Review of Caplan (1991) on cell-based therapeutic technology using Mesenchymal Stem Cells

This classic discusses the original 1991 publication 'Mesenchymal Stem Cells (MSCs)' by Dr. Caplan on the emergence of a new therapeutic technology of self-cell repair using MSCs. After the original classic publication, a large number of methods to regenerate injured tissue have been reported. Currently, MSCs are used clinically to repair articular cartilage defects, liver cirrhosis, cerebral infarction, spinal cord injury, graft-versus-host disease and others. As a result, MSCs are considered one of the most important cell sources for regenerative medicine. An MSC has been demonstrated to be a multipotent stem cell in cell culture and was thought to contribute to the regeneration of injured tissue at transplant sites, but recently, the concept of MSCs has changed such that they are now referred to as "medicinal signaling cells," owing to their often indirect effects on tissue repair and regeneration. Regardless of the name, either mesenchymal stem cells or medicinal signaling cells, MSCs will be used to regenerate injured tissue more widely in the near future.

Significantly earlier ambulation and reduced risk of near-falls with continuous infusion nerve blocks: a retrospective pilot study of adductor canal block compared to femoral nerve block in total knee arthroplasty

Background

Near-falls should be detected to prevent falls related to the earlier ambulation after Total knee arthroplasty (TKA). The quadriceps weakness with femoral nerve block (FNB) has led to a focus on adductor canal block (ACB). We purposed to examine the risk of falls and the earlier ambulation in each continuous infusion nerve block.

Methods

Continuous infusion nerve block (FNB or ACB) was performed until postoperative day (POD) 2 or 3. Pain levels and falls/near-falls with knee-buckling were monitored from POD 1 to POD 3. The score on the manual muscle test, MMT (0 to 5, 5 being normal), of the patients who could ambulate on POD 1, was investigated.

Results

A total of 73 TKA cases, 36 FNB and 37 ACB, met the inclusion criteria. No falls were noted. But episodes of near-falls with knee-buckling were witnessed in 14 (39%) cases in the FNB group and in 4 (11%) in the ACB group (p = 0.0068). In the ACB group, 81.1% of patients could ambulate with parallel bars on POD 1, while only 44.4% of FNB patients could do so (p = 0.0019). The quadriceps MMT values in the ACB group was 2.82, significantly higher than 1.97 in the FNB group (p = 0.0035). There were no significant differences in pain as measured with a numerical rating scale (NRS) and rescue analgesia through POD 3.

Conclusion

ACB was associated with significantly less knee-buckling and earlier ambulation post-TKA, with better quadriceps strength. Our study indicated the incidence of falls and near-falls with continuous infusion nerve blocks, and support the use of ACB to reduce the risk of falls after TKA. It is suggested that a certain number of the patients even with continuous ACB infusion should be considered with the effect of motor branch to prevent falls.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05735-6.

Transplantation of autologous bone marrow-derived mesenchymal stem cells under arthroscopic surgery with microfracture versus microfracture alone for articular cartilage lesions in the knee: A multicenter prospective randomized control clinical trial

Introduction

To investigate the efficacy of the transplantation of autologous bone marrow-derived mesenchymal stem cells (BMSCs) under arthroscopy with microfracture (MFX) compared with microfracture alone.

Methods

Eleven patients with a symptomatic articular cartilage defect of the knee were included in the study. They were randomized to receive BMSCs with MFX (cell-T group, n=7) or MFX alone (control group, n=4). Clinical results were evaluated using International Knee Documentation committee (IKDC) knee evaluation questionnaires and the Knee Injury and Osteoarthritis Outcome Score (KOOS) before and 48 weeks after surgery. Quantitative and qualitative assessments of repair tissue were carried out at 48 weeks by T2 mapping of magnetic resonance images (MRIs) and the magnetic resonance observation of cartilage repair tissue (MOCART) scoring system with follow-up MRI.

Results

No significant differences between preoperative and postoperative IKDC and KOOS were observed in the cell-T or control group. However, forty-eight weeks after surgery, the cell-T group showed a trend for a greater KOOS QOL score compared with the control group (79.4 vs. 39.1, respectively; P=0.07). The T2 value did not differ significantly between the two groups, but the mean MOCART score was significantly higher in the cell-T group than in the control group (P=0.02).

Conclusions

Compared with MFX alone, BMSC transplantation with MFX resulted in better postoperative healing of the cartilage and subchondral bone as determined by the MOCART score. Clinically, BMSC transplantation with MFX gave a higher KOOS QOL score after 48 weeks.

