Systemic effects of platelet-rich plasma local injection on serum and urinary anabolic metabolites: A prospective randomized study.

Platelet-rich plasma (PRP) is widely utilized in the treatment of sports injuries. However, potential systemic effects after localized PRP injection are unclear at present. In this prospective randomized study, 24 Taiwanese male athletes with tendinopathy were randomized into a PRP group (n = 13) or a saline group (n = 11). The concentrations of serum and urine biomarkers were quantified by enzyme-linked immunosorbent assay assessment as well as gas chromatographic and mass spectrometric analysis, respectively. The results showed no significant differences in serum levels of growth hormone, insulin-like growth factor-1, insulin-like growth factor-binding protein 3, vascular endothelial growth factor, platelet-derived growth factor-BB, or serum substance P(SP) between the two groups before intervention, nor at 1, 2, or 7 days after intervention. However, a significant decrease in the serum SP level 1 and 7 days after PRP injection was observed. Regarding urinary concentrations of metabolites of anabolic androgenic steroids (AAS), no between-group differences before intervention, nor at 1, 2, or 7 days after intervention, were observed. Our study failed to observe significant surge of serum anabolic molecules and urinary excretion of anabolic AAS metabolites after PRP injection.

MicroRNA-128a represses chondrocyte autophagy and exacerbates knee osteoarthritis by disrupting Atg12.

Chondrocyte loss is a prominent feature of osteoarthritis (OA). Autophagy is indispensable in maintaining the metabolic activities of cells exposed to deleterious stress. The contribution of microRNA signaling to chondrocyte autophagy in OA development remains elusive. We uncovered an association between poor autophagy and increased miR-128a expressions in articular chondrocytes of patients with end-stage knee OA and in a rat anterior cruciate ligament transection (ACLT) model for OA development. Cartilage matrix degradation and severe OA histopathology was evident upon forced miR-128a expression within the articular compartment. Intra-articular injections with miR-128a antisense oligonucleotide stabilized chondrocyte autophagy and slowed ACLT-mediated articular tissue destruction, including cartilage erosion, synovitis, osteophyte formation, and subchondral plate damage. In vitro, miR-128 signaling hindered Atg12 expression, LC3-II conversion, and autophagic puncta formation through targeting the 3'-untranslated region of Atg12. It increased apoptotic programs, diminishing cartilage formation capacity of articular chondrocytes. Inactivating histone methyltransferase EZH2 reduced methyl histone H3K27 enrichment in the miR-128a promoter and upregulated miR-128a transcription in inflamed chondrocytes. Taken together, miR-128a-induced Atg12 loss repressed chondrocyte autophagy to aggravate OA progression. EZH2 inactivation caused H3K27 hypomethylation to accelerate miR-128a actions. Interruption of miR-128a signaling attenuated chondrocyte dysfunction and delayed OA development. Our data provide new insights into how miR-128a signaling affects chondrocyte survival and articular cartilage anabolism and highlight the potential of miR-128a targeting therapy to alleviate knee OA.

Sclerostin vaccination mitigates estrogen deficiency induction of bone mass loss and microstructure deterioration.

Sclerostin (SOST) is a Wnt signaling inhibitor detrimental to osteogenic differentiation and bone mineral acquisition. While control of SOST action delays the pathogenesis of skeletal disorders, the effects of SOST vaccination on the estrogen deficiency-induced bone deterioration remain elusive. In this study, we generated a SOST-Fc fusion protein which was composed of a SOST peptide Pro-Asn-Ala-Ile-Gly along with an IgG Fc fragment. SOST-Fc vaccination increased serum anti-SOST antibody levels and reduced serum SOST concentrations in mice. In vitro, anti-SOST serum attenuated the SOST-induced inhibition of osteogenic gene expression in osteoblast cultures. Administration with SOST-Fc increased serum levels of bone formation marker osteocalcin and alleviated the ovariectomy escalation of serum resorption markers CTX-1 and TRAP5b concentrations. It remarkably lessened the estrogen deficiency-mediated deterioration of bone mineral density, morphometric characteristics of trabecular bone, and mechanical strength of femurs and lumbar spines. The SOST-Fc-treated skeletal tissue exhibited moderate responses to the adverse actions of ovariectomy to bone mineral accretion, osteoclast surface, trabecular separation, and fatty marrow histopathology. SOST-Fc treatment increased serum osteoclast-inhibitory factor osteoprotegrin levels in conjunction with strong Wnt3a, ß-catenin, and TCF4 immunostaining in osteoblasts, whereas it weakened the estrogen deficiency enhancement of osteoclast-promoting factor receptor activator of nuclear factor-κB ligand. Taken together, blockade of SOST action by SOST-Fc vaccination sustains Wnt signaling, which harmonizes bone mineral accretion and resorption reactions and thereby ameliorates ovariectomy-induced bone loss. This study highlights SOST-Fc fusion protein as a new molecular therapeutic potential for preventing from osteoporotic disorders.

