Rabbit Knee Osteoarthritis Research Articles

Exploring the mechanism of tetramethylpyrazine in the treatment of osteoarthritis based on network pharmacology.

Osteoarthritis (OA) is the most common joint disease, which mainly damages articular cartilage and involves the whole joint tissue. It has the characteristics of long course, repeated symptoms and high disability rate, and the incidence trend is gradually increasing. Tetramethylpyrazine (TMP) is the main alkaloid active substance in Ligusticum wallichii, a traditional Chinese medicine, which has the effect of promoting blood circulation and dredging collaterals, and has a good effect on the treatment of early OA, but its molecular mechanism has not been fully clarified so far. Based on network pharmacology, molecular docking simulation and animal experiments, this study explored the target and molecular mechanism of TMP in the treatment of OA. We used PubChem, SwissTargetPrediction, and PharmMapper databases to predict the molecular structure and potential targets of TMP. GeneCards and DisGeNET databases were used to predict the relevant targets of OA. Apply UniProt database to convert targets into unified gene names, and proofread and remove duplicate gene names. The intersection targets of TMP and OA obtained on venny2.1.0 website were submitted to the STRING database to construct a PPI network. CytoScape 3.8.2 software was used to analyze the PPI network and obtain the sub-network modules and 10 key targets. The intersection targets of TMP and OA were analyzed by Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) enrichment using DAVID 6.8 database. The intersecting targets of TMP and OA, the biological process of GO enrichment, and KEGG signaling pathway were imported into Cytoscape 3.8.2 software to construct the TMP-target-pathway network diagram. Use molecular docking technology to simulate the interaction between TMP molecules and key targets, and predict the binding mode and binding ability. Animal models of rabbit knee osteoarthritis were prepared, and magnetic resonance imager (MRI) and fluorescence quantitative PCR (RT-qPCR) were used to observe the effect of TMP in treating OA as well as the expression of key target genes. 585 potential targets of TMP, 3,857 potential targets of OA, and 49 intersecting targets of TMP and OA were obtained. The top 10 key target genes were obtained, in order of ranking: ALB, ESR1, IL10, CAT, F2, MPO, C3, CYP3A4, CYP2C9, ANXA1. GO and KEGG analysis implied that the key targets might act on OA by affecting endothelial cell permeability, peri-articular microcirculatory status, NETs production, activation of complement system and coagulation pathway, regulation of immune function of macrophages and T cells, and substance metabolism pathway in vivo, etc. The molecular mechanism might involve the formation of neutrophil extracellular trap, regulation of the actin cytoskeleton, complement and coagulation cascades, and T cell receptor signaling pathways, etc. Molecular docking simulations showed that the binding energy of IL10 and ANXA1 to TMP was greater than -5Kal/mol, but the other key target proteins showed better binding to TMP, and the binding energy was less than -5kcal/mol. Animal experiments showed that TMP had a significant therapeutic effect on OA. The TMP group had significantly reduced knee joint effusion and bone marrow damage compared to the OA group (p < 0.05). The qRT-PCR results showed that compared with the OA group, the mRNA expression of ESR1, CAT, C3, CYP3A4, CYP2C9, and ANXA1 in the TMP group increased (p < 0.05), while there was no significant difference in mRNA expression of ALB, IL-10, F2, MPO, etc. (p > 0.05). TMP is effective in the treatment of OA, with multi-target and multi-pathway interactions. ESR1, CAT, C3, CYP3A4, CYP2C9, and ANXA1 may be potential targets for TMP treatment of OA. The molecular mechanism mainly involves the formation of neutrophil extracellular trap, regulation of the actin cytoskeleton, complement and coagulation cascades, and T cell receptor signaling pathways, etc.

Establishment of rabbit knee osteoarthritis model by simple anterior cruciate ligament disruption

The rabbit knee osteoarthritis(KOA) model was established by simple anterior cruciate ligament disruption. The selected 40 adult white rabbits were randomly divided into two groups, blank group with 6 rabbits and model group with 34 rabbits. The rabbits in model group were given the disruption of anterior cruciate ligament of right knee joint. In the fourth, eighth and the twelfth weeks of modeling, different degrees of degenerative changes have been observed on the rabbits articular cartilages from both macroscopic and microscopic aspects. At 4, 8 and 12 weeks after modeling, the articular cartilage of the rabbits in the model group showed degenerative changes in different degrees. At 8 and 12 weeks, the typical pathological manifestations of KOA in the middle and late stages were found in the infrapatellar fat pad and synovium, respectively. There were no changes in articular cartilage, infrapatellar fat pad and synovial membrane in the blank group at the same time. There were significant differences in the gross score between the model group and the blank group at 4 weeks [(1.300±0.674) vs 0.000], 8 weeks [(2.400±0.516) vs 0.000] and 12 weeks [(3.583±0.668) vs 0.000] (P<0.05), the histopathological scores were significantly different, at 4 weeks [(2.900±0.567) vs 0.000], 8 weeks [(7.500±1.178) vs (0.500±0.707)], 12 weeks[(11.833±1.337) vs (1.500±0.707)], (P<0.05). The establishment of rabbit knee arthritis model by simply cutting the anterior cruciate ligament is simple and feasible, with good stability, high success rate, small trauma, short modeling cycle and less changes in animal physiological structure. The rabbit knee arthritis model established by simply cutting the anterior cruciate ligament has good modeling effect on different stages and grades of knee osteoarthritis, and the postoperative infection and trauma can be controlled, which can meet the test requirements.

Promotion and Mechanism of Acupotomy on Chondrocyte Autophagy in Knee Osteoarthritis Rabbits.

