Objective. To compare the properties of human mesenchymal stem cells (MSCs) isolated from bone marrow, synovium, periosteum, skeletal muscle, and adipose tissue.Methods. Human mesenchymal tissues were obtained from 8 donors during knee surgery for ligament injury. After collagenase digestion or gradient-density separation, nucleated cells were plated at an appropriate density for expansion at the maximum rate without colony-to-colony contact. Yield, expandability, differentiation potential, and epitope profile were compared among MSCs from the 5 different tissue sources.Results. Colony number per 10 3 nucleated cells was lower, and cell number per colony was higher, in bone marrow than in other mesenchymal tissues. When the cells were replated at low density every 14 days, bone marrow-, synovium-, and periosteum-derived cells retained their proliferation ability even at passage 10. In chondrogenesis studies in which the cells were pelleted and cultured in vitro, pellets from bone marrow-, synovium-, and periosteum-derived cells were shown to be larger and stained more extensively for cartilage matrix. Synovium-derived cells, in particular, had the greatest ability for chondrogenesis. In adipogenesis experiments, the frequency of oil red O-positive colonies was highest in synovium-and adipose tissue-derived cells. In studies of osteogenesis, the rate of alizarin red-positive colonies was highest in bone marrow-, synovium-, and periosteum-derived cells. For epitope profiling, 15 surface antigens were measured. Most appeared to have similar epitope profiles irrespective of cell source.Conclusion. Our findings indicate that there are significant differences in MSC properties according to tissue source, beyond donor and experimental variation. Superiority of synovium as a potential source of MSCs for clinical applications was demonstrated.

Although previous studies in the general population showed that hypomagnesemia is a risk for cardiovascular diseases (CVD), the impact of magnesium on the prognosis of patients on hemodialysis has been poorly investigated. To gain information on this we conducted a nationwide registry-based cohort study of 142,555 hemodialysis patients to determine whether hypomagnesemia is an independent risk for increased mortality in this population. Study outcomes were 1-year all-cause and cause-specific mortality with baseline serum magnesium levels categorized into sextiles. During follow-up, a total of 11,454 deaths occurred, of which 4774 had a CVD cause. In a fully adjusted model, there was a J-shaped association between serum magnesium and the odds ratio of all-cause mortality from the lowest to highest sextile, with significantly higher mortality in sextiles 1-3 and 6. Similar associations were found between magnesium and both CVD and non-CVD mortality. The proportion of patients with a baseline intact parathyroid hormone level under 50 pg/ml was significantly higher in the highest sextile; however, after excluding these patients, the CVD mortality risk in the highest sextile was attenuated. Thus, hypomagnesemia was significantly associated with an increased risk of mortality in hemodialysis patients. Interventional studies are needed to clarify whether magnesium supplementation is beneficial for improving patient prognosis.

Objective. Mesenchymal stem cells from synovium have a greater proliferation and chondrogenic potential than do those from bone marrow, periosteum, fat, and muscle. This study was undertaken to compare fibrous synovium and adipose synovium (components of the synovium with subsynovium) to determine which is a more suitable source for mesenchymal stem cells, especially for cartilage regeneration, and to examine the features of adipose synovium-derived cells, fibrous synovium-derived cells, and subcutaneous fat-derived cells to determine their similarities.Methods. Human fibrous synovium, adipose synovium, and subcutaneous fat were harvested from 4 young donors and 4 elderly donors. After digestion, the nucleated cells were plated at a density considered proper to expand at a maximum rate without colony-to-colony contact. The surface epitopes, proliferative capacity, cloning efficiency, and chondrogenic, osteogenic, and adipogenic differentiation potentials of the cells were compared.Results. Fibrous synovium-and adipose synovium-derived cells were higher in STRO-1 and CD106 and lower in CD10 compared with subcutaneous fat-derived cells. Cells derived from fibrous and adipose synovium had higher proliferative potential and colonyforming efficiency compared with subcutaneous fatderived cells, both in mixed-population and in singlecell-derived cultures. In chondrogenic assays, pellets from fibrous synovium-and adipose synovium-derived cells produced more cartilage matrix than did cell pellets from subcutaneous fat. Osteogenic ability was also higher in fibrous synovium-and adipose synovium-derived cells, whereas adipogenic potential was nearly indistinguishable among the 3 populations. Differentiation potential of the cells was similar between young and elderly donors.Conclusion. Cells derived from the fibrous synovium and from the adipose synovium demonstrate comparable chondrogenic potential. Adipose synoviumderived cells are more similar to fibrous synoviumderived cells than to subcutaneous fat-derived cells.