•

This is the first prospective randomized clinical trial between BMSCs with MFX and MFX alone.

•

BMSCs with MFX showed a trend for a greater KOOS QOL score compared with MFX alone.

•

BMSCs with MFX resulted in better healing of the cartilage by the MOCART score.

Irx3 and Bmp2 regulate mouse mesenchymal cell chondrogenic differentiation in both a Sox9-dependent and -independent manner

Sox9, a master regulator of cartilage development, controls the cell fate decision to differentiate from mesenchymal to chondrogenic cells. In addition, Sox9 regulates the proliferation and differentiation of chondrocytes, as well as the production of cartilage-specific proteoglycans. The existence of Sox9-independent mechanisms in cartilage development remains to be determined. Here, we attempted to identify genes involved in such putative mechanisms via microarray analysis using a mouse chondrogenic cell line, N1511. We first focused on transcription factors that exhibited upregulated expression following Bmp2 treatment, which was not altered by subsequent treatment with Sox9 siRNA. Among these, we selected positive regulators for chondrogenesis and identified Iroquois-related homeobox 3 (Irx3) as one of the candidate genes. Irx3 expression gradually increased with chondrocyte terminal differentiation in a reciprocal manner to Sox9 expression, and promoted the chondrogenic differentiation of mesenchymal cells upon Bmp2 treatment. Furthermore, Irx3 partially rescued impaired chondrogenesis by upregulating the expression of epiphycan and lumican under reduced Sox9 expression. Finally, Irx3 was shown to act in concert with Bmp2 signaling to activate the p38 MAPK pathway, which in turn stimulated Sox9 expression, as well as the expression of epiphycan and lumican in a Sox9-independent manner. These results indicate that Irx3 represents a novel chondrogenic factor of mesenchymal cells, acts synergistically with Bmp2-mediated signaling, and regulates chondrogenesis independent of the transcriptional machinery associated with Sox9-mediated regulation.

Effect of epigallocatechin-3-gallate on the increase in type II collagen accumulation in cartilage-like MSC sheets

With the aim to increase type II collagen content in the scaffold-free cartilage-like cell sheet using human bone marrow mesenchymal stem cells, we examined the effect of epigallocatechin-3-gallate (EGCG) addition to the chondrogenic medium for the cell sheet culture. The addition of EGCG (10 μM) increased the content of type II collagen 2-fold, while the addition did not markedly change the expression level of the genes encoding type II collagen and Sox 9. The reactive oxygen species level in the cells in cell sheets was thought to be too low to suppress the accumulation of type II collagen. On the other hand, the addition of EGCG markedly decreased both the matrix metalloproteinase-13 concentration in the supernatant of cell sheet culture and the type II collagen degradation activity in that supernatant. Taken together, EGCG may enhance the accumulation of type II collagen by suppressing type II collagen degradation.

Transplantation of Scaffold-Free Cartilage-Like Cell-Sheets Made from Human Bone Marrow Mesenchymal Stem Cells for Cartilage Repair: A Preclinical Study

OBJECTIVE

The object of this study was to determine culture conditions that create stable scaffold-free cartilage-like cell-sheets from human bone marrow-derived mesenchymal stem cells (hBMSCs) and to assess their effects after transplantation into osteochondral defects in nude rats.

DESIGN

(Experiment 1) The hBMSCs were harvested from 3 males, the proliferative and chondrogenic capacities were assessed at passage 1, and the cells were expanded in 3 different culture conditions: (1) 5% fetal bovine serum (FBS), (2) 10% FBS, and (3) 5% FBS with fibroblast growth factor 2 (FGF-2). The cells were harvested and made chondrogenic pellet culture. The cell proliferation rate, glycosaminoglycan/DNA ratio, and safranin-O staining intensity of pellets cultured condition 3 were higher than those of conditions 1 and 2. (Experiment 2) The hBMSCs were expanded and passaged 3 times under culture condition 3, and fabricate the cell-sheets in chondrogenic medium either with or without FBS. The cell-sheets fabricated with FBS maintained their size with flat edges. (Experiment 3) The cell-sheets were transplanted into osteochondral defects in nude rats. Histological analysis was performed at 2, 4, and 12 weeks after surgery.

