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T Koji

Publications and source records attributed to T Koji.

At least 19 recordsLinked to original sources
PubMed2001

Expression of fas/fas ligand (fasL) and its involvement in infiltrating lymphocytes in hepatocellular carcinoma (HCC).

BACKGROUND: This study was conducted to examine the expression of Fas/Fas ligand (FasL), to elucidate its relationship with tumor-infiltrating lymphocytes (TILs), and to detect possible gene mutation of Fas/FasL in patients with hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC). METHODS: Indirect immunohistochemical staining was performed on formalin-fixed, paraffin-embedded sections of liver biopsy and surgery specimens from five normal livers, and from the livers of 30 patients with HCC. Fas/FasL mRNA-expressing cells and apoptotic cells were detected by in situ hybridization and DNA nick end labeling (TUNEL), respectively. We also performed polymerase chain reaction (PCR)-amplifying and direct sequencing for the Fas/FasL gene. RESULTS: Fas/FasL and its mRNA were localized on the membrane or in the cytoplasm in some HCC cells, as well as hepatocytes. Their expression was enhanced in areas with infiltrating inflammatory cells in the noncancerous regions of liver tissue and on the margins of the cancerous tissue. The positivity rate for TUNEL was elevated along these margins. The labeling index of Fas/FasL was lower in the cancerous liver tissue than in the surrounding noncancerous region (P < 0.01), and tended to decrease in proportion to the malignancy of tumor cells; Fas/FasL expression was not found on poorly differentiated type cancer cells. Fas(-)/FasL(+), FasL-mRNA(+) HCC cells were seen in one specimen of moderately differentiated type. Some CD8+T lymphocytes were TUNEL-positive around the cancerous region. In this study, cancerous and noncancerous tissues in HCC revealed no genetic mutations in any exons of Fas/FasL. CONCLUSIONS: These findings suggest that Fas/FasL expression was decreased in proportion to the malignancy of tumor cells, and that infiltrating CD8+ T lymphocytes play a role in apoptosis in HCC. The apoptosis in HCC could be regulated by the suppression of Fas/FasL expression, or, sometimes, by the enhancement of FasL expression.

Aged↗
PubMed2001

Male germ cell death in mouse testes: possible involvement of Fas and Fas ligand.

Loss of germ cells is very common during various stages of mammalian spermatogenesis. Although cell death, particularly apoptosis, has been implicated, our understanding of the mechanisms underlying germ cell death is still limited. In order to elucidate the extent and mechanism of germ cell death, this review first covers what is known of germ cell degeneration in the normal testes of fetal, neonatal, and adult mice from electron microscopy (EM) and from terminal dUTP nick-end labeling (TUNEL) staining. The issue of whether the Fas and Fas ligand (FasL) system is involved in the induction of germ cell apoptosis in normal and damaged testes is then addressed, including consideration of both the ischemia-reperfusion model of testicular torsion and the estrogen-treated testis model of environmental endocrine disruption. Finally, this review proposes that different molecular pathways may be triggered to induce male germ cell apoptosis, depending upon the physiological and pathological states of the germ cells.

Animals↗
PubMed2001

Prolonged survival of rat cardiac allograft with proinflammatory cytokine inhibitor.

