Wnt5a deficiency in osteocalcin-expressing cells could not alleviate the osteoarthritic phenotype in a mouse model of post-traumatic osteoarthritis.

Objectives: Wnt5a, which regulates the activities of osteoblasts and osteoclasts, is reportedly overexpressed in osteoarthritis (OA) tissues. The purpose of this study was to elucidate its role in the development of OA by deleting Wnt5a in osteocalcin (OCN)-expressing cells. Materials and Methods: Knee OA was induced by anterior cruciate ligament transection (ACLT) in OCN-Cre;Wnt5afl/fl knockout (Wnt5a-cKO) mice and control littermates. Eight weeks after surgery, histological changes, cell apoptosis, and matrix metabolism of cartilage were evaluated by toluidine blue, TUNEL staining, and im-immunohistochemistry analyses, respectively. In addition, the subchondral bone microarchitecture of mice was examined by micro-computed tomography (micro-CT). Results: Histological scores show substantial cartilage degeneration occurred in ACLT knees, coupled with decreased collagen type II expression and enhanced matrix metalloproteinase 13 expression, as well as higher proportions of apoptotic cells. Micro-CT results show that ACLT resulted in decreased bone mineral density, bone volume/trabecular volume, trabecular number, and structure model index of subchondral bones in both Wnt5a-cKO and control littermates; although Wnt5a-cKO mice display lower BMD and BV/TV values, no significant difference was observed between Wnt5a-cKO and control mice for any of these values. Conclusion: Our findings indicate that Wnt5a deficiency in OCN-expressing cells could not prevent an osteoarthritic phenotype in a mouse model of post-traumatic OA.

Nail analysis for the assessment of caffeine abuse in Northwest China: A population-based study.

Caffeine is the most widely consumed psychoactive agent worldwide and has the potential for abuse, but studies monitoring caffeine abuse in China are scarce. This study aims to estimate the prevalence of caffeine abuse in northwest China and investigate the correlation between caffeine and other drugs in hair and nails using an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Fingernail clippings were collected from 376 participants in northwest China to detect caffeine and 13 other illicit psychoactive drugs and their metabolites. Paired hair and nail samples were collected from 39 participants to investigate the correlation between caffeine and other drugs in hair and nails. The samples were decontaminated, pulverized, and extracted by a high-throughput nail sample preparation method and analyzed by UPLC-MS/MS. The results showed a risk of caffeine abuse in northwest China, with concentrations ranging from 0.43 to 10.6 ng/mg for healthy volunteers, 0.49-246 ng/mg for caffeine abusers, and 0.25-363 ng/mg for drug addicts in community rehabilitation centers. Caffeine was detected together with other illicit psychoactive drugs and their metabolites. Furthermore, positive detection correlations were found between hair and nail samples. This study provides a current perspective on caffeine abuse in northwest China and demonstrates the practical use of UPLC-MS/MS for the simultaneous detection of caffeine and 13 illicit psychoactive drugs and their metabolites in hair and nails. The results highlight the potential of nails as a supplementary matrix when hair samples are unavailable and emphasize the need for handling caffeine carefully given its potential for abuse.

PTH (1-34) enhances the therapeutic effect of bone marrow mesenchymal stem cell-derived exosomes by inhibiting proinflammatory cytokines expression on OA chondrocyte repair in vitro.