RESULTS

The osteochondral repair was better after sheet transplantation than in the control group and significantly improved Wakitani score. Immunostaining with human-specific vimentin antibody showed that the transplanted cells became fewer and disappeared at 12 weeks.

CONCLUSIONS

These results indicate that culture with FGF-2 may help to quickly generate sufficient numbers of cells to create stable and reliable scaffold-free cartilage-like cell-sheets, which contribute to the regeneration of osteochondral defects.

Effect of epigallocatechin-3-o-gallate and quercetin on the cryopreservation of cartilage tissue

The effects of epigallocatechin-3-o-gallate (EGCG) and quercetin on the contents of extracellular matrix (ECM) in porcine cartilage at 4 °C were investigated. The addition of quercetin at 0.01 mM for the incubation of porcine cartilage disks at 4 °C for 2 week could suppress the decrease in ECM and the compliance of the disks, markedly greater than those of EGCG (1.0 mM).

Disparate response of articular- and auricular-derived chondrocytes to oxygen tension

PURPOSE/AIM

To determine the effect of reduced (5%) oxygen tension on chondrogenesis of auricular-derived chondrocytes. Currently, many cell and tissue culture experiments are performed at 20% oxygen with 5% carbon dioxide. Few cells in the body are subjected to this supra-physiological oxygen tension. Chondrocytes and their mesenchymal progenitors are widely reported to have greater chondrogenic expression when cultured at low, more physiological, oxygen tension (1-7%). Although generally accepted, there is still some controversy, and different culture methods, species, and outcome metrics cloud the field. These results are, however, articular chondrocyte biased and have not been reported for auricular-derived chondrocytes.

MATERIALS AND METHODS

Auricular and articular chondrocytes were isolated from skeletally mature New Zealand White rabbits, expanded in culture and differentiated in high density cultures with serum-free chondrogenic media. Cartilage tissue derived from aggregate cultures or from the tissue engineered sheets were assessed for biomechanical, glycosaminoglycan, collagen, collagen cross-links, and lysyl oxidase activity and expression.

RESULTS

Our studies show increased proliferation rates for both auricular and articular chondrocytes at low (5%) O2 versus standard (20%) O2. In our scaffold-free chondrogenic cultures, low O2 was found to increase articular chondrocyte accumulation of glycosaminoglycan, but not cross-linked type II collagen, or total collagen. Conversely, auricular chondrocytes accumulated less glycosaminoglycan, cross-linked type II collagen and total collagen under low oxygen tension.

CONCLUSIONS

This study highlights the dramatic difference in response to low O2 of chondrocytes isolated from different anatomical sites. Low O2 is beneficial for articular-derived chondrogenesis but detrimental for auricular-derived chondrogenesis.

Effects of agitation rate on aggregation during beads-to-beads subcultivation of microcarrier culture of human mesenchymal stem cells

With the aim to utilize human mesenchymal stem cells (hMSCs) grown in large scale for regenerative medicine, effects of agitation rate on aggregation during beads-to-beads subcultivation of microcarrier culture of hMSCs were studied. hMSCs could attach and grew on surface-type microcarriers of Cytodex 1, whereas almost no cell elongation and growth were observed on porous type microcarriers of Cytopores. The percentages of aggregated Cytodex 1 microcarriers at an agitation rate of 60 and 90 rpm were lower than that at 30 rpm, which was the lowest agitation rate necessary for the suspension of Cytodex 1 microcarriers, and the cells grew fastest at 60 rpm. hMSC could be subcultivated on Cytodex 1 by the beads-to-beads method at both 30 and 60 rpm without trypsinization. However, agitation at 60 rpm resulted in a markedly lower percentage of aggregated microcarriers not only before but also after subcultivation. The percentages of CD90- and CD166-positive cells among cells grown on Cytodex 1 at 60 rpm (91.5 and 87.6 %) were comparable to those of cells grown in the pre-culture on dishes. In conclusion, hMSCs could be subcultivated on Cytodex 1 by beads-to-beads method maintaining the expressions of the cell surface antigens CD90 and CD166, while adjusting agitation rate could decrease the microcarrier aggregation.

