Ichiro Sekiya

Ichiro Sekiya
Tokyo Medical and Dental University | TMDU · Center for Stem Cell and Regenerative Medicine

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366
Publications
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Introduction
Skills and Expertise

Publications

Publications (366)
Article
Cell therapy is a promising alternative treatment approach currently under study for osteoarthritis (OA), the most common chronic musculoskeletal disease. However, the mesenchymal stem cells (MSCs) used in cell therapy to treat OA are usually expanded in vitro to obtain sufficient numbers for transplantation, and their safety has not been fully ass...
Article
Full-text available
Background Osteoarthritis (OA) is an age-related joint disease characterized by progressive cartilage loss. Synovial mesenchymal stem cells (MSCs) are anticipated as a cell source for OA treatment; however, synovial MSC preparations isolated from OA patients contain many senescent cells that inhibit cartilage regeneration through their senescence-a...
Preprint
Background The possibility that mesenchymal stem cells (MSCs) can adhere to partial defects or degenerative areas in cartilage remains to be established. The purposes of this study were to clarify the proportion of MSCs that might adhere to degenerated cartilage, the time course for adhesion, and the morphological changes occurring during the adhes...
Article
Full-text available
Objectives Synovial mesenchymal stem cells (MSCs) have high freeze–thaw tolerance, whereas human umbilical vein endothelial cells (HUVECs) have low freezing tolerance. The differences in cell type-specific freeze–thaw tolerance and the mechanisms involved are unclear. This study thus aimed to identify the biological and physical factors involved in...
Article
Full-text available
Background Synovial mesenchymal stem cells (MSCs) have high proliferative potential and are considered an excellent source for stem cell therapy. Purposes To isolate MSCs from the synovium of ankle joints in patients with chronic lateral ankle instability (CLAI) and to compare the characteristics of MSCs derived from the synovium anterior to the t...
Article
Full-text available
Objectives IL1β enhances proliferation of synovial mesenchymal stem/stromal cells (synMSCs) although they don’t express its receptor, IL1R1/CD121a, on the cell surface. This study was aimed to elucidate the underlying mechanisms of IL1β-mediated growth promotion. Methods Human synMSCs were isolated from the suprapatellar synovial membrane. Cell pr...
Article
Full-text available
Knee osteoarthritis is a common degenerative joint disease characterized by chronic knee pain and disability in daily living. The lesion can involve the cartilage as well as the synovium, bone, ligaments, and meniscus, indicating a complicated pathology for knee osteoarthritis. The association with the meniscus has recently attracted much attention...
Article
Full-text available
Arthroscopic repair of the posterior horn of the lateral meniscus (LM) from an anterolateral portal has a risk of popliteal artery injury. Here, we present an ultrasound-assisted, arthroscopic, all-inside repair technique for a posterior LM tear to reduce the risk of neurovascular injury. An ultrasound probe covered with a sterile sleeve is placed...
Article
Full-text available
The positional relationship between cartilage defects and the meniscus is poorly understood for osteoarthritis of the knee. Our purpose was to clarify how cartilage defects extend and their association with the meniscus location during osteoarthritis progression. The subjects were women in their 70 s who were registered in the Kanagawa Knee Study....
Preprint
Background : Osteoarthritis (OA) is an age-related joint disease characterized by progressive cartilage loss. Synovial mesenchymal stem cells (MSCs) are anticipated as a cell source for OA treatment; however, synovial MSC preparations isolated from OA patients contain many senescent cells that inhibit cartilage regeneration through their senescence...
Article
Full-text available
Objective Synovial fibroblasts (SFs) in rheumatoid arthritis (RA) and osteoarthritis (OA) play biphasic roles in joint destruction and regeneration of bone/cartilage as mesenchymal stem cells (MSCs). Although MSCs contribute to joint homeostasis, such function is impaired in arthritic joints. We have identified functionally distinct three SF subset...