To explore the effect of acupotomy intervention on autophagy of chondrocytes in rabbits with knee osteoarthritis (KOA), and to determine the possible mechanisms of acupotomy to alleviate cartilage degeneration. The modified Videman method was used to construct a KOA rabbit model. After modeling, 40 rabbits were randomly divided into 4 groups by a random number table: control; KOA (model); KOA + acupotomy (acupotomy), and KOA + sham acupotomy (sham), 10 in each group. After a 3-week treatment course, the knee joint activity was determined by the modified Lequesne MG index. Hematoxylin-eosin staining staining was used to examine the morphological changes of chondrocytes. Autophagy of chondrocytes was observed by transmission electron microscopy. The surface morphology of cartilage tissue was observed by scanning electron microscope. The mRNA and protein levels of AMP kinase/mammalian target of rapamycin/Unc-51 (AMPK/mTOR/ULK1) signal pathway key proteins, autophagy-related factor Beclin-1 and microtubule-associated protein 1A/1B light chain 3 (LC3) in rabbit knee cartilage were assessed by real-time fluorescence quantitative polymerase chain reaction and Western blot, respectively. The modified Lequesne MG score of acupotomy group was significantly lower than that of model group (P<0.05). Pathological results showed that chondrocyte autophagy decreased and cartilage surface was rough in the model group, which recovered after acupotomy treatment. The mRNA expressions of AMPK, ULK1, Beclin-1 and the protein levels of p-AMPK, p-ULK1, Beclin-1, and LC3 II/LC3 I were decreased in the model group, while the mRNA and protein expressions of mTOR were increased (P<0.01). However, acupotomy treatment reversed these abnormal changes (P<0.05). Acupotomy could effectively up-regulate the expressions of AMPK, ULK1 and Beclin1, reduce the expression of mTOR, promote autophagy, and alleviate joint degeneration. Acupotomy is a promising complementary and alternative therapy for KOA.

Intra-articular administration of extra-virgin olive oil in degenerative osteoarthritis

BackgroundWe aimed to analyze the outcomes of intraarticular extra virgin olive oil (EVOO) injection on mechanically induced rabbit knee osteoarthritis (OA) by studying the morphological, histological, and radiological findings.MethodsThe study was conducted on 32 New Zealand White rabbits. The randomly numbered subjects were divided into two main groups. The rabbits numbered 1 to 16 were selected to be the group to receive EVOO, and the remaining were selected into a control group. Both groups were separated into two subgroups for short-term (five weeks) and long-term (10 weeks) follow-up. Anterior cruciate ligament transection was applied on the left knees of all the rabbits via medial parapatellar arthrotomy to simulate knee instability. Immediately after the surgical procedure, 0.2 cc of EVOO was injected into the knee joint of rabbits numbered 1–16, and the control group received 0.2 cc of sterile saline. On the 14th day, long-term group subjects were administered another dose of 0.2 cc EVOO intraarticularly.ResultsThe gross morphological scores of the control group subjects were significantly different from the EVOO group for both short-term (p = 0,055) and long-term (p = 0,041) scores. In parallel, the MRI results of the EVOO subjects were significantly different from the control group for both short-term and long-term follow-up assessment scores (p = 0.017, p = 0.014, respectively). The Mankin scoring results showed that there were statistically significant differences between the EVOO and control group in the comparison of both total scores (p = 0.001 for short-term and p = 0.004 for long-term) and subgroup scoring, including macroscopic appearance, chondrocyte cell number, staining, and Tidemark integrity in both short-term (p = 0.005, p = 0.028, p = 0.001, p = 0.005, respectively) and long-term assessments (p = 0.002, p = 0.014, p < 0.001, p = 0. 200, respectively).ConclusionsWe have observed promising outcomes of intra-articular application of extra virgin olive oil in the treatment of acute degenerative osteoarthritis in rabbit knees. Due to its potential cartilage restorative and regenerative effects, EVOO, when administered intra-articularly, may be a promising agent to consider for further research in the treatment of OA.

Acupotomy alleviates knee osteoarthritis in rabbit by regulating chondrocyte mitophagy Pink1-Parkin pathway.

To investigate the effect of acupotomy, on mitophagy and the Pink1-Parkin pathway in chondrocytes from rabbits with knee osteoarthritis (KOA). A KOA model was established via the modified Videman method. Rabbits were randomly divided into a control group (CON), KOA group and KOA + acupotomy group (Acu). Rabbits in the acupotomy group were subjected to acupotomy for 4 weeks after model establishment. The behavior of the rabbits before and after intervention was recorded. Cartilage degeneration was evaluated by optical microscopy and fluorescence microscopy. The level of mitophagy was evaluated by transmission electron microscopy, immunofluorescence and enzyme-linked immunosorbent assay (ELISA). The expression of phosphatase and tensin homolog (PTEN)-induced kinase 1 (Pink1)-Parkin mitophagy pathway components was evaluated by immunofluorescence, Western blotting and real-time polymerase chain reaction. In rabbits with KOA, joint pain, mobility disorders and cartilage degeneration were observed, the Mankin score was increased, collagen type Ⅱ (Col-Ⅱ) expression was significantly decreased, mitophagy was inhibited, mitochondrial function was impaired, and factors associated with the Pink1-Parkin pathway were inhibited. Acupotomy regulated the expression of Pink1-Parkin pathway-related proteins, the mitophagy-related protein microtubule-associated protein-1 light chain-3, the translocase of the outer membrane, and the inner mitochondrial membrane 23; increased the colocalization of mitochondria and autophagosomes; promoted the removal of damaged mitochondria; restored mitochondrial adenosine-triphosphate (ATP) production; and alleviated cartilage degeneration in rabbits with KOA. Acupotomy played a role in alleviating KOA in rabbits by activating mitophagy in chondrocytes via the regulation of proteins that are related to the Pink1-Parkin pathway.

