Tomohiro Onodera

Btbd7 Regulates Epithelial Cell Dynamics and Branching Morphogenesis

Epithelial Cleft Formation The internal architecture of many embryonic organs is established by repetitive branching of epithelia. Epithelial clefts and outgrowths generate this internal branching of glands and other organs. Onodera et al. (p. 562) identify a gene, Btbd7, as a regulator of epithelial dynamics and cleft formation, linking the extracellular matrix with morphogenesis. Btbd7 is induced by a matrix protein at sites of cleft progression and induces a transcription factor and suppresses cell adhesion. The resulting local cell separation and motility contribute to transient tissue gaps that contribute to clefts that help form branched organs. A regulatory gene suppresses cell adhesion and enhances cell motility to help form branched organs. During embryonic development, many organs form by extensive branching of epithelia through the formation of clefts and buds. In cleft formation, buds are delineated by the conversion of epithelial cell-cell adhesions to cell-matrix adhesions, but the mechanisms of cleft formation are not clear. We have identified Btbd7 as a dynamic regulator of branching morphogenesis. Btbd7 provides a mechanistic link between the extracellular matrix and cleft propagation through its highly focal expression leading to local regulation of Snail2 (Slug), E-cadherin, and epithelial cell motility. Inhibition experiments show that Btbd7 is required for branching of embryonic mammalian salivary glands and lungs. Hence, Btbd7 is a regulatory gene that promotes epithelial tissue remodeling and formation of branched organs.

Intraoperative medial pivot affects deep knee flexion angle and patient-reported outcomes after total knee arthroplasty.

The aim of this study was to evaluate the relationship between clinical results including patient-reported outcomes and intraoperative knee kinematic patterns after total knee arthroplasty (TKA). A cross-sectional survey of forty consecutive medial osteoarthritis patients who had a primary TKA using a CT-based navigation system was conducted. Subjects were divided into two groups based on intraoperative kinematic patterns: a medial pivot group (n = 20) and a non-medial pivot group (n = 20). Subjective outcomes with the new Knee Society Score and clinical outcomes were evaluated. The functional activities, patient satisfaction and the knee flexion angle of the medial pivot group were significantly better than those of the non-medial pivot group. An intraoperative medial pivot pattern positively influences deep knee flexion and patient-reported outcomes.

Risk of Deep Venous Thrombosis in Drain Clamping With Tranexamic Acid and Carbazochrome Sodium Sulfonate Hydrate in Total Knee Arthroplasty

The aim of this randomized prospective study was to clarify risks associated with a drain-clamping method using tranexamic acid and carbazochrome sodium sulfonate hydrate after total knee arthroplasty (TKA). Subjects comprised 100 patients scheduled to undergo TKA, randomized into 2 groups: 50 patients received the drain-clamping method using tranexamic acid and carbazochrome sodium sulfonate hydrate and 50 patients received drain-clamping with saline. Although bleeding volume was significantly lower in the group with tranexamic acid and carbazochrome sodium sulfonate hydrate, risk of asymptomatic deep venous thrombosis as detected by ultrasonography was comparable between groups. Tranexamic acid and carbazochrome sodium sulfonate hydrate in the drain-clamping method help reduce bleeding after TKA without increasing the risk of deep venous thrombosis.

Posterior Femoral Condylar Offset After Total Knee Replacement in The Risk of Knee Flexion Contracture

The aim of this study was to clarify the risk of knee flexion contracture associated with a posterior femoral condylar offset after total knee replacement (TKR). Radiographs from 100 healthy Japanese volunteers were included in the study. We evaluated femoral component posterior offset in various implants and compared them with the normal Japanese knee. Posterior offset of the femoral condyle is up to a maximum of 4.7 times greater than that of the healthy Japanese knee in all knee implants. Excess posterior offset of the femoral condyle in TKR prostheses may cause knee joint flexion contracture due to the relative shortening of the posterior soft tissue.