Subchondral mesenchymal stem cells from osteoarthritic knees display high osteogenic differentiation capacity through microRNA-29a regulation of HDAC4.

Subchondral bone deterioration and osteophyte formation attributable to excessive mineralization are prominent features of end-stage knee osteoarthritis (OA). The cellular events underlying subchondral integrity diminishment remained elusive. This study was undertaken to characterize subchondral mesenchymal stem cells (SMSCs) isolated from patients with end-stage knee OA who required total knee arthroplasty. The SMSCs expressed surface antigens CD29, CD44, CD73, CD90, CD105, and CD166 and lacked CD31, CD45, and MHCII expression. The cell cultures exhibited higher proliferation and greater osteogenesis and chondrogenesis potencies, whereas their population-doubling time and adipogenic lineage commitment were lower than those of bone marrow MSCs (BMMSCs). They also displayed higher expressions of embryonic stem cell marker OCT3/4 and osteogenic factors Wnt3a, ß-catenin, and microRNA-29a (miR-29a), concomitant with lower expressions of joint-deleterious factors HDAC4, TGF-ß1, IL-1ß, TNF-α, and MMP3, in comparison with those of BMMSCs. Knockdown of miR-29a lowered Wnt3a expression and osteogenic differentiation of the SMSCs through elevating HDAC4 translation, which directly regulated the 3'-untranslated region of HDAC4. Likewise, transgenic mice that overexpressed miR-29a in osteoblasts exhibited a high bone mass in the subchondral region. SMSCs in the transgenic mice showed a higher osteogenic differentiation and lower HDAC4 signaling than those in wild-type mice. Taken together, high osteogenesis potency existed in the SMSCs in the osteoarthritic knee. The miR-29a modulation of HDAC4 and Wnt3a signaling was attributable to the increase in osteogenesis. This study shed an emerging light on the characteristics of SMSCs and highlighted the contribution of SMSCs in the exacerbation of subchondral integrity in end-stage knee OA. KEY MESSAGES: Subchondral MSCs (SMSCs) from OA knee expressed embryonic stem cell marker Oct3/4. The SMSCs showed high proliferation and osteogenic and chondrogenic potencies. miR-29a regulated osteogenesis of the SMSCs through modulation of HDAC4 and Wnt3a. A high osteogenic potency of the SMSCs existed in mice overexpressing miR-29a in bone. Aberrant osteogenesis in SMSCs provides a new insight to subchondral damage in OA.

MicroRNA-29a Counteracts Synovitis in Knee Osteoarthritis Pathogenesis by Targeting VEGF.

Synovitis contributes to the development of osteoarthritis (OA) of the knee. MicroRNAs regulate joint microenvironment homeostasis and deterioration. This study was undertaken to characterize the actions of microRNA-29a (miR-29a) to synovial remodeling in OA joints. Synovial specimens isolated from patients with end-stage OA knees showed abundant fibrotic matrix and vessel histopathology concomitant with weak miR-29a expression. In vitro, miR-29a knockdown caused synovial fibroblasts to exhibit high expressions of collagen III, TGF-ß1, MMP9, MMP13, and ADAMTS5, whereas miR-29a overexpression diminished these joint-deleterious factors. In collagenase-mediated OA pathogenesis, miR-29a-overexpressing transgenic mice showed minor responses to hyperplasia, macrophage infiltration, fibrosis, hyperangiogenesis, and VEGF expression in synovial lesions. These effects mitigated articular cartilage loss and gait aberrance of injured joints. Intra-articular administration of miR-29a precursor lessened the collagenase aggravation of excessive synovial remodeling reactions and thereby sustained joint tissue integrity. miR-29a lowered VEGF production and angiogenic activities in synovial fibroblasts through targeting the 3'-UTR of VEGF. Taken together, miR-29a deficiency exacerbated synovitis pathogenesis in the end-stage OA knees. miR-29a signaling fends off excessive synovial angiogenesis and fibrosis, which delays joint destruction. This study sheds new light on the protective effects against synovial deterioration and the therapeutic advantage of miR-29a in OA knees.

Histone demethylase UTX counteracts glucocorticoid deregulation of osteogenesis by modulating histone-dependent and -independent pathways.