Acupotomy ameliorates knee osteoarthritis-related collagen deposition and fibrosis in rabbit skeletal muscle through the TGF-β/Smad pathway

ObjectiveTo investigate the effects of acupotomy on skeletal muscle fibrosis and collagen deposition in a rabbit knee osteoarthritis (KOA) model. MethodsRabbits (n = 18) were randomly divided into control, KOA, and KOA + acupotomy (Apo) groups (n = 6). The rabbits in the KOA and Apo groups were modeled using the modified Videman's method for 6 weeks. After modeling, the Apo group was subjected to acupotomy once a week for 3 weeks on the vastus medialis, vastus lateralis, rectus femoris, biceps femoris, and anserine bursa tendons around the knee. The behavior of all animals was recorded, rectus femoris tissue was obtained, and histomorphological changes were observed using Masson staining and transmission electron microscopy. The expression of transforming growth factor-β1 (TGF-β1), Smad 3, Smad 7, fibrillar collagen types I (Col-I) and III (Col-III) was detected using Western blot and real-time polymerase chain reaction (RT-PCR). ResultsHistological analysis revealed that acupotomy improved the microstructure and reduced the collagen volume fraction of rectus femoris, compared with the KOA group (P = .034). Acupotomy inhibited abnormal collagen deposition by modulating the expression of fibrosis-related proteins and mRNA, thus preventing skeletal muscle fibrosis. Western blot and RT-PCR analysis revealed that in the Apo group, Col-I, and Col-III protein levels were significantly lower than those in the KOA group (both P < .01), same as Col-I and Col-III mRNA levels (P = .0031; P = .0046). Compared with the KOA group, the protein levels of TGF-β1 and Smad 3 were significantly reduced (both P < .01), as were the mRNA levels of TGF-β1 and Smad 3 (P = .0007; P = .0011). Conversely, the levels of protein and mRNA of Smad 7 were significantly higher than that in the KOA group (P < .01; P = .0271). ConclusionAcupotomy could alleviate skeletal muscle fibrosis and delay KOA progress by inhibiting collagen deposition through the TGF-β/Smad pathway in the skeletal muscle of KOA rabbits.

Effect of umbilical cord blood-mononuclear cells on knee osteoarthritis in rabbits

BackgroundTo investigate the effect and underlying mechanism of umbilical cord blood-mononuclear cells (UCB-MNCs) in treating knee osteoarthritis (KOA) in rabbits.MethodsA rabbit KOA model was prepared by anterior cruciate ligament transection (ACLT). Fifty New Zealand white rabbits were randomly divided into the control group, model group, sodium hyaluronate (SH) group, platelet-rich plasma (PRP) group and UCB-MNC group. Knee injections were performed once a week for five consecutive weeks. The gross view of the knee joint, morphology of knee cartilage and structural changes in the knee joint were observed on CT scans, and graded by the Lequesne MG behavioral score and the Mankin score. TNF-α and IL-1β levels in the synovial fluid of the knee were measured by the enzyme-linked immunosorbent assay (ELISA). Expression levels of MMP-13 and COL-II in the knee cartilage were detected by Western blotting and qRT-PCR.ResultsThe Lequesne MG behavioral score and the Mankin score were significantly higher in the model group than those in the control group (P < 0.05). Rabbits in the SH, PRP and UCB-MNC groups had sequentially lower scores than those in the model group. Imaging features of KOA were more pronounced in the model group than in the remaining groups. CB-MNC significantly relieved KOA, compared to SH and PRP. Significantly higher levels of TNF-α and IL-1β in the synovial fluid of the knee, and up-regulated MMP-13 and down-regulated COL-II in the knee cartilage were detected in the model group than in the control group. These changes were significantly reversed by the treatment with SH, PRP and UCB-MNCs, especially UCB-MNCs.ConclusionInjections of UCB-MNCs into knees protect the articular cartilage and hinder the progression of KOA in rabbits by improving the local microenvironment at knee joints.

Mechanism of acupotomy on chondrocyte ferroptosis in rabbits with knee osteoarthritis based on HSPA5/GPX4 signaling pathway