BACKGROUND: Proinflammatory cytokines, such as tumor necrosis factor (TNF-alpha) and interleukin-1 (IL-1), play important roles in acute allograft rejection. FR167653 is an inhibitor of these cytokines that acts through inhibition of the mitogen-activated protein kinase p38 pathway. We examined the effect of FR167653 on allograft rejection. METHODS: We used Brown-Norway and Lewis rats as donors and recipients, respectively. We performed heterotopic cardiac transplantation. The control group consisted of untreated rats. In the experimental groups, recipients were intraperitoneally injected with FR167653 just after operation, followed by daily injection of the drug from Day 1 to 10. We divided 20 rats into 5 groups, which received varying doses of FR167653, ranging from 75 to 300 mg/kg/day. RESULTS: In the control group, the mean graft survival was 6.8 +/- 0.3 days. FR167653 at 150 mg/kg/day significantly prolonged the survival period (up to 12.1 +/- 1.5 days, p = 0.002). Histologically, FR167653 markedly suppressed cellular infiltration on Day 5 post-transplantation. The serum level of TNF-alpha in the control group was persistently elevated from 9.3 +/- 3.9 pg/ml to 11.3 +/- 3.8 pg/ml, whereas FR167653 significantly suppressed the level to <1.4 +/- 1.4 pg/ml. CONCLUSIONS: FR167653 prolonged rat cardiac allograft survival by suppressing the action of proinflammatory cytokines.

Animals↗
PubMed2001

Fas/FasL mediated apoptosis of thyrocytes in Graves' disease.

We examined in the present study the possible involvement of Fas and its ligand (FasL) in the process of Graves' disease. Immunohistochemical analysis showed that few normal thyrocytes expressed Fas but many thyrocytes in Graves' disease expressed this molecule. The percentage of FasL-positive thyrocytes in Graves' thyroids was, however, less than in normal thyroids. Several apoptotic thyrocytes and infiltrating mononuclear cells (MNCs) were detected scattered throughout Graves' thyroid tissues and abundant proliferating cell nuclear antigen (PCNA)-positive thyrocytes were present. Apoptotic cells, as well as PCNA-positive cells, were scarcely detectable in normal thyroid glands, however. In vitro treatment of thyrocytes by IL-1beta a cytokine found to be expressed in Graves' thyroid glands, increased Fas but reduced FasL expression. IL-1beta-stimulated thyrocytes became sensitive to apoptosis by anti-Fas IgM monoclonal antibody (mAb). Activated T cells, which strongly expressed FasL, showed cytotoxic activity toward IL-1beta-stimulated thyrocytes but not toward unstimulated thyrocytes. This cytotoxic activity involved the Fas/FasL pathway. Importantly, unstimulated thyrocytes could kill activated, but not resting, T cells. IL-1beta-stimulated thyrocytes, with down-regulated FasL expression, could not efficiently kill activated T cells. The cytotoxic activity of unstimulated thyrocytes toward activated T cells was inhibited by anti-FasL mAb. Interestingly, unstimulated thyrocytes induced apoptosis in IL-1beta-stimulated thyrocytes but not in unstimulated thyrocytes. These interactions were also blocked by anti-FasL mAb. Our results suggest that the apoptotic cell death of both thyrocytes and infiltrating MNCs found in Graves' thyroid glands is regulated by IL-1beta through Fas/FasL interactions.

Apoptosis↗
PubMed2001

Partial tolerance of subcutaneously transplanted xenogeneic tumour cell graft by Fas-mediated immunosuppression.

Certain anti-Fas antibodies, such as RMF2, induce apoptosis of Fas-expressing cells. We applied the Fas/anti-Fas system to induce killing of Fas-expressing immunocytes with resultant immunosuppression. W7TM-1 tumour cells, a rat T-cell line, were inoculated subcutaneously in BALB/c mice and tumour growth was monitored in untreated mice and in mice treated with RMF2. Prior to treatment with RMF2, we examined the expression of Fas in isolated splenocytes and in tumour-infiltrating lymphocytes by flow cytometry and immunohistochemistry, respectively. There was a remarkable increase in Fas-positive lymphocytes, including natural killer (NK) cells, among splenocytes at day 5 after tumour cell inoculation. The number of Fas-positive infiltrating lymphocytes also increased markedly, from day 5 to day 10. We then examined whether RMF2 could induce apoptosis of Fas-positive activated lymphocytes isolated from the spleen at day 5 in vitro. Terminal deoxy (d) -UTP nick end labelling (TUNEL) and Annexin V staining methods showed apoptosis of isolated cells when incubated with RMF2, and typical apoptotic features were confirmed by 4',6-diamidino-2-phenylindole dihydrochloride (DAPI) staining. Furthermore, suppression of cellular and humoral immunity was noted in RMF2-treated mice by mixed lymphocyte reaction and assay of serum levels of immunoglobulin G, respectively. Finally, treatment of animals with RMF2 daily from day 5 to day 9 could maintain the tumour size, while the tumour mass began to diminish in untreated mice immediately after reaching a maximum size. We confirmed the enhancing effects of long-term treatment with RMF2, through the induction of immunosuppression, on the growth of unvascularized xenogeneic tumour cell grafts.