Excess glucocorticoid administration impairs osteogenic activities, which raises the risk of osteoporotic disorders. Epigenetic methylation of DNA and histone regulates the lineage commitment of progenitor cells. This study was undertaken to delineate the actions of histone lysine demethylase 6a (UTX) with regard to the glucocorticoid impediment of osteogenic differentiation. Osteogenic progenitor cells responded to supraphysiological glucocorticoid by elevating CpG dinucleotide methylation proximal to transcription start sites within Runx2 and osterix promoters and Wnt inhibitor Dickkopf-1 (Dkk1) expression concomitant with low UTX expression. 5'-Aza-deoxycystidine demethylation of Runx2 and osterix promoters abolished the glucocorticoid inhibition of mineralized matrix accumulation. Gain of UTX function attenuated the glucocorticoid-induced loss of osteogenic differentiation, whereas UTX silencing escalated adipogenic gene expression and adipocyte formation. UTX sustained osteogenic gene transcription through maintaining its occupancy to Runx2 and osterix promoters. It also mitigated the trimethylation of histone 3 at lysine 27 (H3K27me3), which reduced H3K27me3 enrichment to Dkk1 promoter and thereby lowered Dkk1 transcription. Modulation of ß-catenin and Dkk1 actions restored UTX signaling in glucocorticoid-stressed cells. In vivo, UTX inhibition by exogenous methylprednisolone and GSK-J4 administration, an effect that disturbed H3K27me3, ß-catenin, Dkk1, Runx2, and osterix levels, exacerbated trabecular microarchitecture loss and marrow adiposity. Taken together, glucocorticoid reduction of UTX function hindered osteogenic differentiation. Epigenetic hypomethylation of osteogenic transcription factor promoters and H3K27 contributed to the UXT alleviation of Dkk1 transcription and osteogenesis in glucocorticoid-stressed osteogenic progenitor cells. Control of UTX action has an epigenetic perspective of curtailing glucocorticoid impairment of osteogenic differentiation and bone mass. KEY MESSAGES: UTX attenuates glucocorticoid deregulation of osteogenesis and adipogenesis. UTX reduces Runx2 promoter methylation and H3K27me3 enrichment in the Dkk1 promoter. ß-catenin and Dkk1 modulate the glucocorticoid inhibition of UTX signaling. UTX inhibition exacerbates bone mass, trabecular microstructure and fatty marrow. UTX signaling is indispensable in fending off glucocorticoid-impaired osteogenesis.

Chaperonin 60 regulation of SOX9 ubiquitination mitigates the development of knee osteoarthritis.

UNLABELLED: Articular cartilage integrity loss is a prominently deleterious feature of osteoarthritis (OA). The mechanistic underlying the development of OA warrants characterization. Heat shock proteins (HSPs), members of the chaperone family, reportedly orchestrate tissue homeostasis and remodeling in response to detrimental stress. This study was undertaken to characterize the biological role of HSP60 in the pathogenesis of OA knee. Articular specimens from OA knee patients displayed severe articular damage histopathology concomitant with low HSP60 concentrations in cartilage and synovial fluid compared to non-OA patients. In vitro, a gain of HSP60 signaling counteracted the IL-1ß-mediated suppression of mitochondrial biogenesis, chondrogenic transcription factor SOX9, and cartilage matrix expression of human chondrocytes cultures. Transgenic mice that overexpressed human HSP60 (TgHSP60) had higher chondrocyte proliferation and thicker articular cartilage than wild-type mice. In collagenase-induced OA knees, analyses of CatWalk, 2-deoxyglucose-probed fluorescence imaging, and µCT revealed that affected knees of TgHSP60 mice showed minor footprint irregularity, joint inflammation, and osteophyte formation. HSP60 overexpression also alleviated the histopathology of cartilage damage, synovial hypervascularization, and macrophage infiltration within joint lesions. Intra-articular administration of exogenous HSP60 ameliorated the pathogenesis of cartilage deterioration, synovitis, and osteophyte accumulation, thereby improving gait profiles of the collagenase-injured knees. HSP60 signaling maintains SOX9 levels by attenuating SOX9 hyper-ubiquitination of affected joints. Taken together, HSP60 deficiency in articular compartments was relevant to OA knee incidence. Sustained HSP60 signaling is favorable to mitigate the progression of OA. This study highlights the joint-anabolic actions of HSP60 and provides perspective on its therapeutic potential for OA. KEY MESSAGES: HSP60 deficiency is relevant to the existence of end-stage knee osteoarthritis. HSP60 overexpression attenuates cartilage matrix loss of inflammatory chondrocytes. HSP60 transgenic mice showed mild articular injury during knee osteoarthritis. HSP60 maintains knee joint homeostasis through reducing SOX9 ubiquitination. Control of cartilage-anabolic regulator HSP60 ameliorates knee osteoarthritis.

MicroRNA-29a mitigates glucocorticoid induction of bone loss and fatty marrow by rescuing Runx2 acetylation.