BACKGROUND: The effects of bone marrow mesenchymal stem cells (BMSCs) during the treatment of cartilage damage have been proven to be attributed to paracrine mechanisms, particularly the effect of exosomes. Exosomes from different batches are inhomogeneous, and different treatment effects are observed between samples. The purpose of this research was to find more effective and homogeneous exosomes for the repair of chondrocytes in osteoarthritis (OA). We observed the potential effects and possible mechanisms of exosomes derived from parathyroid hormone (PTH) (1-34)-preconditioned BMSCs (ExoPTH) in the alleviation of OA. MATERIALS AND METHODS: Exosomes derived from BMSCs (ExoBMSC) and ExoPTH were isolated by differential centrifugation. Primary rat chondrocytes were used to establish the OA model by interleukin 1 beta (IL-1ß) in vitro. The effects of these two types of exosomes on OA chondrocyte proliferation, migration, apoptosis, and extracellular matrix formation were measured and compared. We observed changes in IL-2, TNF-α, and IL-6 levels via Western blotting (WB), and quantitative real-time PCR (qRT-PCR). RESULTS: We successfully extracted ExoBMSC and ExoPTH and established an IL-1ß-induced OA model in primary chondrocytes from rats. Our study showed that IL-2, TNF-α, and IL-6 levels increased significantly in OA chondrocytes; however, both ExoBMSC and ExoPTH reduced the levels of IL-2, TNF-α, and IL-6. In addition, ExoPTH exhibited stronger anti-inflammatory effects. ExoPTH had a more marked effect on proliferation, migration, and production of the extracellular matrix (Col-II) in OA chondrocytes than ExoBMSC at 24 h. CONCLUSION: ExoPTH increased the migration, proliferation, and chondral matrix formation of OA chondrocytes in vitro. In OA chondrocyte therapy, the potential mechanism of ExoPTH might involve the inhibition of production of proinflammatory cytokines. Although the two types of exosomes had some similar effects, most effects of ExoPTH were better than those of ExoBMSC, so ExoPTH may have a better ability to alleviate OA.

The Protective Effects of Parathyroid Hormone (1-34) on Cartilage and Subchondral Bone Through Down-Regulating JAK2/STAT3 and WNT5A/ROR2 in a Collagenase-Induced Osteoarthritis Mouse Model.

OBJECTIVE: To assess the effects of PTH (1-34) on bone and cartilage metabolism in a collagenase-induced mouse model of osteoarthritis (OA) and examine whether PTH (1-34) affects the expression of JAK2/STAT3 and WNT5A/ROR2 in this process. METHODS: Eighteen 12-week-old male C57Bl/6 mice were randomly assigned into three groups as follows: sham group (Group A), the collagenase + saline injection group (Group B), and the collagenase + PTH (1-34) treatment group (Group C). Collagenase was injected (intra-articular) into the knee joint of Group B and C. The PTH (1-34)-treatment was started at 6 weeks after the operation and lasted for 6 weeks. Cartilage pathology was evaluated by gross visual, histological, and immunohistochemical assessments. Subchondral bone was evaluated by microcomputed tomography (micro-CT) and immunohistochemical analyses. RESULTS: The OARSI macroscopic and microscopic scores of Group B were higher than those of Group A (P = 0.026; P = 0.002, respectively). Group C showed statistically significant differences in macroscopic and microscopic scores from Group B (P = 0.041; P = 0.008, respectively). The results showed that the Col-II and AGG expression levels in the cartilage tissue were significantly lower in Group B than Group A (P < 0.001; P = 0.008, respectively). The Col-II and AGG expression levels were significantly higher in Group C than Group B (P = 0.009; P = 0.014, respectively). MMP-13, ADAMTS-4, Caspase-3, P53, and Bax expression levels were significantly higher in Group B than the Group A (P < 0.001; P < 0.001; P = 0.04; P < 0.001; P = 0.005, respectively); however, the cartilage tissue in Group C showed significantly less ADAMTS-4, MMP-13, Caspase-3, P53, and Bax expression than Group B (P < 0.001, P < 0.001, P = 0.044; P = 0.002; P = 0.005, respectively). Over-expressed JAK2/STAT3 and WNT5A/ROR2 were observed in both cartilage and subchondral bone in this model; however, these changes were prevented by PTH (1-34) treatment. These parameters (bone mineral density, bone volume ratio, trabecular bone pattern factor, and structure model index) of micro-CT indicated subchondral bone loss and architecture changes in Group B, but improvements in these parameters in Group C. CONCLUSIONS: PTH (1-34) exhibits protective effects on both cartilage and subchondral bone in a collagenase-induced OA mouse model, and it may be involved in down-regulating the expression of JAK2/STAT3 and WNT5A/ROR2.

Raloxifene inhibits the overexpression of TGF-ß1 in cartilage and regulates the metabolism of subchondral bone in rats with osteoporotic osteoarthritis.