To observe the effect of acupotomy on heat shock protein A family member 5 (HSPA5)/glutathione peroxidase 4 (GPX4) signaling pathway in the chondrocytes of the rabbits with knee osteoarthritis (KOA) and explore the mechanism of acupotomy on chondrocyte ferroptosis in KOA. Twenty-seven New Zealand rabbits were randomly divided into a normal group, a model group and an acupotomy group, with 9 rabbits in each group. The left hind limb was fixed by the modified Videman method for 6 weeks to establish KOA model. After modeling, acupotomy was given in the acupotomy group, once a week and for consecutive 3 weeks. Using Lequesne MG score, the local symptoms, physical signs and functions of knee joint were evaluated. With HE staining and saffrane-solid green staining adopted, the morphology of chondrocytes and cartilage tissue was observed. Under transmission electron microscope, the mitochondrial structure of chondrocytes was observed. The iron content of cartilage tissue was detected by iron ion kit. The mitochondrial membrane potential (Δψm) and the reactive oxygen species (ROS) level in cartilage tissue were determined by flow cytometry, and the mitochondrial damage rate was calculated. The mRNA expression of HSPA5, GPX4, type Ⅱ collagen α1 chain (COL2A1), matrix metalloproteinases (MMP) 3 and MMP13 was detected by the real-time quantitative PCR; and the protein expression of HSPA5, GPX4, type Ⅱ collagen (COL-Ⅱ), MMP3 and MMP13 was detected by Western blot. The mean flourscence intensity of HSPA5 and GPX4 in cartilage tissue was determined by immunofluorescence. Before intervention, compared with the normal group, the Lequesne MG scores were increased in the model group and the acupotomy group (P<0.01). After intervention, the Lequesne MG score in the acupotomy group was decreased when compared with that in the model group. In comparison with that in the normal group, the number of chondrocytes was reduced and the cells were disarranged; the layers of cartilage structure were unclear, the tide lines disordered and blurred; the mitochondria were wrinkled and the mitochondrial crista decreased or even disappeared in the model group. Compared with the model group, the number of chondrocytes was increased, the layers of cartilage structure were clear, the tide lines recovered, the number of mitochondria elevated, with normal structure and more crista in the acupotomy group. The iron content of cartilage tissue was increased (P<0.01), the Δψm of chondrocytes was declined, the mitochondrial damage rate was increased (P<0.01), the average fluorescence intensity of ROS was increased (P<0.01); the mRNA and corresponding protein expression of HSPA5, GPX4 and COL2A1 was decreased (P<0.01), the mRNA and protein expression of MMP3 and MMP13 was increased (P<0.01) and the average fluorescence intensity of HSPA5, GPX4 was decreased (P<0.01) in the model group when compared with those in the normal group. Compared with the model group, the iron content in cartilage tissue was reduced (P<0.01), the Δψm of chondrocytes was increased, the mitochondrial damage rate was decreased (P<0.01), and the average fluorescence intensity of ROS was decreased (P<0.01); the mRNA and corresponding protein expression of HSPA5, GPX4 and COL2A1 was higher (P<0.01), and the mRNA and protein expression of MMP3 and MMP13 was lower, and the average fluorescence intensity of HSPA5, GPX4 was increased (P<0.01) in the acupotomy group. Acupotomy can alleviate cartilage injury of KOA rabbits, and its mechanism may be related to the regulation of HSPA5/GPX4 signaling pathway to maintain iron homeostasis in articular cartilage, thus inhibiting chondrocyte ferroptosis and relieving extracellular matrix degradation.

Quantitative evaluation of warm acupuncture-moxibustion in improvement of cartilage damage in rabbits with early knee osteoarthritis based on MR T2 mapping.

To observe the application value of MR T2 mapping for evaluating the effect of warm acupuncture-moxibustion on articular cartilage degeneration, and to observe the relationship between T2 value and expression of matrix metalloproteinases (MMP)-1 and MMP-13 of chondrocytes in rabbits with early knee osteoarthritis (KOA). Thirty male New Zealand rabbits were randomly divided into blank control, KOA model and warm acupuncture-moxibustion groups, with 10 rabbits in each group. The early KOA model was established by right hind limb tubular plaster extension fixation method for 2 weeks. The rabbits of the warm acupuncture-moxibustion group received warm acupuncture-moxibustion stimulation at "Heding"(EX-LE2), "Neixiyan"(EX-LE4), "Waixiyan" (EX-LE5) and"Zusanli"(ST36) on the right hind limb for 15 min, once a day for 2 weeks. After intervention, MR T2 mapping of the right knee joint was performed in each group. The H.E. staining was used to evaluate the histopathological changes of cartilage, followed by giving a score according to the standards of Mankin scoring. The TUNEL method was used to analyze the apoptosis state of chondrocytes, and the positive expressions of MMP-1 and MMP-13 in the articular cartilage were detected by immunohistochemical staining. Compared with the blank control group, the Mankin score, chondrocyte apoptosis index, T2 value and the positive expressions of MMP-1 and MMP-13 in the cartilage tissue were significantly increased in the model group (P<0.01). Compared with the model group, the Mankin score, chondrocyte apoptosis index, T2 value and the positive expressions of MMP-1 and MMP-13 in the cartilage tissue were markedly decreased in the warm acupuncture-moxibustion group (P<0.01). The T2 value was positively correlated with the expression levels of MMP-1 and MMP-13 (P<0.01). H.E. staining showed disordered arrangement of chondrocytes and thinner cartilage layer in the model group, and a clear and relative ordered arrangement of chondrocyte in the warm acupuncture-moxibustion group. Warm acupuncture-moxibustion can reduce the T2 value of articular cartilage in early KOA rabbits, which is positively correlated with the decreased expression of MMP-1 and MMP-13 in the extracellular matrix of cartilage. The MR T2 mapping has certain value in evaluating the effect of warm acupuncture-moxibustion on KOA rabbits with early cartilage degeneration.

Acupotomy ameliorates subchondral bone absorption and mechanical properties in rabbits with knee osteoarthritis by regulating bone morphogenetic protein 2-Smad1 pathway.