Article
Background: The presence of medial tibial osteophytes on knee radiographs suggests cartilage wear, but may be associated with medial meniscus extrusion (MME). The joint space width of the medial compartment consists anatomically of cartilage and the medial meniscus, but which is most responsible for joint space narrowing remains unclear. Magnetic...
Article
Objective The meniscus coverage ratio is an important factor in knee osteoarthritis. The ratio calculated by our software, which automatically segments meniscus and cartilage regions from knee MR images, correlates with cartilage measurements. However, the significance of the changes is questionable due to possible intermeasurement error during seq...
Article
The yield of primary synovial mesenchymal stromal cells (MSCs) from synovium of patients with rheumatoid arthritis (RA) is highly variable, but cell transplantation therapy with autologous synovial MSCs requires accurate prediction of the synovial MSC yield per synovium weight. Here, we determined whether the yield of synovial fluid MSCs might pred...
Chapter
Mesenchymal stromal cells (MSCs) isolated from the synovium are attractive because synovial MSCs have a high chondrogenic and proliferative potential. Periodic injections of synovial MSCs inhibited osteoarthritis (OA) progression and attenuated synovitis in a rat OA model. Most of the synovial MSCs injected into the knee joint migrated into the syn...
Article
Purpose The purpose of this study was to compare clinical outcomes between revision anterior cruciate ligament reconstruction (ACLR) using a bone-patellar tendon-bone (BPTB) autograft and that using a double-bundle hamstring tendon (HT) autograft. Methods Consecutive cases of revision ACLRs were reviewed. The Lysholm knee scale and Knee Osteoarthri...
Article
Full-text available
Purpose This study assessed the clinical outcomes of periprosthetic joint infection patients who underwent two-stage revision total knee arthroplasty with antibiotic-loaded cement spacers fabricated using a handmade silicone mold. Materials and methods This study included seven patients (average age 77 years, average follow-up time 54 months) who...
Article
Background Whether the distal femur and the proximal tibia have narrower aspect ratios in smaller knees has not been clarified. The purpose of this study was to confirm the dimensional characteristics of the distal femur and the proximal tibia using a novel method for consistently determining knee size. Methods A total of 220 Japanese osteoarthrit...
Article
Full-text available
Wrisberg variant discoid lateral meniscus (DLM) is a congenital anatomic variation of the meniscus in the knee joint, which is an uncommon type of the DLM. We present a surgical technique in a case of symptomatic Wrisberg variant DLM. To improve the instability due to the lack of the posterior attachment of meniscotibial ligament, the posterior por...
Preprint
Full-text available
Objective: Synovial fibroblasts (SF)s in rheumatoid arthritis (RA) and osteoarthritis (OA) play biphasic roles in joint destruction and regeneration of bone/cartilage as mesenchymal stem cells (MSC)s. Although MSCs contribute to joint homeostasis, such function is impaired in arthritic joints. We have identified functionally distinct three SF subse...
Article
Background: Simultaneous bilateral total knee arthroplasty is considered beneficial for patients with bilateral end-stage knee osteoarthritis, even though there could be potential postoperative complications. Presently, there is a paucity of evidence of the efficacy and safety of SB-TKA for elderly patients. This study aimed to compare the clinica...
Article
Full-text available
Background Drugs that can induce mesenchymal stem cell (MSC) mobilization from synovium into synovial fluid will enable regenerative medicine in joints without use of exogenous MSCs. An in vitro synovial MSC migration model had previously been developed for screening but had problems in practical application. We herein developed a novel in vitro mo...
Article
Full-text available
Objectives Radiographs are the most widespread imaging tool for diagnosing osteoarthritis (OA) of the knee. Our purpose was to determine which of the two factors, medial meniscus extrusion (MME) or cartilage thickness, had a greater effect on the difference in the minimum joint space width (mJSW) at the medial compartment between the extension ante...
Article
Full-text available
Background: Tissue engineering of cartilage requires the selection of an appropriate artificial scaffold. Polylactic acid (PLA) honeycomb films are expected to be highly biodegradable and cell adhesive due to their high porosity. The purpose of this study was to determine the optimal pore size of honeycomb PLA films for in vitro cartilage formatio...