Glucocorticoid treatment reportedly increases the morbidity of osteoporotic or osteonecrotic disorders. Exacerbated bone acquisition and escalated marrow adipogenesis are prominent pathological features of glucocorticoid-mediated skeletal disorders. MicroRNAs reportedly modulate tissue metabolism and remodeling. This study was undertaken to investigate the biological roles of microRNA-29a (miR-29a) in skeletal and fat metabolism in the pathogenesis of glucocorticoid-induced osteoporosis. Transgenic mice overexpressing miR-29a precursor or wild-type mice were given methylprednisolone. Bone mass, microarchitecture and histology were assessed by dual energy X-ray absorptiometry, µCT and histomorphometry. Differential gene expression and signaling components were delineated by quantitative RT-PCR and immunoblotting. Glucocorticoid treatment accelerated bone loss and marrow fat accumulation in association with decreased miR-29a expression. The miR-29a transgenic mice had high bone mineral density, trabecular microarchitecture and cortical thickness. miR-29a overexpression mitigated the glucocorticoid-induced impediment of bone mass, skeletal microstructure integrity and mineralization reaction and attenuated fatty marrow histopathology. Ex vivo, miR-29a increased osteogenic differentiation capacity and alleviated the glucocorticoid-induced promotion of adipocyte formation in primary bone-marrow mesenchymal progenitor cell cultures. Through inhibition of histone deacetylase 4 (HDAC4) expression, miR-29a restored acetylated Runx2 and ß-catenin abundances and reduced RANKL, leptin and glucocorticoid receptor expression in glucocorticoid-mediated osteoporosis bone tissues. Taken together, glucocorticoid suppression of miR-29a signaling disturbed the balances between osteogenic and adipogenic activities, and thereby interrupted bone formation and skeletal homeostasis. miR-29a inhibition of HDAC4 stabilized the acetylation state of Runx2 and ß-catenin that ameliorated the detrimental effects of glucocorticoid on mineralization and lipogenesis reactions in bone tissue microenvironments. This study highlighted emerging skeletal-anabolic actions of miR-29a signaling in the progression of glucocorticoid-induced bone tissue destruction. Sustaining miR-29a actions is beneficial in protecting against glucocorticoid-mediated osteoporosis.

Extracorporeal shockwave therapy shows site-specific effects in osteoarthritis of the knee in rats.

PURPOSE: This study investigated the site-specific effects of extracorporeal shockwave therapy (ESWT) in osteoarthritis of the knee in rats. METHODS: Sixty SD rats were divided into five groups. Group I was the control and received sham surgery without anterior cruciate ligament transection (ACLT) and medial meniscectomy (MM) and no ESWT. Group II received ACLT + MM, but no ESWT. Group III received ACLT + MM and ESWT at distal femur. Group IV received ACLT + MM and ESWT at proximal tibia. Group V received ACLT + MM and ESWT at distal femur and proximal tibia. Each ESWT session consisted of 800 impulses at 14 kV (= 0.219 mJ/mm(2) energy flux density). The evaluations included radiograph, bone mineral density (BMD), histomorphologic examination, and immunohistochemical analysis. RESULTS: Radiographic appearance: Group II showed progressive osteoarthritis of the knee at 12 and 24 wk, whereas only subtle changes were noted in Groups I, III, VI, and V. BMD results: Group II showed significant decreases of BMD at 12 and 24 wk. The BMDs of Groups III, IV, and V were comparable to Group I. Cartilage degradation: Group II showed significant increases of Mankin score, Safranin O stain, and matrix metalloproteinase 13 and decrease of collagen II at 12 and 24 wk. The changes of Mankin score, Safranin O stain, matrix metalloproteinase 13, and collagen II in Groups III, IV, and V were comparable to Group I. Subchondral bone remodeling: Group II showed significant decreases of vascular endothelial growth factor, bone morphogenetic protein 2, and osteocalcin at 12 and 24 wk as compared to Group I. The changes of vascular endothelial growth factor, bone morphogenetic protein 2, and osteocalcin in Groups III, IV, and V were comparable to Group I. CONCLUSION: ESWT shows site-specific effects at distal femur and proximal tibia in osteoarthritis of the knee in rats. The effects of ESWT are consistent at distal femur and proximal tibia, with no additive effects when both areas were simultaneously treated.

Extracorporeal shockwave therapy shows a number of treatment related chondroprotective effect in osteoarthritis of the knee in rats.

BACKGROUND: Extracorporeal shockwave therapy (ESWT) shows chondroprotective effect in osteoarthritis of the rat knees. However, the ideal number of ESWT is unknown. This study investigated the effects of different numbers of ESWT in osteoarthritis of the knee in rats. METHODS: Forty-five male Sprague-Dawley rats were divided into five groups. Group I underwent sham arthrotomy without anterior cruciate ligament transection (ACLT) or medial meniscectomy (MM) and received no ESWT. Group II underwent ACLT + MM and received no ESWT. Group III underwent ACLT + MM, and received ESWT once a week for one treatment. Group IV underwent ACLT + MM and received ESWT twice a week for 2 treatments. Group V underwent ACLT + MM and received ESWT three times a week for 3 treatments. Each treatment consisted of 800 impulses of shockwave at 14 Kv to the medial tibia condyle. The evaluations included radiographs of the knee, histomorphological examination and immunohistochemical analysis at 12 weeks. RESULTS: At 12 weeks, group II and V showed more radiographic arthritis than groups I, III and IV. On histomorphological examination, the Safranin O matrix staining in groups III and IV are significantly better than in groups II and V, and the Mankin scores in groups III and IV are less than groups II and V. Groups III and IV showed significant decreases of Mankin score and increase of Safranin O stain as compared to group I. Group V showed significant increases of Mankin score and a decrease of Safranin O stain as compared to group II. In articular cartilage, group II showed significant increase of MMP13 and decrease of collagen II as compared to group I. Groups III and IV showed significant decrease of MMP13 and increase of collagen II as compared to group I. Group V showed significant increase of MMP13 and decrease of collagen II as compared to group II. In subchondral bone, vWF, VEGF, BMP-2 and osteocalcin significantly decreased in groups II and V, but increased in groups III and IV relative to group I. CONCLUSIONS: ESWT shows a number of treatment related chondroproctective effect in osteoarthritis of the knee in rats.