To investigate the effects of acupotomy on the subchondral bone absorption and mechanical properties in rabbits with knee osteoarthritis (KOA). The rabbits were divided into blank control, model, acupotomy and electroacupuncture (EA) groups, with 12 rabbits in each. Modified Videman's method was used to prepare KOA model. The acupotomy and EA group were given indicated intervention for 3 weeks. The behavior of rabbits in each group was recorded. Subsequently, cartilage-subchondral bone units were obtained and morphological changes were observed by optical microscope and micro computed tomography. Compression test was used to detect the mechanical properties of subchondral bone, Western blot and real-time polymerase chain reaction (RT-PCR) were applied to detect the expression of bone morphogenetic protein 2-Smad1 (BMP2-Smad1) pathway in subchondral bone. Compared with the control group, rabbits in the KOA group showed lameness, knee pain, and cartilage degradation; the subchondral bone showed active resorption, the mechanical properties decreased significantly and the BMP2-Smad1 pathway downregulated significantly. Both acupotomy and EA intervention could increase the thickness of trabecular bone (Tb. Th), the bone volume fraction (BV/TV) and the thickness of subchondral bone plate, reduce the separation of trabecular bone (Tb. Sp), improve the maximum load and elastic modulus of subchondral bone, and effectively delay cartilage degeneration in KOA rabbits. This process may be achieved through upregulation the related proteins of BMP2-Smad1 pathway. The maximum load and elastic modulus of subchondral bone in the acupotomy group were slightly better than those in the EA group. Acupotomy could effectively protect cartilage by inhibiting abnormal bone resorption and improving mechanical properties of subchondral bone thorough the related proteins of BMP2-Smad1 pathway in KOA rabbits.

Electroacupuncture Exerts Chondroprotective Effect in Knee Osteoarthritis of Rabbits Through the Mitophagy Pathway.

Mitochondrial dysfunction of chondrocytes has become an area of focus in Knee Osteoarthritis (KOA) in recent years. Activation of mitophagy could promote the survival of chondrocytes and alleviate cartilage degeneration. The aim of this study was to explore whether mitophagy was involved in the cartilage protection of KOA rabbits after electroacupuncture (EA) intervention. The rabbits were divided into 3 groups, Control group, KOA group, EA group, with 6 rabbits in each group. KOA model rabbits were established by modified Videman's extended immobilization method for 6 weeks and randomly divided into KOA group and EA group. The rabbits in EA group were treated every other day for 3 weeks. The degree of cartilage degeneration was detected by Safranine O-Fast Green staining and immunofluorescence. The morphological changes of chondrocytes mitochondria were detected by transmission electron microscope. ATP concentration in cartilage was measured by ATP Assay Kit. The changes of Pink1-Parkin signal pathway were detected by immunofluorescence, Western blot, and Real-time PCR. The morphology showed that EA could reduce the degeneration of KOA cartilage and increase the distribution of collagen II. We also found that EA could activate mitophagy in KOA rabbit chondrocytes to remove damaged mitochondria and restore mitochondrial homeostasis, which was manifested as increasing the expression of LC3 II/I, promoting the colocalization of TOM20 and LC3B, reducing the accumulation of mitochondrial markers outer mitochondrial membrane 20 (TOM20) and inner mitochondrial membrane 23 (TIM23), and increasing ATP production in chondrocytes. This regulation might be achieved by upregulating the Pink1-Parkin signal pathway. EA may play a role in protecting KOA cartilage by activating mitophagy mediated through Pink1-Parkin pathway.

Microfracture technique combined with mesenchymal stem cells inducer represses miR-708-5p to target special at-rich sequence-binding protein 2 to drive cartilage repair and regeneration in rabbit knee osteoarthritis

Knee osteoarthritis (KOA) is a degenerative joint illness which leads to knee pain and functional limitation. In this study, we combined microfracture surgery with kartogenin (KGN), a small bioactive molecule used to promote the differentiation of mesenchymal stem cells (MSCs), and explored its impact on cartilage repair and possible latent mechanisms of action. The research offers a brand-new idea for the clinical cure of KOA. The microfracture technique in combination with KNG treatment was performed on a rabbit model of KOA. Animal behaviour was evaluated after the intra-articular injection of miR-708-5p and Special AT-rich sequence binding protein 2 (SATB2) lentiviruses. Later, the expression of the tumour necrosis factor α (TNF-α) and interleukin- 1 (IL-1), the pathology of synovial tissue and cartilage tissue, and the positive cartilage type II collagen, MMP-1, MMP-3 and TIMP-1 were detected. Finally, a luciferase assay was conducted to verify the interaction of miR-708-5p and SATB2. Our results showed that miR-708-5p was elevated in the rabbit KOA model; however, the expression of SATB2 was reduced. Meanwhile, the microfracture technology combined with MSCs inducer KGN drove cartilage repair and regeneration in rabbit KOA by repressing the miR-708-5p expression. We also found that miR-708-5p directly targeted the SATB2 mRNA to regulate its expression. Furthermore, our data urged that elevating miR-708-5p or restraining SATB2 may reverse the therapeutic effect of the microfracture technique combined with MSCs inducer on rabbit KOA. Microfracture technique combined with MSCs inducer represses miR-708-5p to target SATB2 to drive cartilage repair and regeneration in rabbit KOA. This indicates that the microfracture technique combined with MSCs inducers is supposed to be an effective latent method for osteoarthritis cure.

Effect of needle-knife on chondrocyte apoptosis of knee joint in rabbits with knee osteoarthritis based on CircSERPINE2-miR-1271-5P-ERG axis

