Diabetes-accelerated experimental osteoarthritis is prevented by autophagy activation.

OBJECTIVE: Type 2 Diabetes (T2D) is a risk factor for osteoarthritis (OA). Autophagy, an essential homeostasis mechanism in articular cartilage, is defective in T2D and OA. However, how T2D may influence OA progression is still unknown. We aimed to determine how diabetes affects cartilage integrity and whether pharmacological activation of autophagy has efficacy in diabetic mice (db/db mice) with OA. DESIGN: Experimental OA was performed in the right knee of 9 weeks-old C57Bl/6J male mice (Lean group, N = 8) and of 9 weeks-old B6.BKS (D)-Leprdb male mice (db/db group, N = 16) by transection of medial meniscotibial and medial collateral ligaments. Left knee was employed as control knee. Rapamycin (2 mg/kg weight/day) or Vehicle (dimethyl sulfoxide) were administered intraperitoneally three times a week for 10 weeks. Histopathology of articular cartilage and synovium was evaluated by using semiquantitative scoring and synovitis grading systems, respectively. Immunohistochemistry was employed to evaluate the effect of diabetes and Rapamycin on cartilage integrity and OA biomarkers. RESULTS: Cartilage damage was increased in db/db mice compared to Lean mice after experimental OA, while no differences are observed in the control knee. Cartilage damage and synovium inflammation were reduced by Rapamycin treatment of OA-db/db mice. This protection was accompanied with a decrease in MMP-13 expression and decreased interleukin 12 (IL-12) levels. Furthermore, autophagy was increased and cartilage cellularity was maintained, suggesting that mammalian target of rapamycin (mTOR) targeting prevents joint physical harm. CONCLUSION: Our findings indicate that diabetic mice exhibit increased joint damage after experimental OA, and that autophagy activation might be an effective therapy for diabetes-accelerated OA.

Insulin decreases autophagy and leads to cartilage degradation.

OBJECTIVE: Autophagy, a key homeostasis mechanism, is defective in Osteoarthritis (OA) and Type 2 Diabetes (T2D). T2D has been proposed as a risk factor for OA. We hypothesized that diabetes impairs articular cartilage integrity by decreasing autophagy. Our objective was to investigate the effects of high glucose and insulin, characteristics of T2D, on cartilage homeostasis. METHODS: Immortalized human chondrocytes (TC28a2) and primary human chondrocytes (HC) were cultured in 25 mM or 0 mM glucose and treated with insulin (10, 100, 500 nM) for 2, 6 or 24 h. Activity of LC3-II, Akt and rpS6 was evaluated by Western blotting (WB). Human cartilage explants were cultivated with 25 mM glucose and insulin (100,1000 nM) for 24 h to evaluate histopathology. MMP-13 and IL-1ß expression was determined by immunohistochemistry and WB. Effects of Rapamycin (10 µM) were analyzed by WB. LC3 and rpS6 expression was determined by WB in chondrocytes from Healthy, Non Diabetic-OA and Diabetic-OA patients. RESULTS: Insulin downregulates autophagy by reducing LC3 II expression and increasing Akt and rpS6 phosphorylation. Loss of proteoglycans and increased MMP-13 and IL-1ß expression was observed after insulin treatment. Autophagy activation by rapamycin reversed insulin effects. Importantly, chondrocytes from diabetic-OA patients showed decreased LC3 and increased p-rpS6 expression compared to Healthy and Non-Diabetic OA patients. CONCLUSIONS: These results suggest that decreased autophagy might be a mechanism by which diabetes influences cartilage degradation. Pharmacological activation of autophagy may be an effective therapeutic approach to prevent T2D-induced cartilage damage.

Cortical strut allografting in reconstructive orthopaedic surgery.

Many approaches are used in the repair of skeletal defects in reconstructive orthopaedic surgery, and bone grafting is involved in virtually every procedure. Autografting remains the gold standard for replacing bone loss. However, the limited amount of bone that can be harvested and the morbidity associated with that procedure are major constraints to the clinical use of autografts. In contrast, bone allografts can be used in any kind of surgery, whether involving minor defects or major bone loss. Cortical strut allografts unite to host bone through callus formation, restoring bone stock and can be used as an onlay biological plate. These struts can be made from hemicylinders of tibia being fixed to host bone by circumferential metallic cables or by screws. The purpose of this study was to analyze the radiographic outcomes of twelve cryopreserved cortical onlay strut allografts, used in a group of nine patients, for revision hip arthroplasty of the femoral side, to stabilize femoral periprosthetic fractures, to reinforce poor cortical bone and to treat one atrophic femoral nonunion. The average follow-up period was 4.3 years (range, 1.6 to 9 years). No fractures, nonunions or progressive resorption of the bone allografts were observed. All struts were incorporated to the native femur with minimal resorption, within the first year after surgery. There was no failure of any of the allograft reconstructions.The results obtained show that cortical onlay strut allografts, either alone or in conjunction with metallic plate or cancellous bone allografts, are a valuable adjunct for reconstructive surgery of the hip and to treat atrophic femoral nonunion.