Animals↗
PubMed2001

Enhanced expression of complement C5a receptor mRNA in human diseased kidney assessed by in situ hybridization.

BACKGROUND: Anaphylatoxin C5a mediates inflammatory responses through interaction with a specific C5a receptor (C5aR), the expression of which is thought to be restricted to peripheral blood leukocytes. Although the presence of C5aR on cultured mesangial cells and tubular epithelial cells has recently been documented, the tissue distribution of C5aR in diseased kidney has not yet been determined. METHODS: Immunohistochemistry and nonradioactive in situ hybridization for C5aR were performed in 34 tissue samples of kidneys from patients with various renal diseases, including 4 with minimal change nephrotic syndrome (MCNS), 5 with membranous nephropathy (MN), and 25 with mesangial proliferative glomerulonephritis (mesGN; 15 patients with IgA nephropathy, 5 with non-IgA mesGN, and 5 with lupus nephritis). Normal portions of surgically resected kidney served as the control. RESULTS: In normal kidneys, C5aR protein was detected in tubular epithelial cells, while C5aR mRNA was detected in a few glomerular cells, tubular epithelial cells, and vascular endothelial and smooth muscle cells. In MCNS, the distribution of C5aR protein and mRNA was similar to that in normal kidneys. In MN and mesGN, C5aR protein and mRNA were detected in mesangial cells, glomerular epithelial and endothelial cells, Bowman's capsule cells, tubular cells, infiltrating cells, and vascular endothelial and smooth muscle cells. The glomerular expression of C5aR mRNA and protein correlated positively with the degree of mesangial hypercellularity and mesangial matrix expansion in mesGN. In the tubulointerstitium, interstitial expression of C5aR mRNA correlated positively with the degree of tubular atrophy and interstitial broadening in mesGN. Furthermore, the interstitial expression of C5aR mRNA correlated positively with the level of serum creatinine. CONCLUSIONS: Our results indicate that renal cells produce C5aR and that activation of C5a/C5aR pathway on renal cells may be involved in tissue injury in mesGN.

Adolescent↗
PubMed2001

Expression of Fas and Fas ligand in normal and ischemia-reperfusion testes: involvement of the Fas system in the induction of germ cell apoptosis in the damaged mouse testis.

Apoptosis of germ cells is very common in normal and injured mammalian testes. The aim of this study was to examine the possible involvement of the Fas and Fas ligand (FasL) system in the induction of germ cell apoptosis in normal and ischemia-reperfusion testes of adult mice. Apoptosis was assessed by the TUNEL method and by DNA gel electrophoresis. Fas and FasL mRNAs were detected by Northern blotting and reverse transcription polymerase chain reaction techniques, and proteins were analyzed by Western blotting and immunohistochemistry. Apoptosis of germ cells was identified in the normal testis especially around stages XI and XII, whereas the expression of Fas and FasL was largely confined to Leydig cells and Sertoli cells, respectively. However, in the testes reperfused after 1 h of ischemia, a high number of TUNEL-positive cells were identified in parallel with increased Fas-positive germ cells, whereas FasL expression in Sertoli cells was almost constant irrespective of the duration of reperfusion. Moreover, i.p. injection of anti-Fas antibody, which blocks the interaction between Fas and FasL, inhibited apoptosis, as indicated by the reduced number of TUNEL-positive cells, except for apoptosis at stages XI and XII. Our results indicate that the Fas/FasL system mediates apoptosis of spermatogenic cells in the injured testis but not spontaneous apoptosis in the normal testis.

