The connection between tendons and bones is called the tendon bone connection. With the continuous improvement of national sports awareness, excessive exercises and the related intensity are prone to damage the tendon bone connection. Tendon bone healing is a complex repair and healing process involving multiple factors, and good tendon bone healing is a prerequisite for its physiological function. The complexity of tendon bone structure also poses great challenges to the repair of tendon bone injuries. In recent years, researches have found that stem cells, growth factors, macrophages, and other factors are closely related to the healing process of tendon bone injuries, among which macrophages play an important role in the healing process. The authors reviewed relevant research literature in recent years and summarized the role of macrophages in tendon bone healing, in order to provide new ideas and directions for treatment strategies to promote tendon bone healing.
Humans ; Macrophages/metabolism* ; Wound Healing ; Animals ; Tendons/physiology* ; Bone and Bones/injuries* ; Tendon Injuries

OBJECTIVE: To investigate whether the Runx2 gene can induce the differentiation of human amniotic mesenchymal stem cells (hAMSCs) to ligament fibroblasts in vitro and promote the tendon-bone healing in rabbits. METHODS: hAMSCs were isolated from the placentas voluntarily donated from healthy parturients and passaged, and then identified by flow cytometric identification. Adenoviral vectors carrying Runx2 gene (Ad-Runx2) and empty vector adenovirus (Ad-NC) were constructed and viral titer assay; then, the 3rd generation hAMSCs were transfected with Ad-Runx2 (Ad-Runx2 group) or Ad-NC (Ad-NC group). The real-time fluorescence quantitative PCR and Western blot were used to detect Runx2 gene and protein expression to verify the effectiveness of Ad-Runx2 transfection of hAMSCs; and at 3 and 7 days after transfection, real-time fluorescence quantitative PCR was further used to detect the expressions of ligament fibroblast-related genes [vascular endothelial growth factor (VEGF), collagen type Ⅰ, Fibronectin, and Tenascin-C]. The hAMSCs were used as a blank control group. The hAMSCs, hAMSCs transfected with Ad-NC, and hAMSCs were mixed with Matrigel according to the ratio of 1 : 1 and 1 : 2 to construct the cell-scaffold compound. Cell proliferation was detected by cell counting kit 8 (CCK-8) assay, and the corresponding cell-scaffold compound with better proliferation were taken for subsequent animal experiments. Twelve New Zealand white rabbits were randomly divided into 4 groups of sham operation group (Sham group), anterior cruciate ligament reconstruction group (ACLR group), anterior cruciate ligament reconstruction+hAMSCs transfected with Ad-NC-scaffold compound group (Ad-NC group), and anterior cruciate ligament reconstruction+hAMSCs transfected with Ad-Runx2-scaffold compound group (Ad-Runx2 group), with 3 rabbits in each group. After preparing the ACL reconstruction model, the Ad-NC group and the Ad-Runx2 group injected the optimal hAMSCs-Matrigel compunds into the bone channel correspondingly. The samples were taken for gross, histological (HE staining and sirius red staining), and immunofluorescence staining observation at 1 month after operation to evaluate the inflammatory cell infiltration as well as collagen and Tenascin-C content in the ligament tissues. RESULTS: Flow cytometric identification of the isolated cells conformed to the phenotypic characteristics of MSCs. The Runx2 gene was successfully transfected into hAMSCs. Compared with the Ad-NC group, the relative expressions of VEGF and collagen type Ⅰ genes in the Ad-Runx2 group significantly increased at 3 and 7 days after transfection ( P<0.05), Fibronectin significantly increased at 3 days ( P<0.05), and Tenascin-C significantly increased at 3 days and decreased at 7 days ( P<0.05). CCK-8 detection showed that there was no significant difference ( P>0.05) in the cell proliferation between groups and between different time points after mixed culture of two ratios. So the cell-scaffold compound constructed in the ratio of 1∶1 was selected for subsequent experiments. Animal experiments showed that at 1 month after operation, the continuity of the grafted tendon was complete in all groups; HE staining showed that the tissue repair in the Ad-Runx2 group was better and there were fewer inflammatory cells when compared with the ACLR group and the Ad-NC group; sirius red staining and immunofluorescence staining showed that the Ad-Runx2 group had more collagen typeⅠ and Ⅲ fibers, tending to form a normal ACL structure. However, the fluorescence intensity of Tenascin-C protein was weakening when compared to the ACLR and Ad-NC groups. CONCLUSION Runx2 gene transfection of hAMSCs induces directed differentiation to ligament fibroblasts and promotes tendon-bone healing in reconstructed anterior cruciate ligament in rabbits.
Pregnancy ; Female ; Humans ; Rabbits ; Animals ; Vascular Endothelial Growth Factor A/metabolism* ; Fibronectins/metabolism* ; Collagen Type I/genetics* ; Tenascin/metabolism* ; Collagen/metabolism* ; Anterior Cruciate Ligament/surgery* ; Mesenchymal Stem Cells ; Tendons/metabolism* ; Fibroblasts/metabolism*