Dkk-1 promotes angiogenic responses and cartilage matrix proteinase secretion in synovial fibroblasts from osteoarthritic joints.

OBJECTIVE: Synovial hypervascularity is a prominent pathologic feature in osteoarthritic (OA) joints. Wnt inhibitor Dkk-1 contributes to joint remodeling. We undertook this study to investigate whether Dkk-1 regulates cartilage destruction activities in OA synovial fibroblasts. METHODS: Synovial tissues were harvested from knees of patients with OA and from injured knees of non-OA patients who underwent arthroscopy. Expression of Dkk-1, angiogenic factors (stromal cell-derived factor 1 and colony-stimulating factor 1), and cartilage proteinases (ADAMTS-5 and matrix metalloproteinase 3 [MMP-3]) as well as vascularity in synovium and synovial fluid were quantified using enzyme-linked immunosorbent assay, reverse transcription-polymerase chain reaction, and histomorphometry. Synovial fibroblasts were treated with interleukin-1ß (IL-1ß), anti-Dkk-1 antibody, and RNA interference to characterize their angiogenic activity. Rats with OA knees were administered Dkk-1 antisense oligonucleotide to verify synovial angiogenesis and cartilage integrity. RESULTS: OA synovium exhibited increased vascularity and expression of angiogenic factors and proteinases in association with up-regulated Dkk-1 levels. Neutralizing Dkk-1 reduced the inhibitory effects of OA synovial fluid on aggrecan expression in chondrocyte cultures. IL-1ß induction of Dkk-1 increased expression of hypoxia-inducible factor 1α (HIF-1α), angiogenic factors, ADAMTS-5, and MMP-3 in synovial fibroblasts and promoted angiogenesis in vascular endothelial cells. Knockdown of HIF-1α decreased Dkk-1 enhancement of angiogenic factor expression. Stabilization of glycogen synthase kinase 3ß phosphorylated at Ser(9) , ß-catenin, T cell factor 4, and ERK signaling attenuated Dkk-1 up-regulation of angiogenic factor and proteinase expression in synovial fibroblasts. In vivo, Dkk-1 interference reduced the expression of angiogenic factors and proteinases and ameliorated synovial vascularity and cartilage deterioration in knees of rats with OA. CONCLUSION: Dkk-1 promoted angiogenic and cartilage degradation activities in synovial fibroblasts, which accelerated synovial angiogenesis and cartilage destruction. Dkk-1 blockade has therapeutic potential for reducing OA-induced synovitis and joint deterioration.

Extracorporeal shockwave therapy shows time-dependent chondroprotective effects in osteoarthritis of the knee in rats.

BACKGROUND: Recent studies reported that extracorporeal shockwave therapy (ESWT) has a chondroprotective effect on the initiation and regression of osteoarthritis of the knee in rats. However, the time course effects of ESWT in the osteoarthritic knee are not fully understood. The purpose of this study was to evaluate the effects of ESWT over time on osteoarthritis of the knee in rats. METHODS: We used 72 8-week-old male Sprague-Dawley rats with body weights ranging from 245 to 265 g. We randomly divided the rats into three groups, with 24 rats in each group. The control group received neither surgery nor ESWT. The anterior cruciate ligament transected (ACLT) group underwent anterior cruciate ligament transection but received no ESWT. The ACLT plus ESWT group underwent ACL transection and received ESWT at 1 wk after surgery. The animals were killed at 2, 4, 8, and 12 wk, 6 rats from each group at each time course. Evaluation parameters included Mankin score, Safranin O stain, and collagen II for the articular cartilage; and vascular endothelial growth factor (VEGF), bone morphogenetic-2 (BMP-2), and osteocalcin for the subchondral bone using histopathological examination and immunohistochemical analysis. RESULTS: The ACLT group showed significant increases in Mankin score and Safranin O stain, and a decrease in collagen II in the articular cartilage, and significant decreases in VEGF, BMP-2, and osteocalcin in the subchondral bone compared with the control (P < .05). The ACLT + ESWT group showed significant decreases in Mankin score and Safranin O stain and an increase in collagen II in the articular cartilage, and significant increases in VEGF, BMP-2, and osteocalcin in the subchondral bone compared with the control group. The changes in the ACLT + ESWT group appeared to correlate with the time courses of treatment; the most beneficial effects were noticed 4 weeks after ESWT. CONCLUSION: Extracorporeal shockwave therapy is effective in preventing osteoarthritis of the knee in rats. The beneficial effects of ESWT appear to be time-dependent beginning at 4 weeks after treatment.

