level in MHD patients was significantly higher than that in the general population[984.23(248.43-1902.61)ng/mL vs.219.01(97.26-821.92)ng/mL,P<0.01].Serum COMP levels were positively correlated with CAC(r=0.313,P=0.021)and serum parathyroid hormone in MHD patients(r=0.359,P<0.01).Linear regression suggested that after adjusting for age,fasting blood glucose(Glu)and glycosylated hemoglobin(HbAlc),CAC score was an independent predictor in the final model for COMP level(β=0.424,t=3.130,P<0.01).The receiver operating characteristic(ROC)curve showed that COMP≥994 mg/mL had 68.0%sensitivity and 72.4%specificity for the prediction of severe CAC[area under the curve(AUC):0.674,P=0.030,95%CI:0.526-0.882].After a median follow-up of 16 months(8-24 months),there was no difference in the incidence rate of MACEs between the upper,middle and lower serum COMP groups.Conclusions Our study found that MHD patients have higher levels of circulating COMP than controls.The serum COMP level is positively correlated with CAC score and could be used as a biomarker of severe CAC in MHD patients.However,there is no obvious correlation between serum COMP levels and the incidence of cardiovascular events.