OBJECTIVETo explore function and related molecular mechanism of osteopractic total flavone (OTF) on tendon healing in rats.

METHODSTen male rats aged for 8 weeks were collected and weighted from 180 to 220 g. Tendon stem cells were cultivated, the third tendon stem cells were used for experiment. OTP treated with 0, 0.1, 1, 10 ng/ml were added into tendon stem cells, and expression change of ALP, Runx2, OCN, VEGF, P-S6, P-4E/BP1 were detected after 14 days. Forty male rats aged for 8 weeks (weighted 180 to 220 g) were established extra-articular tendon-bone transplanting healing model, and divided into experimental group and control group. Experimental group were treated with OTF(100 mg·kg⁻¹·d⁻¹), while control group was treated by normal saline with the same volume. Tendon-bone healing degree were detected by biomechanical testing at 3 and 6 weeks after surgery, histological detection were applied to detect tendon-bone healing and number of new vessles.

RESULTSAfter treated by OTP, ALP staining and active index detection showed there were statistical differences among 0, 0.1, 1, 10 ng/ml group. After 14 days' cultivation, western blotting results showed mTOR downstream marker protein P-S6 protein expression were gradually increased with increase of density of OTP, expression of P-4E/BP1 was reduced, while expression of Runx2, OCN, VEGF were increased. Biological detection results showed that there was no significant difference in mechanical strength between experimental group(0.78±0.05) N/mm and control group (0.51±0.02) N/mm at 3 weeks after surgery, while mechanical strength in experimental group (1.36±0.09) N/mm was higher than control group (1.01±0.08) N/mm at 6 weeks after surgery. Histological results showed maturity of tendon-bone surface cell were higher at 3 and 6 weeks in experimental group, sharpey fiber growth more density, calcification extent of mesenchyme was high, and new bone, vessels were increased.

CONCLUSIONSOTF could promote osteogenic differentiation of tendon stem cells through mTOR signaling in vitro, and stimulate tendon-bone healing in bone tunnel and enhance connection quality between tendon and bone.

Animals ; Biomechanical Phenomena ; Bone Transplantation ; Cell Differentiation ; Cells, Cultured ; Flavones ; pharmacology ; Male ; Osteogenesis ; Rats ; Stem Cells ; cytology ; TOR Serine-Threonine Kinases ; metabolism ; Tendons ; cytology ; transplantation ; Wound Healing

Numerous musculoskeletal disorders are caused by thickened ligament, tendon stiffness, or fibrosis of joint capsule. Relaxin, a peptide hormone, can exert collagenolytic effect on ligamentous and fibrotic tissues. We hypothesized that local injection of relaxin could be used to treat entrapment neuropathy and adhesive capsulitis. Because hormonal effect depends on the receptor of the hormone on the target cell, it is important to confirm the presence of such hormonal receptor at the target tissue before the hormone therapy is initiated. The aim of this study was to determine whether there were relaxin receptors in the ligament, tendon, and joint capsular tissues of rats and to identify the distribution of relaxin receptors in these tissues. Transverse carpal ligaments (TCLs), inguinal ligaments, anterior cruciate ligaments (ACLs), Achilles tendons, and shoulder joint capsules were obtained from male Wistar rats. Western blot analysis was used to identify relaxin receptor isoforms RXFP1 and RXFP2. The distribution of relaxin receptors was determined by immunohistochemical staining. The RXFP1 isoform was found in all tissues examined. The RXFP2 isoform was present in all tissues but the TCLs. Its expression in ACLs tissues was relatively weak compared to that in other tissues. Our results revealed that RXFP1 and RXFP2 were distributed in distinctly different patterns according to the type of tissue (vascular endothelial cells, fibroblast-like cells) they were identified.
Animals ; Blotting, Western ; *Gene Expression Regulation ; Immunohistochemistry ; Ligaments/*metabolism ; Male ; Rats ; Rats, Wistar ; Receptors, G-Protein-Coupled/*genetics/metabolism ; Receptors, Peptide/*genetics/metabolism ; Shoulder Joint/*metabolism ; Tendons/*metabolism