Shockwaves enhance the osteogenetic gene expression in marrow stromal cells from hips with osteonecrosis.

BACKGROUND: This in vitro study investigated the angiogenesis and osteogenesis effects of shockwaves on bone marrow stromal cells (BMSCs) from hips with osteonecrosis. METHODS: BMSCs were harvested from the bone marrow cavity of the proximal femur in six patients with osteonecrosis of the femoral head. The specimens were divided into four groups, the control, shockwave, shockwave plus nω-nitro- L-arginine methyl ester (L-NAME) and a nitric oxide (NO) donor (NOC18) groups. The control group received no shockwaves and was used as the baseline. The shockwave group received 250 shockwave impulses at 14 Kv (equivalent to 0.18 mJ/mm2 energy flux density). The shockwave plus LNAME group was pre-treated with L-NAME before receiving shockwaves. The NOC18 group received NOC18 after cell culture for 48 hours. The evaluations included cell proliferation (MTT) assay, alkaline phosphatase, real time reverse transcriptase-polymerase chain reaction analysis of vessel endothelial growth factor (VEGF), bone morphogenic protein (BMP)-2, RUNX2 and osteocalcin mRNA expression and von Kossa stain for mineralized nodules. RESULTS: The shockwave group showed significant increases in MTT, VEGF, alkaline phosphatase, BMP2, RUNX2 and osteocalcin mRNA expression and more mature mineralized nodules compared with the control. Pre-treatment with L-NAME significantly reduced the angiogenic and osteogenic effects of extracorporeal shockwave therapy (ESWT) and the results were comparable with the control. Administration of NOC18 significantly enhanced the angiogenesis and osteogenesis effects compared with the control and the results were comparable with the shockwave group. CONCLUSION: ESWT significantly enhanced the angiogenic and osteogenic effects of BMSCs mediated through the NO pathway in hips with osteonecrosis. These innovative findings, at least in part, explain some of the mechanism of shockwaves in osteonecrosis of the hip.

Extracorporeal shockwave therapy shows chondroprotective effects in osteoarthritic rat knee.

PURPOSE: This study investigated the effects of extracorporeal shockwave therapy (ESWT) on the subchondral bone and articular cartilage in the initiation of osteoarthritis of the knee in rats. METHODS: Anterior cruciate ligament transected (ACLT) osteoarthritis (OA) rat knee model was used in this study. Twenty-seven male Sprague-Dawley rats were divided into three groups. The control group underwent sham surgery without ACLT and received no ESWT. The ACLT group underwent ACLT, but received no ESWT. The ACLT plus ESWT group underwent ACLT and received ESWT immediately after surgery. The evaluation parameters included radiograph, bone mineral density, serum levels of cartilage oligometric protein and osteocalcin, and urinary concentration of C-telopeptide of type II collagen (CTX-II), and histomorphological examination. RESULTS: At 12 weeks, OA of the knee was radiographically verified in the ACLT group, but very subtle changes were noticed in the control and the ACLT plus ESWT groups. On articular cartilage, the ACLT group showed significant increases in cartilage degradation and chondrocyte apoptosis compared to the control and ACLT plus ESWT groups. The ACLT plus ESWT group demonstrated significant decrease in the cartilage degradation and an increase in chondrocyte activity comparable to the control. In subchondral bone, the ACLT group showed a significant decrease in bone remodeling as compared to the control and ACLT plus ESWT groups. The ACLT plus ESWT group showed significant improvement in bone remodeling comparable to the control. CONCLUSION: Extracorporeal shockwave therapy shows chondroprotective effect associated with improvement in subchondral bone remodeling in the initiation of ACLT OA knee model in rats.

Extracorporeal shockwave shows regression of osteoarthritis of the knee in rats.

BACKGROUND: This study investigated the effects of extracorporeal shockwave technology (ESWT) in osteoarthritis of the knee in rats. MATERIALS AND METHODS: Thirty-six Sprague-Dawley rats were randomly divided into three groups with 12 rats in each group. Group I was the control group and received neither anterior cruciate ligament transection (ACLT) nor ESWT. In groups II and III, ACLT was performed in left knee and osteoarthritis (OA) was verified at 12 wk. Group II received no ESWT, and group III received ESWT at 12 wk after ACLT. Radiographs and bone mineral density (BMD) were obtained at 0, 12, and 24 wk. The animals were sacrificed at 24 wk. One half of the animals were subjected to bone strength test, and the other half for histomorphologic examination and immunohistochemical analysis. RESULTS: Radiographs of the left knee showed progressive OA changes at 12 and 24 wk in group II, whereas, very subtle OA changes were noted in group I and group III. BMD and bone strength were significantly lower in group II compared with groups I and III, but no difference was noted between group I and group III. The cartilage degradations were significantly higher in group II compared with groups I and III, but no difference was noted between group I and group III. The subchondral bone remodeling was significantly less pronounced in group II compared with groups I and III, but no difference was noted between group I and group III. CONCLUSIONS: Application of ESWT to the subchondral bone of the medial tibia condyle showed regression of osteoarthritis of the knees in rats.