Synergistic effect of ascorbic acid and collagen addition on the increase in type 2 collagen accumulation in cartilage-like MSC sheet

Aiming to increase the content of type 2 collagen in scaffold-free cartilage-like cell sheets prepared using human bone marrow mesenchymal stem cells, the effect of several kinds of additives in a chondrogenic medium was investigated. Addition of ascorbic acid 2 phosphate (VCP) at a high concentration (250 µg/ml) and type 1 atelocollagen (5 µg/ml) increased the accumulation of type 2 collagen by fourfold and twofold, respectively. On the other hand, an antioxidant, glutathione showed no such effect. The synergistic effect of VCP and type 1 atelocollagen resulted in an eightfold increase in the accumulation level of type 2 collagen. Furthermore, the gene expression level of type 2 collagen increased and that of matrix metalloproteinase-13 (MMP-13) decreased to approximately one-third of the control. The increase in type 2 collagen accumulation in the scaffold-free cartilage-like cell sheet might be due to not only the enhancement of the synthesis but also the suppression of the degradation of type 2 collagen by MMP-13.

Cartilage Repair With Autologous Bone Marrow Mesenchymal Stem Cell Transplantation: Review of Preclinical and Clinical Studies

Clinical trials of various procedures, including bone marrow stimulation, mosaicplasty, and autologous chondrocyte implantation, have been explored to treat articular cartilage defects. However, all of them have some demerits. We focused on autologous culture-expanded bone marrow mesenchymal stem cells (BMSC), which can proliferate without losing their capacity for differentiation. First, we transplanted BMSC into the defective articular cartilage of rabbit and succeeded in regenerating osteochondral tissue. We then applied this transplantation in humans. Our previous reports showed that treatment with BMSC relieves the clinical symptoms of chondral defects in the knee and elbow joint. We investigated the efficacy of BMSC for osteoarthritic knee treated with high tibial osteotomy, by comparing 12 BMSC-transplanted patients with 12 cell-free patients. At 16-month follow-up, although the difference in clinical improvement between both groups was not significant, the arthroscopic and histological grading score was better in the cell-transplanted group. At the over 10-year follow-up, Hospital for Special Surgery knee scores improved to 76 and 73 in the BMSC-transplanted and cell-free groups, respectively, which were better than preoperative scores. Additionally, neither tumors nor infections were observed in all patients, and in the clinical study, we have never observed hypertrophy of repaired tissue, thereby guaranteeing the clinical safety of this therapy. Although we have never observed calcification above the tidemark in rabbit model and human histologically, the repair cartilage was not completely hyaline cartilage. To elucidate the optimum conditions for cell therapy, other stem cells, culture conditions, growth factors, and gene transfection methods should be explored.

Usefulness of urinary CTX-II and NTX-I in evaluating radiological knee osteoarthritis : the Matsudai knee osteoarthritis survey

BACKGROUND

To assess the usefulness of the urinary crosslinked C-telopeptide of type II collagen (uCTX-II) or crosslinked N-telopeptide of type I collagen (uNTX-I) for evaluating radiological knee osteoarthritis (OA), a cross-sectional study was conducted in the cohorts of the Matsudai knee osteoarthritis survey performed in Niigata, Japan.

METHODS

Urine specimens and standing knee AP X-rays were obtained from 1040 subjects who provided informed consent. The relationship between these markers and gender, age (patients aged 40-59 or 60-79 years), use of bisphosphonates, and OA grades (K-L classification) were analyzed. The diagnostic ability of uCTX-II to detect radiological knee OA was confirmed in the over 60-year-old subjects using a ROC curve.

RESULTS

The over 60-year-old men with OA grade 3,4 group had significantly higher uCTX-II levels than the other OA grade groups. In the over 60-year-old women, the uCTX-II levels significantly increased according to the progression of the knee OA grade. No significant difference was observed between the uNTX-I levels in the different OA grade groups. From the standpoint of biomarkers, the higher quartiles of the uCTX-II and uNTX-I levels gradually included higher numbers of grade ≥2 OA subjects in the over 60 year-old women. The area under the curve (AUC) in ROC analysis of uCTX-II exhibited a significant association with the diagnosis of knee OA in women (AUC 0.63), although the accuracy was evaluated to be low in the single measurement of our health checkup-based analysis.

CONCLUSIONS

This population-based study indicates that the uCTX-II level is strongly correlated with the knee OA grade in women over age 60. A further analysis is needed to clarify its predictive accuracy.

Systemic Administration of Granulocyte Colony-Stimulating Factor for Osteochondral Defect Repair in a Rat Experimental Model

OBJECTIVE

The objective of this study was to assess the effect of granulocyte colony-stimulating factor (G-CSF) on osteochondral defect repair in the rat knee.