Alterations of high‐mannose type N‐glycosylation in human and mouse osteoarthritis cartilage

OBJECTIVE The process of N-glycosylation is involved in the pathogenesis of various diseases. However, little is known about the contribution of changes in N-glycans in osteoarthritis (OA). The aim of this study was to identify the alterations in N-glycans in human OA cartilage, to characterize the messenger RNA (mRNA) expression of N-glycan biosynthesis enzyme genes (N-glycogenes) in mouse articular chondrocytes during cartilage degradation, and to analyze the relationship between altered N-glycan patterns and mechanisms of cartilage degradation. METHODS Alterations in N-glycans were analyzed in human OA cartilage and degraded mouse cartilage by high-performance liquid chromatography and mass spectrometry. N-glycogene mRNA expression in mouse chondrocytes was measured using reverse transcription-polymerase chain reaction. To assess the relationship between the altered N-glycans and degradation of mouse cartilage, experiments involving either knockdown or overexpression of N-glycogenes were performed in mouse articular chondrocytes. RESULTS Alterations in high-mannose type N-glycans were observed in both human OA cartilage and degraded mouse cartilage. The expression of β1,2N-acetylglucosaminyltransferase I (GlcNAc-TI) mRNA, which converts high-mannose type N-glycans, was significantly increased in degraded mouse cartilage. Mouse chondrocytes with suppressed GlcNAc-TI expression had reduced levels of matrix metalloproteinase 13 (MMP-13) and ADAMTS-5 (aggrecanase 2) mRNA following stimulation with interleukin-1α (IL-1α). In contrast, mouse chondrocytes overexpressing GlcNAc-TI had increased levels of MMP-13 and ADAMTS-5 mRNA following stimulation with IL-1α. CONCLUSION These findings indicate that alterations in high-mannose type N-glycans and N-glycogenes in chondrocytes correlate with the release of MMP-13 and ADAMTS-5 during cartilage degradation. These findings suggest that N-glycans play a crucial role in the initiation and progression of OA.

Embryonic Organ Culture

This unit provides detailed protocols for dissecting embryonic organs and performing organ culture to study questions in developmental biology. Procedures are described here for dissecting organs such as kidney, lung, and salivary gland. The unit also contains commentary including troubleshooting for embryonic organ culture. Curr. Protoc. Cell Biol. 41:19.8.1‐19.8.8.

Ganglioside GM3 has an essential role in the pathogenesis and progression of rheumatoid arthritis.

Rheumatoid arthritis (RA), a chronic systemic inflammatory disorder that principally attacks synovial joints, afflicts over 2 million people in the United States. Interleukin (IL)-17 is considered to be a master cytokine in chronic, destructive arthritis. Levels of the ganglioside GM3, one of the most primitive glycosphingolipids containing a sialic acid in the structure, are remarkably decreased in the synovium of patients with RA. Based on the increased cytokine secretions observed in in vitro experiments, GM3 might have an immunologic role. Here, to clarify the association between RA and GM3, we established a collagen-induced arthritis mouse model using the null mutation of the ganglioside GM3 synthase gene. GM3 deficiency exacerbated inflammatory arthritis in the mouse model of RA. In addition, disrupting GM3 induced T cell activation in vivo and promoted overproduction of the cytokines involved in RA. In contrast, the amount of the GM3 synthase gene transcript in the synovium was higher in patients with RA than in those with osteoarthritis. These findings indicate a crucial role for GM3 in the pathogenesis and progression of RA. Control of glycosphingolipids such as GM3 might therefore provide a novel therapeutic strategy for RA.

Effect of the Japanese herbal medicine, Boiogito, on the osteoarthritis of the knee with joint effusion.