Expression and function of the insulin receptor in normal and osteoarthritic human chondrocytes: modulation of anabolic gene expression, glucose transport and GLUT-1 content by insulin.

OBJECTIVE: Chondrocytes respond to insulin, but the presence and role of the specific high affinity insulin receptor (InsR) has never been demonstrated. This study determined whether human chondrocytes express the InsR and compared its abundance and function in normal and osteoarthritis (OA) human chondrocytes. DESIGN: Cartilage sections were immunostained for detection of the InsR. Non-proliferating chondrocyte cultures from normal and OA human cartilage were treated with 1nM or 10nM insulin for various periods. InsR, insulin-like growth factor receptor (IGFR), aggrecan and collagen II mRNA levels were assessed by real time RT-PCR. InsR, glucose transporter (GLUT)-1, phospho-InsRbeta and phospho-Akt were evaluated by western blot and immunofluorescence. Glucose transport was measured as the uptake of [3H]-2-Deoxy-d-Glucose (2-DG). RESULTS: Chondrocytes staining positively for the InsR were scattered throughout the articular cartilage. The mRNA and protein levels of the InsR in OA chondrocytes were approximately 33% and 45%, respectively, of those found in normal chondrocytes. Insulin induced the phosphorylation of the InsRbeta subunit. Akt phosphorylation and 2-DG uptake increased more intensely in normal than OA chondrocytes. Collagen II mRNA expression increased similarly in normal and OA chondrocytes while aggrecan expression remained unchanged. The Phosphoinositol-3 Kinase (PI3K)/Akt pathway was required for both basal and insulin-induced collagen II expression. CONCLUSIONS: Human chondrocytes express functional InsR that respond to physiologic insulin concentrations. The InsR seems to be more abundant in normal than in OA chondrocytes, but these still respond to physiologic insulin concentrations, although some responses are impaired while others appear fully activated. Understanding the mechanisms that regulate the expression and function of the InsR in normal and OA chondrocytes can disclose new targets for the development of innovative therapies for OA.

Experiencing genetic counselling for hereditary cancers: the client's perspective.

As genetic health care expands and genetic testing becomes more widely available, it becomes relevant to understand how individuals involved in genetic counselling are integrating this new information in health management and into their lives. This article examines the client's experiences of genetic counselling for hereditary cancers, which definitely play a major role in the assessment of their needs and also lead to improvement of the psychosocial focus in genetic counselling protocols. Methods include a semi-structured interview, administered in two focus groups, comprising 10 (5 + 5) participants after attending genetic counselling for hereditary cancers at a Portuguese public hospital. Findings suggest an experience embedded in two dimensions: (1) instrumental (goals, needs and decision making); and (2) emotional (uncertainty regarding genetic risk screening and an emotional complex). Ambiguity plays a crucial role, especially in two moments: (1) the hiatus between genetic testing and the screening results; and (2) after being confirmed as carrying a cancer susceptibility gene mutation. The spectrum of genetic illness comprises an intensely complex emotional experience that challenges individuals and their families in terms of health management, and personal and family planning. Recommendations are included in order to enhance the services available by expanding psychosocial support.

Assessment of strategies to increase chondrocyte viability in cryopreserved human osteochondral allografts: evaluation of the glycosylated hydroquinone, arbutin.

OBJECTIVE: Allogeneic cartilage is used to repair damaged areas of articular cartilage, requiring the presence of living chondrocytes. So far, no preservation method can effectively meet that purpose. Identification of more effective cryoprotective agents (CPAs) can contribute to this goal. The aim of this study was to determine whether the glycosylated hydroquinone, arbutin, alone or in combination with low concentrations of other CPAs, has cryoprotective properties towards human articular cartilage. MATERIAL AND METHODS: Human tibial plateaus were procured from multi-organ donors, with the approval of the Ethics Committee of the University Hospital of Coimbra. The tibial plateaus were treated with or without arbutin (50 or 100mM), alone or in combination with various concentrations of dimethyl sulfoxide (DMSO) and glycerol, for 0.5-1.5h/37 degrees C, then frozen at -20 degrees C and 24h later transferred to a biofreezer at -80 degrees C. Two to 3 months later, thawing was achieved by immersion in cell culture medium at 37 degrees C/1h. Chondrocyte viability was assessed before and after freeze-thawing using a colorimetric assay based on the cell's metabolic activity and fluorescent dyes to evaluate cell membrane integrity. RESULTS: Before freezing, chondrocyte metabolic activity was identical in all the conditions tested. After freeze-thawing, the highest activity, corresponding to 34.2+/-2.1% of that in the Fresh Control, was achieved in tibial plateaus incubated in 50mM arbutin for 1h whereas in those left untreated it was 11.1+/-4.7. Addition of DMSO and glycerol to arbutin did not increase chondrocyte viability any further. Fluorescence microscopy confirmed these results and showed that living chondrocytes were mainly restricted to the superficial cartilage layers. CONCLUSION: Arbutin seems to be an effective cryoprotective agent for osteochondral allografts with potential benefits over DMSO and glycerol.