DESIGN

Twenty-six 12-week-old male Lewis rats were randomly divided into 2 groups. From day 0 to day 4, the G-CSF group received glycosylated G-CSF, and the control group received phosphate-buffered saline. A 1.5-mm diameter and 1.0-mm deep osteochondral defect was introduced in the patellar groove of the bilateral femur in all rats on day 4. The peripheral blood nucleated cells were counted for 14 days from the first day of injection, the appearance of the cartilage repair was observed histologically and macroscopically for 2, 4, 8, 12, and 24 weeks after surgery.

RESULTS

The number of peripheral blood leukocytes increased 3 days and returned to normal levels 7 days after the first injection. Compared with the control group, the G-CSF group had more fibrous and/or bony tissue at earlier points in time. The tissue repair rate, which is defined as the percentage of repaired osteochondral defects, was significantly higher in the G-CSF group 4 weeks after surgery. However, there were no significant differences in the cartilage repair rate and the modified Wakitani score between the 2 groups at each time point.

CONCLUSIONS

The defect filling was significantly better in the G-CSF group in the early phases. Our findings suggest that G-CSF may promote the repair of osteochondral defects by mediating an increase in the number of peripheral blood nucleated cells.

[Cartilage repair and regenerative medicine ; past, present, and future]

Since the days of ancient Greece, it has been known that articular cartilage has poor potential to repair. In April, 2013, autologous chondrocyte implantation (ACI) was approved by the Japanese ministry of Health, Labour and Welfare, as the first orthopedic cell therapy in Japan. Half a century has passed since Chesterman's report on rabbit allogeneic chondrocyte implantation, and approximately 20 years since the first human ACI report by Brittberg. In Japan, 24 years has passed since Wakitani's allogeneic chondrocyte implantation, and over 10 years since the human ACI report by Ochi. A long-term follow-up clinical trial with the high statistical power is needed to verify the safety and efficacy of new cartilage joint therapy. Moreover, we need the infrastructure, including drug and/or device regulation and timely approved by the government, to apply new therapies in similar time frames to other developed nations.

Methods for producing scaffold-free engineered cartilage sheets from auricular and articular chondrocyte cell sources and attachment to porous tantalum

Scaffold-free cartilage engineering techniques may provide a simple alternative to traditional methods employing scaffolds. We previously reported auricular chondrocyte-derived constructs for use in an engineered trachea model; however, the construct generation methods were not reported in detail. In this study, methods for cartilage construct generation from auricular and articular cell sources are described in detail, and the resulting constructs are compared for use in a joint resurfacing model. Attachment of cartilage sheets to porous tantalum is also investigated as a potential vehicle for future attachment to subchondral bone. Large scaffold-free cartilage constructs were produced from culture-expanded chondrocytes from skeletally mature rabbits, and redifferentiated in a chemically-defined culture medium. Auricular constructs contained more glycosaminoglycan (39.6±12.7 vs. 9.7±1.9 μg/mg wet weight, mean and standard deviation) and collagen (2.7±0.45 vs. 1.1±0.2 μg/mg wet weight, mean and standard deviation) than articular constructs. Aggregate modulus was also higher for auricular constructs vs. articular constructs (0.23±0.07 vs. 0.12±0.03 MPa, mean and standard deviation). Attachment of constructs to porous tantalum was achieved by neocartilage ingrowth into tantalum pores. These results demonstrate that large scaffold-free neocartilage constructs can be produced from mature culture-expanded chondrocytes in a chemically-defined medium, and that these constructs can be attached to porous tantalum.

Are Kohn-Sham conductances accurate?

We use Fermi-liquid relations to address the accuracy of conductances calculated from the single-particle states of exact Kohn-Sham (KS) density functional theory. We demonstrate a systematic failure of this procedure for the calculation of the conductance, and show how it originates from the lack of renormalization in the KS spectral function. In certain limits this failure can lead to a large overestimation of the true conductance. We also show, however, that the KS conductances can be accurate for single-channel molecular junctions and systems where direct Coulomb interactions are strongly dominant.