To observe the effect of needle-knife on the chondrocyte apoptosis of knee joint in rabbits with knee osteoarthritis (KOA) based on the CircSERPINE2-miR-1271-5P-E26 specific transformation-related gene (ERG) axis, and to explore the mechanism of needle-knife for KOA. Thirty-six New Zealand white rabbits were randomly divided into a normal group, a model group, a needle-knife group and a sham needle-knife group, 9 rabbits in each group. The rabbits in the model group, the needle-knife group and the sham needle-knife group were treated with modified Videman method to prepare KOA model. After successful modeling, the rabbits in the needle-knife group were treated with needle-knife at cord adhesion and nodules near quadriceps femoris tendon and internal and external collateral ligament on the affected knee joint; the rabbits in the sham needle-knife group were treated with sham needle-knife baside the needle insertion point of the needle-knife group (needle-knife was only inserted, without any operation). The treatment was given once a week, 3 times in total. The Lequesne MG behavioral score was used to evaluate the knee joint damage in each group before and after intervention. After intervention, HE staining and transmission electron microscopy were used to observe the cartilage tissue morphology and ultrastructure of chondrocytes in the knee joint in each group; TUNEL method was used to detect the level of chondrocyte apoptosis in the knee joint; real-time fluorescence quantitative PCR was used to detect the expression of CircSERPINE2, miR-1271-5P and ERG mRNA in knee cartilage tissue in each group. After intervention, compared with the normal group, the Lequesne MG behavioral score in the model group was increased (P<0.01). Compared with the model group and the sham needle-knife group, the Lequesne MG behavioral score in the needle-knife group was decreased (P<0.01). In the model group and the sham needle-knife group, the number of chondrocytes and organelles was decreased, the cell nucleus was shrunk, mitochondria was swelling or disappeared; in the needle-knife group, the number of chondrocytes and organelles was increased, the cell nucleus was not obviously shrunk and the mitochondria was not obviously swelling. Compared with the normal group, the level of chondrocyte apoptosis in the model group was increased (P<0.01); compared with the model group and the sham needle-knife group, the level of chondrocyte apoptosis in the needle-knife group was decreased (P<0.01, P<0.05). Compared with the normal group, the expression of CircSERPINE2 and ERG mRNA in the model group was decreased (P<0.01), and the expression of miR-1271-5P mRNA was increased (P<0.01); compared with the model group and the sham needle-knife group, the expression of CircSERPINE2 and ERG mRNA in the needle-knife group was increased (P<0.01), and the expression of miR-1271-5P mRNA was decreased (P<0.01). Needle-knife could reduce the knee joint damage and chondrocyte apoptosis in KOA rabbits, which may be related to up-regulating the expression of CircSERPINE2 and ERG mRNA, and inhibiting the expression of miR-1271-5P mRNA.

Acupotomy Improves Synovial Hypoxia, Synovitis and Angiogenesis in KOA Rabbits.

Knee osteoarthritis (KOA) is a chronic inflammatory disease highly associated with intra-articular hypertension, hypoxia and angiogenesis of synovial tissue. Our previous studies showed that acupotomy could treat KOA in a variety of ways, including reducing cartilage deterioration and enhancing biomechanical qualities. However, the mechanism of hypoxia and angiogenesis induced by acupotomy in KOA synovium remains unclear. This study looked for the benign intervention of acupotomy in synovial pathology. The rabbits were divided into 3 groups, Normal group, KOA group, and KOA + Acupotomy (Apo) group, with 11 rabbits in each group. The KOA rabbit model was established by the modified Videman method with six weeks. The KOA + Apo group performed the intervention. The tendon insertion of vastus medialis, vastus lateralis, rectus femoris, biceps femoris, and anserine bursa were selected as treatment points in rabbits. Rabbits were treated once every 7 days for 3 weeks. We observed the intra-articular pressure and oxygen partial pressure (BOLD MRI). The synovial morphology was monitored by Hematoxylin-Eosin Staining (HE Staining). The expression of hypoxia-inducible transcription factor-1α (HIF-1α), vascular endothelial growth factor (VEGF), interleukin-1β (IL-1β) and tumour necrosis factor-α (TNF-α) was detected using Immunohistochemical (IHC), Western Blot and Enzyme-Linked Immunosorbent Assay (ELISA). Acupotomy reduced intra-articular hypertension and improved the synovial oxygen situation, synovial inflammatory and angiogenesis. HIF-1α, VEGF, IL-1β and TNF-α expression were downregulated by acupotomy. Acupotomy may reduce inflammation and angiogenesis in KOA rabbit by reducing abnormally elevated intra-articular pressure and improving synovial oxygen environment. The above may provide a new theoretical foundation for acupotomy treatment of KOA.

Administration of mesenchymal stem cell derivate secretome causes lower levels of Matrix Metalloproteinase-13, Aggrecanase-2, and Interleukin-1β than hyaluronic acid in rabbit knee osteoarthritis

Link of Video Abstract: https://youtu.be/XrtI29YbnTs Background: Osteoarthritis (OA) is the most common form of arthritis, which cause pain and disability that can affect the quality of life. The inflammation in OA is chronic and characterized by the infiltration of immune cells and the secretion of cytokines. Previous OA treatment used hyaluronic acid intraarticular injection, but several studies show no satisfactory clinical outcome. This study aims to determine and compare the anti-inflammatory and anti-catabolism effects of stem cell-derived secretomes versus hyaluronic acid as the gold standard for the treatment of OA. Methods: This research was conducted using an experimental randomized post-test-only control group design. According to veterinarians, the population in this study were local rabbits, aged 6-8 months, weighing &gt; 1,500 grams, and healthy. Data were analyzed using SPSS version 22.0 for Windows. Results: Twenty-two subjects were included in each treatment and control group. From the descriptive analysis, it was found that MMP-13 levels were 7.55 ± 0.23 (Treatment) (ng/mL) and 8.36 ± 1.04 (Control) (ng/mL), ADAMTS-5 levels were 0.83 ± 0.08 (Treatment) (ng/mL) and 1.14 ± 0.33 (Control) (ng/mL), and levels of IL-1β 23.0 5± 2.48 (Treatment) (ng/mL) and 26.81 ± 5.57 (Control) (ng/mL). From the inferential test, it was found that all research results were statistically significant (MMP-13= 0.81; p = 0.021; 95%CI = -1.48 – (-0.13)) (Agrekanase 2 = 0.32; p = 0.006; 95% CI = -0.53 – (-0.09)) (IL-1β = 3.76; p = 0.023; 95% CI = -7.59 – (-0.08)). Conclusion: Administration of mesenchymal stem cell-derived secretomes resulted in significantly lower levels of MMP-13, Agrekanase 2, and IL-1β compared to administration of hyaluronic acid in rabbit knee osteoarthritis