Overexpression of transforming growth factor-beta 1 (TGF-ß1) and subchondral bone remodelling play key roles in osteoarthritis (OA). Raloxifene (RAL) reduces the serum level of TGF-ß1 in postmenopausal women. However, the effect of RAL on TGF-ß1 expression in articular cartilage is still unclear. Therefore, we aimed to investigate the protective effect of RAL on osteoporotic osteoarthritis via affecting TGF-ß1 expression in cartilage and the metabolism of subchondral bone. Osteoporotic osteoarthritis was induced by a combination of anterior cruciate transection (ACLT) and ovariectomy (OVX). Rats were divided into five groups (n = 12): The sham group, the ACLT group, the OVX group, the ACLT + OVX group, and the RAL group (ACLT + OVX + RAL, 6.25 mg/kg/day for 12 weeks). Assessment was performed by histomorphology, microcomputed tomography (micro-CT) scan, immunohistochemistry, and tartrate-resistant acid phosphatase (TRAP) staining. We found that severe cartilage degeneration was shown in the ACLT + OVX group. The histomorphological scores, the levels of TGF-ß1, and its related catabolic enzymes and osteoclasts numbers in the ACLT + OVX group were higher than those in other groups (p < 0.05). Furthermore, structure model index (SMI) and trabecular spacing (Tb.Sp) were decreased (p < 0.05), while bone mineral density (BMD), bone volume fraction (BV/TV), and trabecular number (Tb.N) were increased by RAL compared with the ACLT + OVX group (p < 0.05). Our findings demonstrated that RAL in clinical doses retards the development of osteoporotic osteoarthritis by inhibiting the overexpression of TGF-ß1 in cartilage and regulating the metabolism of subchondral bone. These results provide support for RAL in the expansion of clinical indication for prevention and treatment in postmenopausal osteoarthritis.

Parathyroid hormone (1-34) ameliorates cartilage degeneration and subchondral bone deterioration in collagenase-induced osteoarthritis model in mice.

AIMS: Parathyroid hormone (PTH) (1-34) exhibits potential in preventing degeneration in both cartilage and subchondral bone in osteoarthritis (OA) development. We assessed the effects of PTH (1-34) at different concentrations on bone and cartilage metabolism in a collagenase-induced mouse model of OA and examined whether PTH (1-34) affects the JAK2/STAT3 signalling pathway in this process. METHODS: Collagenase-induced OA was established in C57Bl/6 mice. Therapy with PTH (1-34) (10 µg/kg/day or 40 µg/kg/day) was initiated immediately after surgery and continued for six weeks. Cartilage pathology was evaluated by gross visual, histology, and immunohistochemical assessments. Cell apoptosis was analyzed by TUNEL staining. Microcomputed tomography (micro-CT) was used to evaluate the bone mass and the microarchitecture in subchondral bone. RESULTS: Enhanced matrix catabolism, increased apoptosis of chondrocytes in cartilage, and overexpressed JAK2/STAT3 and p-JAK2/p-STAT3 were observed in cartilage in this model. All of these changes were prevented by PTH (1-34) treatment, with no significant difference between the low-dose and high-dose groups. Micro-CT analysis indicated that bone mineral density (BMD), bone volume/trabecular volume (BV/TV), and trabecular thickness (Tb.Th) levels were significantly lower in the OA group than those in the Sham, PTH 10 µg, and PTH 40 µg groups, but these parameters were significantly higher in the PTH 40 µg group than in the PTH 10 µg group. CONCLUSION: Intermittent administration of PTH (1-34) exhibits protective effects on both cartilage and subchondral bone in a dose-dependent manner on the latter in a collagenase-induced OA mouse model, which may be involved in regulating the JAK2/STAT3 signalling pathway.Cite this article: Bone Joint Res 2020;9(10):675-688.

Salmon calcitonin exerts better preventive effects than celecoxib on lumbar facet joint degeneration and long-term tactile allodynia in rats.

OBJECTIVE: To evaluate and compare the effects of salmon calcitonin (sCT) and celecoxib (CLX) on cartilage, subchondral bone and tactile allodynia in a rat model of lumbar facet joint (FJ) osteoarthritis (OA). METHOD: Forty 3-month-old male Sprague-Dawley rats were randomly divided into four groups: 30 received surgical collagenase (type II) injections in the right L3-L6 facet joints followed by 8 weeks of treatment with normal saline, CLX or sCT, and the other 10 received sham surgery. Tactile allodynia, changes of cartilage and subchondral bone of the L4-L5 FJs, and serum biomarkers were analyzed for all rats. RESULTS: Both sCT and CLX ameliorated cartilage lesions, significantly increased aggrecan expression and decreased caspase-3 expression. sCT also decreased the expression of a disintegrin and metalloproteinase with thrombospondin motifs 4 (ADAMTS-4). According to the micro-computed tomography (micro-CT) analysis, sCT significantly improved microarchitecture parameters of subchondral bone and micro-CT score; and inhibited articular process hypertrophy. CLX showed better antihyperalgesic effects than sCT on days 3 and 7 postoperatively despite no statistical differences, whereas sCT possessed better analgesic effects than CLX on days 42 and 56. Besides, the sCT treatment reduced the elevated cartilage oligomeric matrix protein (COMP) concentration in rats injected with collagenase (type II). CONCLUSIONS: Both sCT and CLX exerted preventive effects on FJ OA caused by collagenase (type II), but sCT showed more protective effects, particularly on maintaining cartilage metabolism, restraining the deterioration of the subchondral bone microarchitecture and tactile allodynia, and reducing serum COMP concentrations.