Endoglin is involved in BMP-2-induced osteogenic differentiation of periodontal ligament cells through a pathway independent of Smad-1/5/8 phosphorylation

The periodontal ligament (PDL), a connective tissue located between the cementum of teeth and the alveolar bone of mandibula, plays a crucial role in the maintenance and regeneration of periodontal tissues. The PDL contains fibroblastic cells of a heterogeneous cell population, from which we have established several cell lines previously. To analyze characteristics unique for PDL at a molecular level, we performed cDNA microarray analysis of the PDL cells versus MC3T3-E1 osteoblastic cells. The analysis followed by validation by reverse transcription-polymerase chain reaction and immunochemical staining revealed that endoglin, which had been shown to associate with transforming growth factor (TGF)-beta and bone morphogenetic proteins (BMPs) as signaling modulators, was abundantly expressed in PDL cells but absent in osteoblastic cells. The knockdown of endoglin greatly suppressed the BMP-2-induced osteoblastic differentiation of PDL cells and subsequent mineralization. Interestingly, the endoglin knockdown did not alter the level of Smad-1/5/8 phosphorylation induced by BMP-2, while it suppressed the BMP-2-induced expression of Id1, a representative BMP-responsive gene. Therefore, it is conceivable that endoglin regulates the expression of BMP-2-responsive genes in PDL cells at some site downstream of Smad-1/5/8 phosphorylation. Alternatively, we found that Smad-2 as well as Smad-1/5/8 was phosphorylated by BMP-2 in the PDL cells, and that the BMP-2-induced Smad-2 phosphorylation was suppressed by the endoglin knockdown. These results, taken together, raise a possibility that PDL cells respond to BMP-2 via a unique signaling pathway dependent on endoglin, which is involved in the osteoblastic differentiation and mineralization of the cells.

Chondromodulin-1 directly suppresses growth of human cancer cells

Background

Chondromodulin-1 (ChM1), an endogenous anti-angiogenic factor expressed in cartilage, has been suggested to inhibit invasion of endothelial cells into cartilage. In addition, the ectopic administration of ChM1 has been reported to suppress tumorigenesis in vivo. However, it is unclear whether the anti-tumor effect is due to not only the anti-vascularization effect of ChM1, but also its direct action against oncocytes. In the present study, we sought to determine whether ChM1 has a direct action on tumor cells.

Methods

BrdU incorporation assay was performed on human umbilical vein endothelial cells (HUVECs), normal human dermal fibroblasts (NHDFs), HepG2 cells and HeLa cells in the presence or absence of recombinant human ChM1 (rhChM1). An adenovirus that expresses ChM1, Ad-ChM1, was established and applied to the tumor xenografted in vivo, and to in vitro tumor cells cultured on plates or in soft agar. Cell cycle-related proteins and the phosphorylation of Erk, Akt, and GSK3β, the downstream molecules of the extracellular matrix-integrin signaling pathways, in HepG2 cells treated with or without Ad-ChM1 were detected by western blot analysis. Luciferase reporter assays of STAT, GAS, and ISRE, which participate in another cytokine signaling pathway, ware performed in HepG2, HeLa, and HUVEC cells.

Results

ChM1 suppressed BrdU incorporation in HUVECs and in HepG2 cells dose-dependently, but did not suppress BrdU incorporation in NHDFs and HeLa cells cultured on plates. In soft agar, however, ChM1 suppressed the growth of HeLa cells, as well as HepG2 cells. Western blot analyses demonstrated that ChM1 decreased the levels of cyclin D1, cyclin D3, and cdk6 and increased those of p21^cip1 without affecting the phosphorylation levels of Erk, Akt, and GSK3β in HepG2 cells. The luciferase reporter assay demonstrated that ChM1 suppressed the transcriptional activities of STAT and GAS but not of ISRE.

Conclusion

ChM1 directly suppressed the proliferation of tumor cells in an anchorage-independent manner. However, ChM1 did not alter the phosphorylation of downstream molecules, at which the signaling pathways through growth factor and cytokine receptors converge with the anchorage-dependent pathway. Our results show that ChM1 has a direct anti-tumor effect; moreover, this effect occurs by inhibiting the STAT signaling pathway.