Animals↗
PubMed2001

Doxorubicin-induced DNA intercalation and scavenging by nuclear glutathione S-transferase pi.

Glutathione S-transferase (GST) functions in xenobiotic biotransformation and drug metabolism. Increased expression of GSTpi, an isozyme of GST, has been found in cancer cells resistant to doxorubicin hydrochloride (DOX) or cis-diamminedichloroplatinum (II) (CDDP), and this increase was believed to be correlated with drug resistance of cancer cells. GST is mainly expressed in the cytoplasm; GSTpi in the nucleus has been reported in cancer cells, but the meaning of this result is not known. Here, we studied changes in the amount of nuclear GSTpi after exposure of cancer cells to anticancer drugs, and role of the nuclear GSTpi in drug resistance. We found nuclear GSTpi in cancer cells resistant to DOX, and the amount of nuclear GSTpi was enhanced by treatment of the cancer cells with DOX or CDDP. We also found that a mushroom lectin, an inhibitor of nuclear transport, inhibited the nuclear transfer of GSTpi, suggesting the existence of a specific transport system for the nuclear transfer of GSTpi. Nuclear GSTpi protected DNA against damage by anticancer drugs. These results suggest a possible role of GSTpi in the acquisition of resistance to anticancer drugs by cancer cells.

Antineoplastic Agents↗
PubMed2001

Importance of NF-kappaB in rheumatoid synovial tissues: in situ NF-kappaB expression and in vitro study using cultured synovial cells.

OBJECTIVES: To examine whether inhibition of NF-kappaB induces apoptosis of human synovial cells stimulated by tumour necrosis factor alpha (TNFalpha), interleukin 1beta (IL1beta), and anti-Fas monoclonal antibody (mAb). METHODS: The expression of proliferating cell nuclear antigen (PCNA), NF-kappaB, and the presence of apoptotic synovial cells were determined in synovial tissues. Apoptosis of cultured synovial cells was induced by inhibition of NF-kappaB nuclear translocation by Z-Leu-Leu-Leu-aldehyde (LLL-CHO). The activation of caspase-3 and expression of XIAP and cIAP2 in synovial cells in LLL-CHO induced apoptosis was also examined. RESULTS: Abundant PCNA+ synovial cells were found in rheumatoid arthritis (RA) synovial tissue, though a few apoptotic synovial cells were also detected in the RA synovial tissues. Nuclear NF-kappaB was expressed in RA synovial cells. Electrophoretic mobility shift assay showed that treatment of cells with TNFalpha or IL1beta significantly stimulated nuclear NF-kappaB activity. A small number of apoptotic synovial cells expressing intracellular active caspase-3 were found after treatment of cells with LLL-CHO. Although treatment of RA synovial cells with TNFalpha or IL1beta alone did not induce apoptosis, apoptosis induced by LLL-CHO and caspase-3 activation were clearly enhanced in TNFalpha or IL1beta stimulated synovial cells compared with unstimulated synovial cells. Furthermore, induction of apoptosis of synovial cells with caspase-3 activation by anti-Fas mAb was clearly increased by LLL-CHO. The expression of cIAP2 and XIAP in synovial cells may not directly influence the sensitivity of synovial cells to apoptosis induced by LLL-CHO. CONCLUSION: The results suggest that NF-kappaB inhibition may be a potentially important therapeutic approach for RA by correcting the imbalance between apoptosis and proliferation of synovial cells in RA synovial tissue.

Antibodies, Monoclonal↗
PubMed2001

Intraglomerular synthesis of complement C3 and its activation products in IgA nephropathy.