Article
Full-text available
Background Mesenchymal stromal cell-derived extracellular vesicles (MSC-EVs) are promising candidates for tissue regeneration therapy. However, the therapeutic efficacy of MSC-EVs for meniscus regeneration is uncertain, and the mechanisms underlying MSC-EV-mediated tissue regeneration have not been fully elucidated. The aims of this study were to e...
Article
The study aimed to improve the long-term outcomes of open-wedge high tibial osteotomy (OWHTO); procedures combining OWHTO aimed at neutral alignment and arthroscopic centralization for meniscal extrusion have been introduced. The present study evaluated short-term patient-reported outcome measures; namely, the patient subjective satisfaction scores...
Article
Full-text available
Abstract Several studies have reported improvement in knee pain following mesenchymal stem cell (MSC) injections for knee osteoarthritis (OA). We developed a novel 3D magnetic resonance imaging (MRI) analysis software program that provides “projected cartilage area ratios” for automatic detection of changes in cartilage amounts. The primary objecti...
Article
Full-text available
Background Biological processes after anterior cruciate ligament reconstruction (ACLR) is crucial for recovery. However, alterations in the of synovial fluid cell population during the acute phase following ACLR and the relationship between these cells and postoperative pain is unclear. The goal of this study was to reveal alterations in synovial f...
Article
Background Normal knees generally show consistent femoral external rotation during knee flexion, although knees that have had total knee arthroplasty exhibit various rotational patterns with less rotational angle. This study aimed to determine whether consistent femoral external rotation during weight-bearing knee flexion after total knee arthropla...
Article
Full-text available
The recently developed arthroscopic centralization for lateral meniscal extrusion has obtained satisfactory short-term clinical and radiological results and improves the meniscus biomechanical properties. However, the effectiveness of treatment for meniscus extrusion after partial meniscectomy still requires elucidation. This study investigated the...
Article
Full-text available
Mesenchymal stem cells (MSCs) can show trisomy 7; however, the safety of these cells has not been fully investigated. The purposes of this study were to determine the ratio of patients whose synovial MSCs were transplanted clinically, to intensively investigate MSCs with trisomy 7 from a safety perspective, and to follow up the patients for 5 years...
Article
Background The purpose of this study was to compare arthroscopic findings of a degenerative flap and radial tear of the medial meniscus (MM) before and one year after treatment by meniscus repair and synovial mesenchymal stem cell (MSC) transplantation. Methods Patients with a degenerative flap and radial MM tear that would generally be treated by...
Article
Full-text available
Mesenchymal stem cell (MSC) therapy for cartilage or meniscus pathologies, including osteoarthritis, requires the easy and safe collection of MSC source materials. Synovial MSCs are attractive cell sources for joint pathology because of their high proliferative and chondrogenic potential in vitro and in vivo. We developed an ultrasound-guided harve...
Article
Full-text available
Intra-articular injections of mesenchymal stem cells (MSCs) can inhibit the progression of osteoarthritis (OA). Previous reports have used cultured MSCs, but the ability to use thawed cryopreserved MSC stocks would be highly advantageous. Our purpose was to elucidate whether thawed cryopreserved MSCs show comparable inhibitory effects on OA progres...
Article
Full-text available
Background We have developed a fully automatic three-dimensional MRI analysis software program for automatic segmentation of knee cartilage using a deep neural network. The purpose of this study was to use this software to clarify the interscan measurement error of the knee cartilage thickness and projected cartilage area ratio at 9 regions and 45...
Article
Full-text available
We have been studying mesenchymal stem cells (MSCs) in synovial fluid and the intra-articular injection of synovial MSCs in osteoarthritis (OA) knees. Here, mainly based on our own findings, we overview the characteristics of endogenous MSCs in the synovial fluid of OA knees and their mode of action when injected exogenously into OA knees. Many MSC...