Strontium ranelate causes osteophytes overgrowth in a model of early phase osteoarthritis.

BACKGROUND: Osteoarthritis (OA) involves cartilage changes as well as modifications of subchondral bone and synovial tissues. Strontium ranelate (SR), an anti-osteoporosis compound, which is currently in phase III clinical trial for treatment of OA. Evidences suggest that SR preferably deposited in osteophyte, other than in subchondral bone in early phase of OA. This phenomenon raises concern about its utility for OA treatment as a disease-modifying drug. To evaluate the effect of SR on cartilage, subchondral bone mass and subchondral trabecular bone structure in medial meniscectomized (MNX) guinea pigs. METHOD: Thirty-six 3-month-old male Dunkin Hartley albino guinea pigs received either sham or medial meniscectomy operations. One week after the procedure, meniscectomized animals began 12 weeks of SR (625 mg/kg, daily) treatment by oral gavage for MNX + SR group, or normal saline for MNX + V group. All animals were euthanized 12 weeks later, cartilage degeneration and subchondral bone micro-architecture was analyzed. RESULTS: Both OARSI scores (P = 0.523 for marcoscopic scores, P = 0.297 for histological scores) and Cartilage thickness (P = 0.335) in MNX + SR group were comparable to MNX + V group. However, osteophyte sizes were larger in MNX + SR group (P = 0.014), and collapsed osteophytes in MNX + SR group (7 by 12) were significantly more than in MNX + V group (1 by 12) (P = 0.027), while immunohistochemistry indicates catabolic changes in osteophyte/plateau junction. Micro-CT analysis showed bone mineral density (BMD) (P = 0.001), bone volume fraction (BV/TV) (P = 0.008), trabecular spacing (Tb.Sp) (P = 0.020), trabecular thickness (Tb.Th) (P = 0.012) and structure model index (SMI) (P = 0.005) levels to be significantly higher in the MNX + SR group than in the MNX + V group. CONCLUSIONS: SR (625 mg/kg/day) did not protect cartilage from degeneration in MNX guinea pigs but subchondral bone was significantly enhanced. In early phase OA, SR administration causes osteophyte overgrowth, which may be related to incorporation into mineralizing osteophytes. This adverse effect is important for future studies of SR in OA.

Are estrogen-related drugs new alternatives for the management of osteoarthritis?

Osteoarthritis (OA) is a chronic degenerative disease involving multiple physiopathological mechanisms. The increased prevalence of OA after menopause and the presence of estrogen receptors in joint tissues suggest that estrogen could help prevent development of OA. This review summarizes OA research with a focus on the effects of estrogen and selective estrogen receptor modulators (SERMs). Preclinical studies and clinical trials of estrogen therapy have reported inconsistent results. However, almost all studies assessing SERM treatment have obtained more consistent and favorable effects in OA with a relatively safety and tolerability profiles. At present, some SERMs including raloxifene and bazedoxifene have been approved for the treatment of osteoporosis. In summary, estrogen-related agents may exert both a direct effect on subchondral bone and direct and/or indirect effects upon the surrounding tissues, including the articular cartilage, synovium, and muscle, to name a few. Estrogen and SERMs may be particularly favorable for postmenopausal patients with early-stage OA or osteoporotic OA, a phenotype defined by reduced bone mineral density related to high remodeling in subchondral bone. At present, no single drug exists that can prevent OA progression. Although estrogen-related drugs provide insight into the continued work in the field of OA drug administration, further research is required before SERMs can become therapeutic alternatives for OA treatment.