BACKGROUND: Complement activation is thought to be pathologically important in IgA nephropathy (IgAN). Although C3 deposition in the mesangium is found in IgAN, the origin of C3 is not clear. We recently demonstrated intraglomerular C3 synthesis in the human kidney; however, the activation and pathological role of locally synthesized C3 remains unclear. Here we performed nonradioactive in situ hybridization for C3 mRNA and immunohistochemistry for C3 and its activation products, such as C3d and membrane attack complex (MAC), to determine whether locally produced C3 in glomeruli was activated in IgA nephropathy. METHODS: Renal samples from 14 patients with IgAN and 5 with minimal change nephrotic syndrome (MCNS) were examined. Uninvolved portions of surgically removed kidneys with tumors served as normal controls. RESULTS: C3 mRNA was not detected in glomeruli in control tissue and MCNS, but was strongly expressed in resident glomerular cells of IgAN, including mesangial cells, glomerular epithelial cells and the cells of Bowman's capsule. Examination of serial sections disclosed that more than 70% of cells positive for C3 mRNA were also stained for C3 protein, C3d, and MAC. Double staining for in situ hybridization and immunohistochemistry also revealed that those C3 mRNA signals were present in intraglomerular cells positive for C3. The expression of C3 mRNA and MAC in glomeruli correlated significantly with the degree of mesangial matrix expansion. CONCLUSIONS: Our results demonstrated that locally synthesized C3 is activated in the glomeruli of IgAN and that its expression correlated with the severity of mesangial matrix expansion. These findings suggest that activation of C3 may be involved in tissue injury in IgAN through the formation of membrane attack complex.

Adolescent↗
PubMed2001

Expression of metallothionein in colorectal cancers and synchronous liver metastases.

The aim of this study is to clarify whether the expression of metallothionein (MT) is related with the malignant potential in primary colorectal cancer and/or synchronous liver metastasis. Immunohistochemical staining for MT was performed on the specimens of adenocarcinoma of the colon and rectum and its liver metastases in 34 patients treated with curative surgery, respectively. Expression of MT was compared with clinicopathological variables and patient survival. In patients with primary colorectal cancer, positive expression was found in 7 of 34 (20.6%) patients, but MT was not detected in any of the cases of liver metastases (0%; p = 0.0111). In the primary tumor, positive MT expression was significantly associated with a higher degree of lymph node involvement (mean +/- SD: 48.4 +/- 33.8 vs. 18.6 +/- 24.4% in MT-positive and MT-negative tumors, respectively; p = 0.0122). The survival rate in the patients with MT-negative tumors was significantly better than that in those with MT-positive tumors as primary sites (p = 0.0198). MT expression in colorectal cancer may be a potential marker affecting lymph node metastases and may be a predictor of a poor prognosis, particularly in patients with synchronous liver metastases.

Adenocarcinoma↗
PubMed2001

Antimicrobial susceptibility of Staphylococcus intermedius isolated from healthy and diseased dogs.

A total of 90 strains of Staphylococcus intermedius isolated from dogs were examined for antimicrobial susceptibility. There were no significant differences in the distribution patterns of MICs between strains from 1982 to 1985 and those from 1999, and between strains from healthy dogs and those from diseased dogs. All of the strains were susceptible to ABPC, DMPPC, CEX, TDM, ERFX, BFLX, and FF at concentrations of 0.05 to 6.25 microg/ml. The MICs of OTC, KM, EM, AIV-TS, and LCM were distributed in a broad range of 0.1 to >100 microg/ml, indicating the existence of resistant as well as susceptible populations of S. intermedius. Thirty-three strains (36.7%) were resistant to one or more anitmicrobial agents such as OTC (n=32), KM (n=9), EM (n=7), AIV-TS (n=7), and LCM (n=7).

Animals↗
PubMed2001

Localization in situ of specific RNA by electron microscopy.