VEGF modulates angiogenesis and osteogenesis in shockwave-promoted fracture healing in rabbits.

OBJECTIVE: Strong vascular endothelial growth factor (VEGF) expression of osteoprogenitors was found in callus site during fracture healing. The aim of this study was to investigate whether VEGF modulates the angiogenesis and osteogenesis in shockwave-promoted fracture healing in rabbits. MATERIALS AND METHODS: Twenty-seven Japanese rabbits were used in the study. A fracture of left tibia with 5 mm gap was created, and the fracture was stabilized with an external fixator. The rabbits were randomly divided into three groups. Group I was the control group and received no shockwave therapy. Group II received shockwave therapy, and group III was pretreated with bevacizumab, a monoclonal antibody against VEGF, before receiving shockwave. Radiographs of the tibia were obtained at 1, 4, and 8 wk. Bone mineral density was performed at 8 wk. The rabbits were euthanized at 8 wk, and the bone specimens were subjected to histomorphological examination and immunohistochemical analysis. RESULTS: At 8 wk, radiographs showed considerably better bone healing and remodeling of the fracture in group II compared with groups I and III, whereas no discernable difference was noted between group I and group III. The BMD values were significantly higher in group II than groups I and III, but no difference noted between group I and group III. In histomorphological examination, significant increases in bone tissue was were noted in group II compared with groups I and III, but no difference was noted between group I and group III. In immunohistochemical analysis, significant increases in VEGF, vWF, PCNA, BMP-2 and osteocalcin, and a decrease in TUNEL expression were observed in group II compared with groups I and III, but no statistical difference was noted between group I and group III. CONCLUSION: Significant increases in VEGF and angiogenic and osteogenic growth factors were noted in shockwave-promoted bone healing. Pre-treatment with bevacizumab inhibited VEGF and in turn, attenuated the effect of shockwave. It appears that VEGF modulates angiogenesis and osteogenesis in shockwave-promoted bone healing in rabbits.

pCMV-BMP-2-transfected cell-mediated gene therapy in anterior cruciate ligament reconstruction in rabbits.

PURPOSE: This study investigated the effect of plasmid cytomegalovirus (pCMV)-bone morphogenetic protein 2 (BMP-2) gene therapy on the healing of the tendon-bone interface after anterior cruciate ligament (ACL) reconstruction in rabbits. METHODS: The pCMV-BMP-2 was synthesized from full-length human BMP-2 complementary deoxyribonucleic acid, followed by cloning into pCMV Script vector (Clontech Laboratories, Inc., San Jose, CA), and was delivered by a xenogeneic (rat kidney) cell line. The ACL was reconstructed by the transfer of extensor digital tendon in the proximal tibia. In the study group the pCMV-BMP-2 gene-transfected normal rat kidney cells mixed with calcium alginate gel were placed at the tendon-bone interface, whereas no pCMV-BMP-2 was used in the control group. The evaluations included radiography, bone mineral density, magnetic resonance imaging, biomechanical study, histologic examination, and immunohistochemical analysis. RESULTS: Bone mineral density showed no significant difference between the groups (P > .05). Magnetic resonance imaging showed significantly better contact between tendon and bone in the study group compared with the control group (P < .0001). In the biomechanical study, significantly higher failure load and maximal graft tension were noted in the study group compared with the control group (P = .034). The modes of graft failure were rupture of the tendon proper in 78% and graft pullout from the bone tunnel in 22% of specimens in the study group versus graft rupture in 22% and graft pullout in 78% in the control group (P = .018). On histologic examination, the study group showed significantly better integration between tendon and bone, as well as more bone tissue around the tendon graft, than the control group (P = .0004). On immunohistochemical analysis, the study group showed significantly higher expressions of von Willebrand factor, vascular endothelial growth factor, proliferation cell nuclear antigen, and BMP-2 than the control group (P < .05). CONCLUSIONS: The pCMV-BMP-2 gene therapy significantly improved the healing of tendon to bone and promoted angiogenesis and osteogenesis at the tendon-bone interface after ACL reconstruction in the rabbit model. CLINICAL RELEVANCE: Application of pCMV-BMP-2 gene therapy may be an effective adjunct therapy in ACL reconstruction.

Control of Dkk-1 ameliorates chondrocyte apoptosis, cartilage destruction, and subchondral bone deterioration in osteoarthritic knees.