Mechanism of the inhibitory effect of acupotomy on chondrocyte apoptosis in KOA rabbits explored via proteomics 运用蛋白质组学技术探讨针刀抗KOA兔软骨细胞凋亡的作用机制

ObjectiveTo elucidate the mechanism underlying the inhibitory effect of acupotomy on chondrocyte apoptosis in rabbits with knee osteoarthritis (KOA) through screening, analysis, and verification of apoptosis-related differentially expressed proteins via proteomics. MethodsThirty New Zealand white rabbits were randomly divided into the normal, model, and acupotomy groups, with 10 rabbits in each group. The Vidman method was used to prepare KOA models in the model and acupotomy groups. In the acupotomy group, acupotomy was performed at the midpoints of the patellar ligament and medial and lateral collateral ligaments on the left knees once a week for three weeks. Rabbit articular cartilage protein was quantified in each group, and the proteins with differential expression were profiled via proteomics. The apoptosis-related proteins were further screened, and differentially expressed proteins common among the normal, model, and acupotomy groups were collected for cluster analysis. Pathological changes in chondrocytes were observed via HE staining, and chondrocyte apoptosis was observed under an electron microscope. Quantitative real-time PCR (RT-PCR) and western blot were performed to determine the mRNA and protein expression levels, respectively, of the common apoptosis-related proteins in the three groups. ResultsWestern blot and RT-PCR showed that the protein and mRNA expression levels of TXN, CAP1 and FABP3 were lower (all P < 0.05), whereas that of LTF, SCIN and IL-10 were higher (all P < 0.01) in the acupotomy group than that in the model group. ConclusionThe antiapoptotic effect of acupotomy on chondrocytes in KOA rabbits may be achieved by modulating the protein and mRNA expression of differentially expressed apoptosis-related proteins (TXN, CAP1, FABP3, LTS, SCIN, and IL-10).

Acupotomy relieves pain and improves motor function by regulating autophagy and apoptosis of cartilage in rabbits with knee osteoarthritis apoptosis

To observe the effect of acupotomy on the expression of Beclin-1, Bcl-2 and Caspase-3 in the cartilage tissue in rabbits with knee osteoarthritis (KOA), so as to explore its mechanism underling improvement of KOA. Twenty-four healthy male New Zealand rabbits were randomly and equally divided into blank control, model and acupotomy groups, with 8 rabbits in each group. By using the modified Videman's methods, the KOA model was established by left hind limb immobilization with a plaster cast for 6 weeks. The severity of KOA (knee pain, swelling and motor function) was assessed using Lequesne score, and the rabbits with a score below 4 were excluded. The acupotomy was applied to "Hedingci" (the attachment of the quadriceps tendon to the patella at the upper edge), "Binneixia" (the medial patellar supporting band attachment of medial inferior patellar margin), "Binwaixia" (the lateral patellar supporting band attachment of the lower lateral patellar margin), "Chengfeijian" (the lateral collateral ligament of the knee passes over the lateral joint space), "Weiyangci" (the medial margin of biceps femoris at the lateral end of popliteus), "Yinlingci" (the medial tibial attachment of anserinus tendon) on the left hind limb once a week for 4 weeks. One week after the last intervention, the left knee joint dysfunction severity(pain, maximum walking distance, and some activities of daily living) was evaluated by using modified Lequesne score. Histopathological changes of the cartilage were observed under light microscope after H.E. staining. The apoptosis of chondrocytes was observed after terminal deoxynucleotidyl transferase-mediated fluorescein-dUTP nick-end labeling (TUNEL) staining. The autophagolysosomes of chondrocytes were observed using transmission electron microscopy. The expression levels of Beclin-1, Bcl-2 and Caspase-3 (related factors of autophagy and apoptosis) were detected using Real-time PCR and Western blot separately. In comparison with the blank control group, the Lequesne score, apoptosis rate, expression levels of Caspase-3 mRNA and protein were significantly increased (P<0.001), and the number of autophagolysosomes, expression levels of Beclin-1 and Bcl-2 mRNAs and proteins considerably decreased (P<0.001) in the model group. Relevant to the model group, the acupotomy group had an obvious decrease in Lequesne score, rate of apoptosis, and expression levels of Caspase-3 mRNA and protein (P<0.001) and an apparent increase in the number of autophagolysosomes and expression levels of Beclin-1 and Bcl-2 mRNAs and proteins (P<0.001). Findings of H.E. staining showed severe damaged cartilage surface, with a large number of exfoliation defects, few chondrocytes on the surface and disordered arrangement of transitional cells in the model group, which was relatively milder in the acupotomy group. Acupotomy can mitigate knee-joint pain and improve functional activity in KOA rabbits, which may be associated with its functions in promoting autophagy and suppressing apoptosis by up-regulating expressions of Beclin-1 and Bcl-2 mRNAs and proteins and down-regulation of Caspase-3 mRNA and protein.