BackgroundBoiogito (Japanese herbal medicine, Tsumura Co. Tokyo, Japan) contains sinomenin which inhibits inflammatory reactions. Since sinomenine is a principle component of the Boiogito, there is a possibility of it being effective on osteoarthritis (OA) of the knee with joint effusion. However, there is no report concerning the effectiveness of Boiogito on knee OA. The objective of the present study is to investigate the therapeutic effect of Boiogito on OA of the knee associated with joint effusion in a comparative study among randomly assigned groups.MethodsStudy was performed using 50 patients who were diagnosed with primary osteoarthritis of the knee with joint effusion. The patients were randomly assigned to two groups: one group (25 patients) using both loxoprofen (2-{4-[(2-oxocyclopentyl) methyl]} propanoic acid) and Boiogito and the other group (25 patients) using loxoprofen, and were evaluated during a 12 week observation period. The assessment parameters including knee scores in the Knee Society Rating System including Knee score and Functional scores, amount of joint effusion by joint puncture in clinically detected cases, the 36-items short form of the Medical Outcome Study Questionnaire (SF-36) as a measurement of health related quality of life were used.ResultsThe knee scores based on the Knee Society Rating System were improved in both groups. The staircase climbing up and down ability in the Knee society rating system functional score was significantly improved in the group using Boiogito and loxoprofen compared to the loxoprofen group. In the evaluation using SF-36, significant improvements were found in the scores in both groups in physical functioning after 12 weeks. The amount of joint fluid was significantly decreased at 4, 8 and 12 weeks compared to pre-administration baseline in the group using Boiogito and loxoprofen. A side effect of Boiogito, dry mouth, was found in one case. The symptom was mild and improved immediately after discontinuation of administration.ConclusionThe results indicated that Boiogito have a possibility for a treatment modality for joint effusion with osteoarthritis of the knee.

Interruption of Glycosphingolipid Synthesis Enhances Osteoarthritis Development in Mice

OBJECTIVE Glycosphingolipids (GSLs) are ubiquitous membrane components that modulate transmembrane signaling and mediate cell-to-cell and cell-to-matrix interactions. GSL expression is decreased in the articular cartilage of humans with osteoarthritis (OA). This study was undertaken to determine the functional role of GSLs in cartilage metabolism related to OA pathogenesis in mice. METHODS We generated mice with knockout of the chondrocyte-specific Ugcg gene, which encodes an initial enzyme of major GSL synthesis, using the Cre/loxP system (Col2-Ugcg(-/-) mice). In vivo OA and in vitro cartilage degradation models were used to evaluate the effect of GSLs on the cartilage degradation process. RESULTS Although Col2-Ugcg(-/-) mice developed and grew normally, OA changes in these mice were dramatically enhanced with aging, through the overexpression of matrix metalloproteinase 13 and chondrocyte apoptosis, compared to their wild-type (WT) littermates. Col2-Ugcg(-/-) mice showed more severe instability-induced pathologic OA in vivo and interleukin-1α (IL-1α)-induced cartilage degradation in vitro. IL-1α stimulation of chondrocytes from WT mice significantly increased Ugcg messenger RNA expression and up-regulated GSL metabolism. CONCLUSION Our results indicate that GSL deficiency in mouse chondrocytes enhances the development of OA. However, this deficiency does not affect the development and organization of cartilage tissue in mice at a young age. These findings indicate that GSLs maintain cartilage molecular metabolism and prevent disease progression, although GSLs are not essential for chondrogenesis of progenitor and stem cells and cartilage development in young mice. GSL metabolism in the cartilage is a potential target for developing a novel treatment for OA.

Depletion of gangliosides enhances cartilage degradation in mice

OBJECTIVE Glycosphingolipids (GSLs) are ubiquitous membrane components that play a functional role in maintaining chondrocyte homeostasis. We investigated the potential role of gangliosides, one of the major components of GSLs, in osteoarthritis (OA) pathogenesis. DESIGN Both age-associated and instability-induced OA models were generated using GM3 synthase knockout (GM3S(-/-)) mice. A cartilage degradation model and transiently GM3S-transfected chondrocytes were analyzed to evaluate the function of gangliosides in OA development. The amount of each series of GSLs in chondrocytes after IL-1α stimulation was profiled using mass spectrometry (MS). RESULTS OA changes in GM3S(-/-) mice were dramatically enhanced with aging compared to those in wild-type (WT) mice. GM3S(-/-) mice showed more severe instability-induced pathologic OA in vivo. Ganglioside deficiency also led to the induction of matrix metalloproteinase (MMP)-13 and ADAMTS-5 secretion and chondrocyte apoptosis in vitro. In contrast, transient GM3S transfection of chondrocytes suppressed MMP-13 and ADAMTS-5 expression after interleukin (IL)-1α stimulation. GSL profiling revealed the presence of abundant gangliosides in chondrocytes after IL-1α stimulation. CONCLUSION Gangliosides play a critical role in OA pathogenesis by regulating the expression of MMP-13 and ADAMTS-5 and chondrocyte apoptosis. Based on the obtained results, we propose that gangliosides are potential target molecules for the development of novel OA treatments.