Relationship between radiological knee osteoarthritis and biochemical markers of cartilage and bone degradation (urine CTX-II and NTX-I): the Matsudai Knee Osteoarthritis Survey

Biochemical markers of cartilage and bone degradation are becoming increasingly important in the evaluation of knee osteoarthritis (OA). To clarify the correlation between radiological knee OA and urine CTX-II (C-terminal crosslinking telopeptide of collagen type II) or urine NTX-I (N-terminal crosslinking telopeptide of type I collagen), we conducted a cross-sectional study in the cohorts of the epidemiological knee survey at the Matsudai district in Niigata Prefecture, Japan. Urine specimens were collected from 296 subjects, and CTX-II and NTX-I were measured using ELISA. Standing knee AP X-rays were obtained and graded according to the Kellgren-Lawrence classification. The subjects were then divided by gender, age (40- to 59-year-old group and 60- to 79-year-old group), and the X-ray grade (Grade 0, 1, Grade 2, and Grade 3, 4). In non-OA (Grade 0, 1) subjects, the 60- to 79-year-old group had significantly higher CTX-II values than the younger group only in females. The subjects of both genders aged over 60 years of age with OA Grade 3, 4 had significantly higher CTX-II values than the Grade 0, 1 group or the Grade 2 group. For NTX-I, there were no significant differences between each OA grade although the Grade 3, 4 group females from 60 to 79 years of age had higher values than the Grade 2 group. In addition, in the 60- to 79-year-old subjects of both genders, a positive correlation was observed between the urine CTX-II and urine NTX-I. For the subjects ranging from 60 to 79 years of age in both genders, the urine CTX-II values indicate the progression of OA. In addition, the weak but positive correlation between urine CTX-II and urine NTX-I in the subjects ranging from 60 to 79 years of age in both genders suggests that bone resorption and cartilage degradation appear to develop in parallel.

PIASxbeta is a key regulator of osterix transcriptional activity and matrix mineralization in osteoblasts

We recently reported that tensile stress induces osteoblast differentiation and osteogenesis in the mouse calvarial suture in vitro. Using this experimental system, we identified PIASxbeta, a splice isoform of Pias2, as one of the genes most highly upregulated by tensile stress. Further study using cell culture revealed that this upregulation was transient and was accompanied by upregulation of other differentiation markers, including osterix, whereas expression of Runx2 was unaffected. Runx2 and osterix are the two master proteins controlling osteoblast differentiation, with Runx2 being upstream of osterix. Targeted knockdown of PIASxbeta by small interfering RNA (siRNA) markedly suppressed osteoblastic differentiation and matrix mineralization, whereas transient overexpression of PIASxbeta caused the exact opposite effects. Regardless of PIASxbeta expression level, Runx2 expression remained constant. Reporter assays demonstrated that osterix enhanced its own promoter activity, which was further stimulated by PIASxbeta but not by its sumoylation-defective mutant. NFATc1 and NFATc3 additionally increased osterix transcriptional activity when co-transfected with PIASxbeta. Because osterix has no consensus motif for sumoylation, other proteins are probably involved in the PIASxbeta-mediated activation and NFAT proteins may be among such targets. This study provides the first line of evidence that PIASxbeta is indispensable for osteoblast differentiation and matrix mineralization, and that this signaling molecule is located between Runx2 and osterix.

Osteoinduction with highly purified β-tricalcium phosphate in dog dorsal muscles and the proliferation of osteoclasts before heterotopic bone formation

The aim of the study was to examine the chronological histology of osteoinduction of highly purified beta-tricalcium phosphate (beta-TCP) implanted in dog dorsal muscles. Specimens were harvested on days 14, 28, 42, 56, 112 and 168 after implantation, and were analyzed by hematoxylin and eosin (HE) staining, tartrate-resistant acid phosphatase (TRAP) staining, immunohistochemistry, in situ hybridization, and silver impregnation. After day 28, abundant TRAP- and cathepsin K-positive multinucleated cells adhered to beta-TCP, suggesting that these cells are osteoclasts that can resorb beta-TCP. On day 56, new bone was formed and alpha1 chain of type I procollagen mRNA-positive osteoblasts lined the newly formed bone. Silver impregnation showed abundant collagen fibrils within the beta-TCP micropores. These results suggest that micropores function as a storage space for extracellular matrix components, including collagen. Newly formed bone never degenerated in the late stage, suggesting that beta-TCP has good biocompatibility and this material retains the conditions appropriate for osteointegration and bioresorption. In conclusion, beta-TCP has osteoinductivity after implantation in dog dorsal muscles without use of bone marrow cells or osteoinductive cytokines. The appearance of a large number of active osteoclasts precedes new bone formation.

Activating Gs a mutation rarely occurs in musculoskeletal tumors other than fibrous dysplasia

BACKGROUND

Activating Gs a mutations have been identified in most instances of fibrous dysplasia (FD). This mutation leads to consistently elevated intracellular cyclic adenosine monophosphate (cAMP) levels, with various biological consequences. The development of secondary sarcoma in FD is a rare but well-established phenomenon. This finding raised the possibility that a common gene mutation exists in these tumors.