The findings of this study indicated that PDL cells possess crucial stem cell properties, such as self-renewal and multipotency, and express the mesenchymal stem cell markers CD105, CD166, and STRO-1 on their cell surface, although there were some variations. Thus, PDL cells can be used for periodontal regenerative procedures.

There are increasing reports that mesenchymal stem cells (MSCs) are present in various tissues other than bone marrow, including synovium. Here we investigated the optimal conditions for in vitro chondrogenesis of human synovium-derived MSCs and compared these cells with bone marrow-derived MSCs, especially in terms of their chondrogenesis potential. Synovium and bone marrow were harvested from six donors during knee operations for ligament injuries. Digested synovium cells or nucleated cells from bone marrow were expanded clonally. A pellet culture system was used for chondrogenesis, and the best combination of up to three cytokines of the seven assessed. Synovium-derived MSCs plated at a lower density expanded more rapidly. Contrary to previous reports, a combination of TGFbeta and dexamethasone was not sufficient to induce chondrogenesis. However, addition of BMP2 to TGFbeta and dexamethasone dramatically increased cartilage pellet size and the synthesis of cartilage matrix. The cartilage pellets were also analyzed by electron microscopy and immunohistology. DNA content per pellet decreased during chondrogenesis, indicating the pellet increased its size through the accumulation of newly synthesized extracellular matrix. Sequential chondrogenic gene expression was demonstrated by RT-PCR. Synovium-derived MSCs looked similar to the bone marrow-derived MSCs in their surface epitopes and proliferation potential; however, cartilage pellets from synovium were significantly larger than those from bone marrow in patient-matched comparisons. We demonstrated that the combination of TGFbeta, dexamethasone, and BMP2 was optimal for in vitro chondrogenesis of synovium-derived MSCs and that the synovium-derived MSCs have a greater chondrogenesis potential than bone marrow-derived MSCs.

Several reports describe that the explant culture of the trabecular bone after collagenase treatment produces mesenchymal stem cells (MSCs). However, the suspended cells had not been intensively examined concerning MSCs. We hypothesized that the cells would acquire the properties of MSCs during their expansion and therefore compared them with marrow aspiratederived MSCs. Human trabecular bones were washed, digested, filtered, and expanded clonally for 14 days. Their proliferation ability (n ‫؍‬ 9) and differentiation potentials for chondrocyte, adipocyte, and osteoblast (n ‫؍‬ 6) were similar with those of marrow aspirate-derived MSCs. Epitope and mRNA analysis revealed some differences in both types of cells, which disappeared with expansion and subcultivation. A mixed population of collagenase-released (CR) cells had similar differentiation potentials with CR clone, CD31 ؉ fraction, and osteoblastic cells. For quantitative study, trabecular bone and bone marrow were harvested by single aspiration using a biopsy needle (n ‫؍‬ 16). Although the total nucleated cell number harvested was similar, the colony-forming efficiency of CR cells was approximately 100-fold higher than that of BM cells and more than 1 million CR cells could be obtained in 14 days from all donors. Enzymatically released cells from trabecular bone became virtually identical to marrow aspirate-derived MSCs, demonstrating that a trabecular bone fragment can be an alternative source of MSCs. IntroductionHuman cells derived from trabecular bones have been used for many years in the study of bone cell biology. [1][2][3][4][5] Recently, Tuli et al, 6,7 Noth et al, 8 and Sottile et al 9 reported that human trabecular bone is a good source of mesenchymal stem cells (MSCs) with the characteristics of self-renewal and multilineage differentiation potential. To isolate MSCs from trabecular bones, they digested human trabecular bone with collagenase to release cells, referred to as collagenase-released (CR) cells. Then, they did explant cultures of the remaining bare bone fragments and harvested MSCs that were derived from the trabecular bones. CR cells were first mentioned by Robey and Termine as part of a study of osteoblast metabolism in vitro. 1 However, the CR cells were not examined intensively because the CR cell cultures showed a high level of type III collagen, which the researchers simply regarded as fibroblastic contamination. 1 Also, Noth et al described contamination by foreign marrow cells, especially fibroblasts, often predominated in the CR cell cultures. 8 Furthermore, collagenase pretreatment followed by extensive washing resulted in trabecular bone fragments completely devoid of surface-adherent cells, with all soft-tissue elements removed. 8 Therefore, until now the CR cells have been thought to be a poor source of MSCs.A large body of literature has developed on MSCs derived from bone marrow aspirate, 10 referred to as bone marrow (BM) cells here. Bone marrow is the tissue filling the space between vascular sinuses and bone surfaces...