To better understand the metabolism of RNA in nuclei, the analysis of precise nuclear distribution of specific RNA would be essential. For this purpose, nonradioactive electron microscopic (EM) in situ hybridization may be the most appropriate technique while the details required for the technique have not been fully established. In the present study, we attempted to localize 28S and 18S rRNAs in the nuclei of mouse Sertoli cells by EM in situ hybridization as a model system. After various preliminary experiments we chose the pre-embedding method; fresh-frozen sections of mouse testis were fixed with a mixture of 4% paraformaldehyde and 0.1% glutaraldehyde, digested with 10 microg/ml of proteinase K and hybridized with thymine-thymine (T-T) dimerized oligodeoxynucleotides (oligo-DNA) complementary to a part of 28S and 18S rRNAs. Then, the T-T dimers were detected enzyme-immunohistochemically with horseradish peroxidase (HRP) labeled anti-T-T dimer. After osmification of HRP products, the sections were embedded in Epon resin, cut into 100 nm ultra-thin sections and observed under a transmission electron microscope. As a result, we successfully localized both 28S and 18S rRNAs in the dense fibrillar and granular components of the nucleolus, showing the usefulness of nonradioactive EM in situ hybridization in the nuclear localization of specific RNA.

Animals↗
PubMed2000

Eradication of breast cancer xenografts by hyperthermic suicide gene therapy under the control of the heat shock protein promoter.

To investigate the usefulness of heat shock protein (HSP) promoter for breast cancer gene therapy, hyperthermia and HSV thymidine kinase (tk) suicide gene combination therapy was examined with mouse mammary cancer cell line FM3A. HSP promoter activity was markedly increased after heat shock (41-45 degrees C), with maximum activation (about 400-fold) at 3 hr. An in vitro cytotoxic assay showed that HSP-tk-transduced FM3A cells became more sensitive (more than 50,000 times) to ganciclovir (GCV) with heat shock, but untreated cells showed no increased cytotoxic sensitivity to GCV compared with control FM3A cells. In addition to promoter-oriented selective cell killing, a "chemosensitization effect" as a bystander effect was demonstrated by hyperthermia and suicide gene combination therapy, using a non-heat-inducible promoter. Immunohistochemical analysis revealed that this synergistic killing effect was dependent on apoptotic cell death with upregulation of both Fas and FasL (Fas ligand) expression. We also examined the efficacy of HSP-tk gene therapy in vivo by implanting breast cancer in subcutaneous and intraperitoneal models of BALB/c nude mice targeted by the HVJ-anionic liposome method. Significant tumor regression was observed in HSP-tk-transduced tumors followed by hyperthermia therapy, but no such inhibition was noted in either the mock vector transfection or hyperthermia group compared with control tumor-bearing mice. Our results demonstrate that this combination system is synergistically effective in mediating Fas-dependent apoptosis for a specific gene therapy targeting HSP-expressing mammary carcinomas, even in advanced and heat-resistant breast cancer.

Animals↗
PubMed2000

Enhanced cell death in NR-S1 tumor by photodynamic therapy: possible involvement of Fas and Fas ligand system.