PURPOSE: This study was designed to measure time-dependent changes in muscle excursion and collagen content after tenotomy, and to analyze the correlation between muscle excursion and collagen content in a rabbit model. MATERIALS AND METHODS: Twenty-four rabbits underwent tenotomy of the second extensor digitorum longus (EDL) muscles on the right legs and were randomly assigned to three groups based on the period of time after tenotomy (2, 4, and 6 weeks). The second EDL muscles on left legs were used as controls. At each time after tenotomy, passive muscle excursion and collagen content, determined by hydroxyproline content, were measured bilaterally, and the ratio of each value to the normal one was used. RESULTS: The mean ratio of muscle excursion after tenotomy to the value of the control decreased in a time-dependent fashion: 92.5% at 2 weeks, 78.6% at 4 weeks, and 55.1% at 6 weeks. The mean ratio of hydroxyproline content in muscle to the value of the control increased in a time-dependent fashion: 119.5% at 2 weeks, 157.3% at 4 weeks, and 166.6% at 6 weeks. There was a significant negative correlation between the ratio of hydroxyproline content in muscle after tenotomy to the control values and the ratio of muscle excursion after tenotomy to the control values (r=-0.602, p=0.002). CONCLUSION: The decrease in muscle excursion seems to correlate with the increase in collagen content in the muscle in a time-dependent fashion following tenotomy.
Animals ; Collagen/*metabolism ; Hydroxyproline/metabolism ; Muscle, Skeletal/*metabolism ; Rabbits ; Tendon Injuries/*metabolism ; Tendons ; Tenotomy ; Time Factors

Xanthomas are local collections of lipid-laden macrophages and collagen, which are usually associated with impaired lipoprotein metabolism. Xanthomas occur frequently in the skin, subcutis, or tendon, and occasionally in the plantar fascia. Small numbers of xanthomas have been surgically confirmed in the plantar fascia and their sonographic appearance has not been described in the literature. We present sonographic findings of a pathologically proven plantar fascia xanthoma, which was initially mistaken as plantar fibromatosis.
Collagen ; Fascia ; Fibroma* ; Foot ; Lipoproteins ; Macrophages ; Metabolism ; Skin ; Tendons ; Ultrasonography ; Xanthomatosis*

OBJECTIVEAnalyze the immunophenotype of the different cells in the various subtypes of giant cell tumor of tendon sheath (GCTS) and investigate the value of clusterin in pathological diagnosis and histogenesis of giant cell tumor of tendon sheath.

METHODSA total of 104 cases of GCTS from the surgical pathology files of Shanghai Jiaotong university affiliated the sixth people's hospital were identified. Immunohistochemistry (IHC) for clusterin, desmin, CD163, CD68, p63, p53, Ki-67 and CD35 was performed on all cases, using EnVision technique.

RESULTSAll cases of GCTS were researched, including 44 cases of localized type (L-GCTS), 32 cases of diffused type (D-GCTS), 26 cases of pigmented villonodular synovitis (PVNS) and 2 cases of malignant type. There was a slight female predominance in all these subtypes, and the male to female ratio was about 38:66. L-GCTS usually occured within the small joints (90.9%, 40/44), while D-GCTS, PVNS and M-GCTS commonly occured within the large weight-bearing joints [68.8% (22/32), 100% (26/26) and 2/2 respectively]. Of 74 cases with follow-up, the recurrence rates of L-GCTS, D-GCTS, PVNS and M-GCTS respectively were 30.3% (10/33), 30.4% (7/23), 18.8% (3/16) and 2/2. The different subtypes of GCTS had the same cell components, including the large synovial-like mononuclear cells, the small histiocytoid cells, foamy histiocytes cells, inflammatory cells, fibroblasts and the osteoclast-like multinucleated giant cells. There were obvious differences among immunophenotype of the various cell components in GCTS: the large synovial-like mononuclear cells were strong positive for clusterin, partly positive for desmin and Ki-67, and negative for CD163. The small histiocytoid cells were strong positive for CD163 but negative for clusterin and desmin. The osteoclast-like multinucleated giant cells were strong positive for CD68 but negative for clusterin, CD163 and desmin. Normal synoviocytes were strong positive for clusterin, partly positive for desmin. The number of the large synovial-like mononuclear cells that were positive for clusterin in D-GCTS were more than that in L-GCTS (P < 0.01) and PVNS (P < 0.05).