OBJECTIVE: Perturbation of Wnt signaling components reportedly regulates chondrocyte fate and joint disorders. The Wnt inhibitor Dkk-1 mediates remodeling of various tissue types. We undertook this study to examine whether control of Dkk-1 expression prevents joint deterioration in osteoarthritic (OA) knees. METHODS: Anterior cruciate ligament transection-and collagenase-induced OA in rat knees was treated with end-capped phosphorothioate Dkk-1 antisense oligonucleotide (Dkk-1-AS). Articular cartilage destruction, cartilage degradation markers, bone mineral density (BMD), and subchondral trabecular bone volume of injured knee joints were measured using Mankin scoring, enzyme-linked immunosorbent assay, dual x-ray absorptiometry, and histomorphometry. Dkk-1-responsive molecule expression and apoptotic cells in knee tissue were detected by quantitative reverse transcriptase-polymerase chain reaction, immunoblotting, and TUNEL staining. RESULTS: Up-regulated Dkk-1 expression was associated with increased Mankin score and with increased serum levels of cartilage oligomeric matrix protein and C-telopeptide of type II collagen (CTX-II) during OA development. Dkk-1-AS treatment alleviated OA-associated increases in Dkk-1 expression, Mankin score, cartilage fibrillation, and serum cartilage degradation markers. Dkk-1-AS also alleviated epiphyseal BMD loss and subchondral bone exposure associated with altered serum levels of osteocalcin and CTX-I. The treatment abrogated chondrocyte/osteoblast apoptosis and subchondral trabecular bone remodeling in OA. Dkk-1 knockdown increased levels of nuclear beta-catenin and phosphorylated Ser(473)-Akt but attenuated expression of inflammatory factors (Toll-like receptor 4 [TLR-4], TLR-9, interleukin-1beta, and tumor necrosis factor alpha), the apoptosis regulator Bax, matrix metalloproteinase 3, and RANKL in OA knee joints. CONCLUSION: Interference with the cartilage- and bone-deleterious actions of Dkk-1 provides therapeutic potential for alleviating cartilage destruction and subchondral bone damage in OA knee joints.

The effect of shock wave treatment at the tendon-bone interface-an histomorphological and biomechanical study in rabbits.

PURPOSE: This study was performed to investigate the effect of shock wave treatment on the healing at tendon-bone interface in rabbits. MATERIALS AND METHODS: Thirty-six New Zealand White rabbits were used in this study. The anterior cruciate ligament was excised and replaced with the long digital extensor. The right knees (study group) were treated with 500 impulses of shock waves at 14 kV, while the left knees (control group) received no shock waves. Histomorphological studies were performed in 24 rabbits at 1, 2, 4, 8, 12 and 24 weeks. Biomechanical studies were performed in 12 rabbits at 12 and 24 weeks. RESULTS: There was significantly more trabecular bone around the tendons noted in the study group compared with the control group at different time intervals after 4 weeks (P<0.05). The contacting between bone and tendon was significantly better in the study group than the control group after 8 weeks (P<0.05). The tensile strength of the tendon-bone interface was significantly higher in the study group than the control group at 24 weeks (P=0.018), whereas similar modes of graft failure were noted between the two groups. CONCLUSION: Shock wave treatment significantly improves the healing rate of the tendon-bone interface in a bone tunnel in rabbits. The effect of shock waves appears to be time-dependent.

Secreted frizzled-related protein 1 modulates glucocorticoid attenuation of osteogenic activities and bone mass.

Prolonged glucocorticoid treatment is known to cause osteoporosis or aseptic necrosis. Secreted frizzled-related proteins 1 (SFRP1) and low-density lipoprotein-related protein 5 (LRP5), a Wnt protein antagonist and a coreceptor, have been found to regulate skeletogenesis. Whereas recent studies have reported that excess glucocorticoid promotes bone loss, the biological role of SFRP1 and LRP5 in regulating glucocorticoid attenuation of bone formation is not fully understood. We showed that a supraphysiological level of glucocorticoid enhanced SFRP1 but not LRP5 expression of primary mesenchymal cell cultures in vitro and osteoblasts at metaphyseal trabecular endosteum and chondrocytes at calcified cartilage in vivo. Glucocorticoid augmentation of SFRP1 expression was transcriptionally mediated. The inhibitory action of glucocorticoid on osteogenic differentiation appeared to be regulated by SFRP1 mediation of beta-catenin destabilization because knocking down SFRP1 by RNA interference abrogated the supraphysiological level of glucocorticoid attenuation of osteogenesis. Recombinant human SFRP1 reduced the promoting effect of physiological level of glucocorticoid on cytosolic beta-catenin accumulation, runt-related transcription factor-2 activation, and osteogenic activities. Glucocorticoid and recombinant human SFRP1 significantly increased osteochondral cell apoptosis associated with reduced mineral density, biomechanical properties, trabecular bone volume, and midshaft cortical bone areas in rat femurs. These findings suggest that SFRP1 modulates glucocorticoid-induced bone loss. Regulation of Wnt/SFRP signal transduction can be used in the future as an alternative strategy for the prevention of glucocorticoid-induced osteoporosis.