MATERIALS AND METHODS

The expression of the Gs a mutation was examined in 16 cell lines and 173 musculoskeletal tumor tissues, including 13 cases of FD, via RT-PCR and sequence analysis.

RESULTS

No expression of a Gs a mutation was detected in any cell line or clinical tissue sample, excluding FD tissues. Direct sequence analysis demonstrated results identical to those of RT-PCR.

CONCLUSION

Activating Gs a mutation rarely occurs in musculoskeletal tumors other than FD. The occurrence of most sarcomas displays no correlation with Gs a mutations.

The acupuncture point and its connecting central pathway for producing acupuncture analgesia

Characteristics of the acupuncture point in producing acupuncture analgesia (AA) were examined by the inhibition of noxious responses in the brain stem reticular formation, potentials, and neuronal activity in the dorsal periaqueductal central gray (D-PAG), and analgesia caused by low frequency stimulation of the acupuncture point. As a result, stimulation of the muscle beneath the acupuncture point was found to be effective in producing AA. AA measured by tail flick, vocalization, and writhing tests was abolished by hypophysectomy, and by antiserum of beta-endorphin administered into the 3rd ventricle. The pathway from the D-PAG to the anterior hypothalamus (AA-AH) in the AA afferent pathway from the acupuncture point to the pituitary gland was determined. The lateral hypothalamus, lateral septum, cingulate bundle, dorsal-hippocampus, and habenulo-interpeduncular tract were found, in addition to regions previously found, to belong to the AA afferent pathway. A network of divergence and convergence in their rostral and caudal relations was observed. The AA afferent pathway diverges from the D-PAG, converges to the HP, and then projects to the AA-AH.

Inhibition of the analgesia inhibitory system by D-phenylalanine and proglumide

Stimulation of a nonacupuncture point (NAPS) does not normally produce analgesia in the same way that stimulation of an acupuncture point does. However, NAPS did produce dexamethasone reversible analgesia after intraperitoneal treatment with D-phenylalanine (DPA) or proglumide, or after microinjection of these compounds into such parts of the analgesia inhibitory system (AIS) as the lateral centromedian nucleus of the thalamus and part of the posterior hypothalamus. Inhibition of acupuncture analgesia (AA), or of morphine analgesia (MA) by 0.5 mg/kg, IP, which is equivalent to AA after AIS lesion, and of potentials in the lateral periaqueductal central gray evoked by repetitive NAPS or stimulation of the AIS, were antagonized by DPA. Disappearance of AA and MA in morphine tolerant acupuncture responder and nonresponder rats was reversed to reproduce the same magnitude of analgesia after proglumide application. The reproduced AA and MA were antagonized by dexamethasone. These results indicate that DPA and proglumide antagonized the AIS and unmasked the dexamethasone reversible AA and MA.

[An operated case of cervical spontaneous hematomyelia]

We have reported a case of cervical spontaneous hematomyelia caused by cavernous hemangioma. A 47-year-old woman experienced a sudden onset of pain in the neck on 5 December 1979. One week after the onset she began to have tetraparesis. There was a rapidly increasing weakness of the extremities and she was referred to our department on 25 December 1979. At the time, the positive neurological findings were flaccid tetraplegia, bilateral loss of all sensory perception below the C4 level and urinary retention. Chest x-ray films demonstrated an elevation of right diaphragma. Roentgenograms of the cervical spine were normal. Emergency myelography via cisternal puncture revealed a central filling defect at the level of C3-C5. But there was no displacement of dentate ligament on lateral view, suggesting an intramedullary mass lesion. Laminectomy from C2 to Th1 and evacuation of the intramedullary blood clot at C3-C5 level were performed successfully. Microscopic examination of clots revealed cavernous hemangioma. The postoperative course was uneventful and the patient gradually improved in her motility. In the review of the literature including our case, vascular malformations are the commonest cause of spontaneous hematomyelia. They are found 12 out of 18 cases (Table 1). The symptoms of spontaneous hematomyelia are characterized by sudden onset of pain and rapid development of long tract sign in a previously asymptomatic individual. Operated cases are summarized in table 2. Good operative results are obtained 6 out 9 cases. We will emphasize that in a case of spontaneous hematomyelia with acute progression of transverse myelopathy, early diagnosis and operation are extremely important, and for this purpose, myelography is considered to be one of the most useful examinations.