Preprint
Full-text available
Background Drugs that can induce mesenchymal stem cell (MSC) mobilization from synovium into synovial fluid will enable regenerative medicine in joints without use of exogenous MSCs. An in vitro synovial MSC migration model had previously been developed for screening but had problems in practical application. We herein developed a novel in vitro mo...
Article
Full-text available
The load-distributing function is most critical in meniscal function, and meniscal extrusion suggests failure of this function, leading to the progression of osteoarthritis. The arthroscopic centralization technique has been developed to reduce meniscal extrusion; however, existing arthroscopic techniques sometimes fail to reduce the most extruded...
Article
Background Detailed kinematics of floor-sitting activities after total knee arthroplasty (TKA) have not been well explored. Knee kinematics of cross-legged sitting, seiza-sitting, and side-sitting after TKA were examined to clarify the differences in tibiofemoral kinematics of each activity. Methods Subjects were 40 knees in 20 osteoarthritic pati...
Article
Background The treatment of meniscus injuries combined with anterior cruciate ligament (ACL) reconstruction would be important to improve outcomes after ACL reconstruction. However, the effects of treatment methods for meniscus after ACL reconstruction have not been thoroughly investigated. The objective of this study was to investigate the effects...
Article
Full-text available
Background: Mesenchymal stem cells (MSCs) in synovial fluid increase after traumatic meniscus injuries. However, MSC kinetics in synovial fluid may differ for knees with degenerative meniscus injuries. Furthermore, the combination of surgical repair and synovial MSC transplantation has been found to improve clinical symptoms in patients with degen...
Article
Objective We have reported that fibrotic changes in infrapatellar fat pad (IFP) after acute joint inflammation are closely associated with persistent pain in rats. In this study, to examine the effects of anti-fibrotic treatment on persistent pain, we used C-type natriuretic peptides (CNP) at the recovery phase after acute joint inflammation. Desi...
Article
Full-text available
Background We developed a fully automatic three-dimensional knee MRI analysis software that can quantify meniscus extrusion and cartilage measurements, including the projected cartilage area ratio (PCAR), which represents the ratio of the subject’s actual cartilage area to their ideal cartilage area. We also collected 3D MRI knee data from 561 volu...
Article
Background: A high prevalence of osteoarthritis (OA) progression in patients with lateral meniscal defects has been reported. However, optimal management techniques for active patients remain ill-defined. Hypothesis: Meniscoplasty by capsular advancement with the application of the centralization technique would improve clinical and radiological...
Article
Augmentation of mesenchymal stem cells (MSCs) from the subacromial bursa in the setting of irreparable rotator cuff tears is a powerful candidate for future regenerative medicine. However, little is known about whether the preparation technique affects the individual differences and potentials of subacromial bursa-derived MSCs. The yields obtained...
Article
Full-text available
Background: Precise knowledge of the prevalence and trends of arthroplasty can facilitate the design of medical plans for efficient treatments. The National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB) Open Data Japan provides statistics about the annual number of arthroplasties (knee, hip, shoulder, finger, elbo...
Article
Full-text available
Stem cell therapy has potential for the treatment of degenerative meniscus injuries; however, an optimal animal model has not been established. Basic and clinical research show that synovial mesenchymal stem cells (MSCs) promote meniscus repair. The purposes of this study were to create a novel meniscus injury model in microminipigs and to investig...
Preprint
Full-text available
Background Intra-articular injections of mesenchymal stem cells (MSCs) can inhibit the progression of osteoarthritis (OA) in animal studies. Previous reports have used cultured MSCs, but the ability to use thawed cryopreserved MSC stocks would be highly advantageous. Our purpose was to elucidate whether thawed cryopreserved MSCs show comparable inh...
Article
Full-text available
Cell therapy is a promising treatment. One of the key aspects of cell processing products is ensuring sterility of cell-processing facilities (CPFs). The objective of this study was to assess the environmental risk factors inside and outside CPFs. We monitored the temperature, humidity, particle number, colony number of microorganisms, bacteria, fu...