BACKGROUND AND OBJECTIVES: To investigate the effect of photodynamic therapy (PDT) on cell death in malignant tumor tissue, the frequency of terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL)-positive cells and the possible involvement of Fas and Fas ligand system were evaluated. STUDY DESIGN/MATERIALS AND METHODS: NR-S1 tumor-bearing C3H/HeNCrj mice were treated by PDT with Photofrin(R) (12 mg/kg body weight) and Nd:YAG dye laser (630 nm, 10 Hz, 150 J/cm(2)). Paraffin-embedded tissue sections from the excised tumor tissues at 6, 12, 24, 48 hours after PDT were analyzed by TUNEL for the occurrence of apoptosis and by immunohistochemistry for Fas and Fas ligand (FasL) expression. TUNEL-positive cells as well as Fas- or FasL-positive cells were counted and expressed as a percentage of positive cells per total cells. RESULTS: Based on the percent area of tumor necrotic foci, the most effective conditions for PDT were first determined. Under these conditions, PDT increased the number of TUNEL-positive tumor cells at 12 hours after irradiation. In parallel with the increase in TUNEL-positive cells, Fas-positive tumor cells were also found in the same area where many TUNEL-positive tumor cells were found. The expression of Fas ligand was found in the tumor cells surrounding TUNEL-positive cells on serial sections. A significant increase in FasL-positive lymphocytes was observed at 12 hours, whereas the infiltration of such lymphocytes into the area where TUNEL-positive tumor cells were observed was rare. CONCLUSION: The possible role of Fas/FasL system in the cell death induced by PDT with Photofrin(R) and Nd:YAG dye laser was suggested. Moreover, the role of infiltrated lymphocytes seemed not to be so much in this model.

Animals↗
PubMed2000

Assessment of decalcifying protocols for detection of specific RNA by non-radioactive in situ hybridization in calcified tissues.

For the best performance of in situ analysis of specific RNA expression in calcified tissues, it is necessary to choose an appropriate protocol to decalcify the tissues. We evaluated the usefulness of various acid-based decalcifying reagents with reference to 28 S rRNA staining by in situ hybridization using a thymine-thymine dimerized oligonucleotide probe. The reagents evaluated were 10% nitric acid, 10% HCl, 5% formic acid, 5% trichloroacetic acid, Morse's solution, Plank-Rychlo's solution, and K-CX solution, all of which are commonly used to decalcify tissues, and their effects on retention of morphology and RNA were compared with EDTA-based solutions. When normal mouse mandible was used as a model tissue, well-preserved morphology of ameloblasts was obtained from sections decalcified with Morse's solution, 10% HCl, Plank-Rychlo's solution, and K-CX solution, and best retention of 28 S rRNA was obtained with 5% formic acid and Morse's solution. We recommend Morse's solution to decalcify tissues to be processed for the rapid analysis of specific RNA expression. Indeed, we detected specific mRNAs strongly in sections treated with Morse's solution, and quantitative analysis showed that the ratio of signal intensities of 28 S rRNA and the specific mRNAs correlated with each other depending on decalcifying solutions.

Animals↗
PubMed2000

Apoptosis of articular chondrocytes in rheumatoid arthritis and osteoarthritis: correlation of apoptosis with degree of cartilage destruction and expression of apoptosis-related proteins of p53 and c-myc.

To investigate the relationship of chondrocyte apoptosis and cartilage destruction, we performed in situ nick end labeling (ISNEL), electron microscopy, and immunohistochemistry against apoptosis-related proteins, p53 and c-myc, in the articular cartilages of patients with rheumatoid arthritis (RA; n = 12) and osteoarthritis (OA; n = 12), and in control articular cartilages from patients with femoral neck fracture (n = 8). The distribution of stained chondrocytes was evaluated semiquantitatively in relation to the degree of cartilage destruction. ISNEL-positive chondrocytes with apoptotic morphological features were identified in a relatively early phase of cartilage destruction, and correlated positively and significantly in a number with the degree of cartilage degeneration. Comparison of RA and OA revealed a significantly greater number of ISNEL-positive chondrocytes in RA cartilage. In contrast, the specimens of normal subjects contained few cells with apoptotic changes. Similarly to the distribution of ISNEL staining, the expression of p53 and c-myc proteins was observed in chondrocytes within the degraded lesions, and showed a positive correlation with the number of ISNEL-stained cells. These results suggest that the degree of chondrocyte apoptosis is closely related to cartilage destruction and that chondrocytes in RA more readily undergo apoptosis than those in OA. The expression of p53 and c-myc proteins in ISNEL-positive areas may reflect the involvement of these proteins in the apoptotic process in articular chondrocytes in inflammatory arthritis.

Adult↗