Warm acupuncture stimulation improves cartilage damage and motor function by regulating JAK2/STAT3 signaling pathway in rabbits with knee osteoarthritis

To observe the effect of warm acupuncture on the expression of Janus protein tyrosine kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) signaling pathway and inflammatory factors of articular cartilage in rabbits with knee osteoarthritis (KOA), so as to explore its underlying mechanisms in improving KOA. New Zea-land rabbits were randomly divided into blank, model, warm acupuncture and medication groups (12 rabbits in each group). The KOA model was prepared by using the right hind limb tubular plaster extension fixation method. The rabbits in the warm acupuncture group received acupuncture of "Neixiyan"(EX-LE4),"Waixiyan"(ST35),"Heding"(EX-LE2) and "Zusanli"(ST36), followed by attaching an ignited moxa-stick segment to the acupuncture-handle. The treatment was conducted for 15 min, once a week for 4 weeks. The rabbits in the medication group received gavage of diclofenac sodium solution(0.35 mg/kg), once daily for 4 weeks. The dysfunction severity state of the rabbit's knee-joint was evaluated using Lequesne scale (0-3 points), and the histopathological changes of cartilage were observed under microscope after H.E. staining and the state of distribution of chondrocytes in different layers and the extracellular matrix was assessed using Mankin score (0-6 points). The contents of serum interleukin (IL)-6, tumor necrosis factor-α (TNF-α) and matrix metalloproteinase-9 (MMP-9) were measured by using ELISA, and the expression levels of p-JAK2/JAK2, p-STAT3/STAT3 and MMP-9 in knee cartilage tissue were detected using Western blot. Compared with the blank group, the Lequesne score, Mankin score, and the contents of serum IL-6, TNF-α and MMP-9, and the ratios of p-JAK2/JAK2 and p-STAT3/STAT3, and the expression level of MMP-9 protein in knee cartilage tissue were significantly increased in the model group (P<0.01). In comparison with the model group, the Lequesne score, Mankin score, contents of serum IL-6, TNF-α and MMP-9, and the ratios of p-JAK2/JAK2 and p-STAT3/STAT3, and the expression of MMP-9 protein in knee cartilage tissue were notably decreased in both the warm acupuncture and medication groups (P<0.01,P<0.05). The levels of Lequesne score, Mankin score, contents of serum IL-6, TNF-α and MMP-9, and the ratios of p-JAK2/JAK2 and p-STAT3/STAT3 in knee cartilage tissue were significantly lower in the warm acupuncture group than in the medication group (P<0.01, P<0.05). No significant difference was found between the warm acupuncture and medication groups in the expression of MMP-9 protein (P>0.05). Outcomes of H.E. showed injury of the perichondrium of knee joint, obvious reduction of the cartilage matrix staining, cystic changes, clustered and disordered arrangement and severe pyknosis and necrosis of the surface cells with reduction of number of cells and increase of vacuoles in the model group, which was milder in both warm acupuncture and medication groups. Warm acupuncture can improve motor function and reduce cartilage injury in KOA rabbits, which may be related to its functions in inhibiting the secretion of pro-inflammatory factors and regulating JAK2/STAT3 signaling and downregulating MMP-9 expression in the cartilage tissue.

Proteomic Analyses Reveals the Mechanism of Acupotomy Intervention on the Treatment of Knee Osteoarthritis in Rabbits.

Acupotomy intervention (AI) is an available treatment for knee osteoarthritis (KOA) in China, which is a common health problem over the world. However, the underlying mechanism of AI on the KOA treatment is still unknown. To further understand the mechanism of acupotomy in treating KOA, the morphological observation and TMT proteomic analyses were conducted in rabbits. By using X-ray and MRI, we found that the space of the knee joint was bigger in AI than in KOA. Moreover, the chondrocytes were neatly arranged in AI but disordered in KOA. With proteomic analyses in chondrocytes, 68 differently accumulated proteins (DAPs) were identified in AI vs. KOA and DAPs related to energy metabolism and the TCA cycle were suggested to play a central role in response to AI. Furthermore, AIFM1 was proposed to be an important regulator in controlling the energy production in mitochondrial. Besides, FN1, VIM, COL12A1, COL14A1, MYBPH, and DPYSL3 were suggested to play crucial roles in AI for the treatment of KOA. Our study was systematically elucidating the regulation mechanism of acupotomy intervention in the treatment of KOA.

A Combination of Surgical and Chemical Induction in a Rabbit Model for Osteoarthritis of the Knee.

Appropriate animal models of osteoarthritis (OA) are essential to develop new treatment modalities for OA. A combination of surgical and chemical induction could be appropriate for OA models. Rabbit knee OA models developed by surgical induction (anterior cruciate ligament transection [ACLT]), chemical induction (monosodium iodoacetate [MIA] injection), and a combination of both were compared to assess compositional and structural destruction of the knee joint. Twenty-one New Zealand white rabbits were randomly divided into 3 groups to induce OA (group 1: ACLT, n = 3; group 2: MIA [3, 6, 9mg] injection, n = 9; group 3: ACLT + MIA [3, 6, 9mg] injection, n = 9). In all groups, the Modified Mankin score was significantly higher in the osteoarthritis-induced knee than in the control. Modified Mankin scores were compared by category. The ACLT group was observed to score high in cartilage structure. In the MIA group, chondrocytes and matrix staining showed higher scores, and the ACLT+MIA group scored higher in all categories for cartilage structure, chondrocytes, matrix staining, and tidemark integrity. The ACLT + 3 mg MIA showed definite OA characteristics such as cartilage surface destruction and degeneration of cartilage layers, and the ACLT + 6 mg MIA and ACLT + 9 mg MIA showed more prominent OA characteristics such as cartilage surface destruction, matrix disorganization, and osteophyte formation. The combination of MIA injection and ACLT could be an appropriate method for OA induction in rabbit models.