Article
Background Mesenchymal stem cells (MSCs) transplantation therapy is considered an alternative therapy to prevent posttraumatic osteoarthritis (PTOA). However, consensus as to the sufficient number of MSCs for the prevention of PTOA is lacking. The purpose of this study was to determine the sufficient number of MSCs to achieve PTOA prevention and th...
Article
Optical coherence tomography (OCT) is an attractive tool for evaluating cartilage. We developed an OCT system that reconstruct and analyze a three‐dimensional (3D) OCT image by determining the cartilage surface and cartilage‐bone boundary from the image taken with currently available OCT devices. We examined the usefulness of 3D renderings of OCT i...
Preprint
Full-text available
Objective We have developed a fully automatic three-dimensional MRI analysis software that measures the projected cartilage area ratio (PCAR) to allow for the quantification of the cartilage in the knee. Our objectives were to verify our software’s accuracy for segmentation of cartilage and meniscus and to quantify cartilage and meniscus extrusion...
Preprint
Full-text available
Background: We developed a fully automatic three-dimensional knee MRI analysis software that can quantify meniscus extrusion and cartilage measurements, including the projected cartilage area ratio (PCAR), which represents the ratio of the subject’s actual cartilage area to their ideal cartilage area. We also collected 3D MRI knee data from 561 vol...
Preprint
Full-text available
Background We developed a fully automatic three-dimensional knee MRI analysis software that can quantify meniscus extrusion and cartilage measurements, including the projected cartilage area ratio (PCAR), which represents the ratio of the subject’s actual cartilage area to their ideal cartilage area. We also collected 3D MRI knee data from 561 volu...
Preprint
Full-text available
Background: Mesenchymal stem cells (MSCs) in synovial fluid increase after traumatic meniscus injuries. However, MSC kinetics in synovial fluid may differ for knees with degenerative meniscus injuries. Furthermore, the combination of surgical repair and synovial MSC transplantation has been found to improve clinical symptoms in patients with degene...
Article
Background Platelet-rich plasma (PRP) has emerged as a treatment for osteoarthritis (OA). However, the effect that leukocyte concentrations in PRP have on OA remains unclear. Purpose To clarify the optimal PRP formulation for OA treatment by comparing pure PRP, leukocyte-poor PRP (LP-PRP), and leukocyte-rich PRP (LR-PRP) in a rat arthritis model....
Preprint
Full-text available
Background Synovial mesenchymal stem cell (MSC) transplantation improved clinical outcomes in knees with cartilage defects and after repairs of degenerative torn menisci. For these, nucleated cells were cultured with 10% autologous serum for 14 days. Importantly, nucleated cell number and serum volume practically varied by patient, and initial cell...
Preprint
Full-text available
Objective We have developed a fully automatic three-dimensional MRI analysis software that measures the projected cartilage area ratio (PCAR) to allow for the quantification of the cartilage in the knee. Our objectives for this cross-sectional study were to verify our software’s accuracy and to quantify cartilage and meniscus extrusion. We also exa...
Article
PurposeAlthough several factors have been considered to be associated with pivot shift test grade in ACL injured patients, a conclusion regarding which factors contribute to the pivot shift test grade has not been reached. The purpose of this study was to identify factors associated with preoperative pivot shift test grade.Methods Three hundred and...
Preprint
Full-text available
Background Synovial mesenchymal stem cell (MSC) transplantation improved clinical outcomes in knees with cartilage defects and after repairs of degenerative torn menisci. For these, nucleated cells were cultured with 10% autologous serum for 14 days. Importantly, nucleated cell number and serum volume practically varied by patient, and initial cell...
Preprint
Full-text available
Purpose To improve long-term outcomes of open-wedge high tibial osteotomy (OWHTO), procedures combining OWHTO aimed at neutral alignment and arthroscopic centralization for meniscal extrusion have been introduced. The purpose of the present study was to compare short-term clinical and radiological outcomes of medial joint space width (JSW) after th...