CONCLUSIONSGCTS was synovial tumors, not belonged to the category of fibrohistiocytic lesions. The true tumor cells may be the large synovial-like mononuclear cells, and the number of the cells in the D-GCTS was obviously more than that in L-GCTS and PVNS. This may be the reason that the biological behavior of D-GCTS was more aggressive, destructive and recurrent. Clusterin was an useful marker in pathological differential diagnosis of GCTS.

Adult ; Antigens, CD ; metabolism ; Antigens, Differentiation, Myelomonocytic ; metabolism ; Biomarkers, Tumor ; metabolism ; Clusterin ; metabolism ; Desmin ; metabolism ; Female ; Follow-Up Studies ; Giant Cell Tumors ; metabolism ; pathology ; Humans ; Male ; Middle Aged ; Neoplasm Recurrence, Local ; Receptors, Cell Surface ; metabolism ; Sex Factors ; Soft Tissue Neoplasms ; metabolism ; pathology ; Tendons

Calcium-Binding Proteins ; metabolism ; Diagnosis, Differential ; Female ; Fibroma ; metabolism ; pathology ; surgery ; Humans ; Inclusion Bodies ; pathology ; Infant ; Microfilament Proteins ; metabolism ; Skin Neoplasms ; metabolism ; pathology ; surgery ; Soft Tissue Neoplasms ; pathology ; Tendons ; pathology ; Toes ; Vimentin ; metabolism

OBJECTIVETo optimize the culture media by adding the growth factors required to maintain tenocytes survival and promote their differentiation without fetal bovine serum (FBS) supplementation, in order for the approach to be used for any future tendon tissue engineering.

METHODSThe human tenocytes were cultured in α-MEM media by adding FBS at various concentrations and supplementing both insulin-like growth factor 1 (IGF-1) and transforming growth factor β-3 (TGFβ-3). A number of growth factors were selected that could support tenocytes expansion at reduced differentiated state with the minimum FBS. By employing fractional factorial design, different treatment groups went through AlamarBlue(TM) tests to evaluate the cell number growth whilst collagen quantification by real time RT-PCR technique and tenocyte differentiation were also studied.

RESULTSThe tenocytes cultured for 14 days with 0% FBS, 50 ng/ml IGF-1 and 10 ng/ml TGFβ-3 maintained survival over 14 days, the Cell count were 6228.68 ± 43.87. They were higher than the other experimental groups, but less than 10% FBS control group (13 576.74 ± 286.75, t = 41.29, P < 0.05). The tenocytes cultured in the treated group also showed enhanced collagen synthesis ((0.322 ± 0.003) ng, t = 4.13 - 5.93, P < 0.05).

CONCLUSIONThese findings have shown for the first time that human tenocytes could be maintained survival for a long period of time in the culture media without FBS, having this approach a suitable one for tendon tissue engineering.

Cell Differentiation ; drug effects ; Cell Survival ; drug effects ; Cells, Cultured ; Collagen ; biosynthesis ; Culture Media ; pharmacology ; Humans ; Insulin-Like Growth Factor I ; pharmacology ; Tendons ; cytology ; drug effects ; metabolism ; Transforming Growth Factor beta3 ; pharmacology

Adult ; Diagnosis, Differential ; Female ; Fibroma ; metabolism ; pathology ; Fingers ; Giant Cell Tumors ; metabolism ; pathology ; Humans ; Mucin-1 ; metabolism ; Nerve Sheath Neoplasms ; metabolism ; pathology ; surgery ; Neurilemmoma ; metabolism ; pathology ; Sclerosis ; metabolism ; pathology ; Soft Tissue Neoplasms ; metabolism ; pathology ; surgery ; Tendons ; Young Adult