SUMMARYIndole-3-acetic acid (IAA), an auxin plant hormone, is biosynthesized from tryptophan. The indole-3-pyruvic acid (IPyA) pathway, involving the tryptophan aminotransferase TAA1 and YUCCA (YUC) enzymes, was recently found to be a major IAA biosynthetic pathway in Arabidopsis. TAA1 catalyzes the conversion of tryptophan to IPyA, and YUC produces IAA from IPyA. Using a chemical biology approach with maize coleoptiles, we identified 5-(4-chlorophenyl)-4H-1,2,4-triazole-3-thiol (yucasin) as a potent inhibitor of IAA biosynthesis in YUC-expressing coleoptile tips. Enzymatic analysis of recombinant AtYUC1-His suggested that yucasin strongly inhibited YUC1-His activity against the substrate IPyA in a competitive manner. Phenotypic analysis of Arabidopsis YUC1 over-expression lines (35S::YUC1) demonstrated that yucasin acts in IAA biosynthesis catalyzed by YUC. In addition, 35S::YUC1 seedlings showed resistance to yucasin in terms of root growth. A loss-of-function mutant of TAA1, sav3-2, was hypersensitive to yucasin in terms of root growth and hypocotyl elongation of etiolated seedlings. Yucasin combined with the TAA1 inhibitor L-kynurenine acted additively in Arabidopsis seedlings, producing a phenotype similar to yucasin-treated sav3-2 seedlings, indicating the importance of IAA biosynthesis via the IPyA pathway in root growth and leaf vascular development. The present study showed that yucasin is a potent inhibitor of YUC enzymes that offers an effective tool for analyzing the contribution of IAA biosynthesis via the IPyA pathway to plant development and physiological processes.

OBJECTIVE There is now growing evidence that magnesium (Mg) deficiency is implicated in type 2 diabetes and its complications. However, it has not been fully elucidated whether hypomagnesemia is a predictor of end-stage renal disease (ESRD) in type 2 diabetic nephropathy. RESEARCH DESIGN AND METHODS This retrospective cohort study included 455 chronic kidney disease (CKD) patients (144 with type 2 diabetic nephropathy and 311 with nondiabetic CKD) who were hospitalized at Osaka General Medical Center for a CKD educational program between April 2001 and December 2007. The primary outcome was progression to renal replacement therapy. Participants were categorized based on serum Mg level into Low-Mg (serum Mg level ≤1.8 mg/dL) and High-Mg (serum Mg level >1.8 mg/dL) groups with the previously published normal lower limit chosen as the cutoff point. RESULTS Of the subjects with type 2 diabetic nephropathy, 102 progressed to ESRD during follow-up (median, 23 months). A multivariate Cox proportional hazards model showed that after adjustment for various demographic factors and laboratory data, the Low-Mg group had a 2.12-fold higher risk of ESRD than the High-Mg group (95% CI 1.28–3.51; P = 0.004). In contrast, 135 of the nondiabetic CKD subjects progressed to ESRD during follow-up (median, 44 months). No significant difference in outcome was found between the Low- and High-Mg groups of this population (adjusted hazard ratio, 1.15; 95% CI 0.70–1.90; P = 0.57). CONCLUSIONS Hypomagnesemia is a novel predictor of ESRD in patients with type 2 diabetic nephropathy.