Nitric oxide synthase isoforms and NF-kappaB activity in normal and osteoarthritic human chondrocytes: regulation by inducible nitric oxide.

To elucidate the role of endogenous inducible nitric oxide (NO) on the regulation of NF-kappaB activity in human chondrocytes, we evaluated (i) the pattern of expression of the neuronal (nNOS) and inducible (iNOS) NO synthase isoforms and the basal NF-kappaB activity in normal and osteoarthritic (OA) human chondrocytes, (ii) the role of cytokines and growth factors in modulating the protein levels of the two NOS isoforms, and (iii) the effect of inhibiting endogenous inducible NO production on the ability of interleukin-1beta (IL-1) to induce NF-kappaB activation. nNOS was more frequently expressed in normal than in OA chondrocytes, whereas the opposite was found for iNOS. IL-1 induced the degradation of both enzymes, but iNOS disappeared more rapidly. Although IkappaB-alpha was present in all the normal samples and in the majority of the OA samples, NF-kappaB-DNA binding activity in OA chondrocytes was increased approximately twofold relatively to normal cells. Addition of a NOS inhibitor, after induction of iNOS expression, induced IkappaB-alpha degradation and potenciated the effect of IL-1, indicating that endogenous inducible NO inhibits NF-kappaB activation. Taken together, these findings favor an inhibitory role of high NO levels on the regulation of NF-kappaB activation in chondrocytes, indicating that NF-kappaB activity is regulated, at least in part, by the balanced production of NO resulting from a dynamic process that, at any given moment, determines the availability of the constitutive and inducible NOS isoforms. Moreover, the down-regulatory role of NO on NF-kappaB activation warrants caution as to the possible utilization of NO inhibitors in the therapy of OA.

Dexamethasone-induced and estradiol-induced CREB activation and annexin 1 expression in CCRF-CEM lymphoblastic cells: evidence for the involvement of cAMP and p38 MAPK.

AIMS: Annexin 1 (ANXA1), a member of the annexin family of calcium-binding and phospholipid-binding proteins, is a key mediator of the anti-inflammatory actions of steroid hormones. We have previously demonstrated that, in the human lymphoblastic CCRF-CEM cell line, both the synthetic glucocorticoid hormone, dexamethasone (Dex), and the estrogen hormone, 17beta-estradiol (E2beta), induce the synthesis of ANXA1, by a mechanism independent of the activation of their nuclear receptors. Recently, it was reported that the gene coding for ANXA1 contains acAMP-responsive element (CRE). In this work, we investigated whether Dex and E2beta were able to induce the activation of CRE binding proteins (CREB) in the CCRF-CEM cells. Moreover, we studied the intracellular signalling pathways involved in CREB activation and ANXA1 synthesis in response to Dex and E2beta; namely, the role of cAMP and the p38 mitogen activated protein kinase (MAPK). RESULTS: The results show that Dex and E2beta were as effective as the cAMP analogue, dBcAMP, in inducing CREB activation. On the contrary, dBcAMP induced ANXA1 synthesis as effectively as these steroid hormones. Furthermore, the cAMP antagonist, Rp-8-Br-cAMPS, and the specific p38 MAPK inhibitor,SB203580, effectively prevented both Dex-induced, E2beta-induced and dBcAMP-induced CREB activation and ANXA1 synthesis. CONCLUSIONS: Taken together, our results suggest that,in CCRF-CEM cells, Dex-induced and E2beta-inducedANXA1 expression requires the activation of the transcription factor CREB, which in turn seems to be mediated by cAMP and the p38 MAPK. These findings also suggest that, besides the nuclear steroid hormone receptors, other transcription factors, namely CREB, may play important roles in mediating the anti-inflammatory actions of glucocorticoids and oestrogen hormones.

Dexamethasone prevents interleukin-1beta-induced nuclear factor-kappaB activation by upregulating IkappaB-alpha synthesis, in lymphoblastic cells.

AIMS: Glucocorticoids (GCs) exert some of their anti-inflammatory actions by preventing the activation of the transcription factor nuclear factor (NF)-kappaB. The GC-dependent inhibition of NF-kappaB may occur at different levels, but the mechanisms involved are still incompletely understood. In this work, we investigated whether the synthetic GC, dexamethasone (Dex), modulates the activity of NF-kappaB in the lymphoblastic CCRF-CEM cell line. We also evaluated the ability of Dex to prevent the activation of NF-kappaB in response to the potent proinflammatory cytokine, interleukin (IL)-1beta. RESULTS: Exposure of the cells to Dex (1 microM) induced the rapid degradation of IkappaB-alpha, leading to the transient translocation of the NF-kappaB family members p65 and p50 from the cytoplasm to the nucleus, as evaluated by western blot. Electrophoretic mobility shift assays revealed that, in the nucleus, these NF-kappaB proteins formed protein-DNA complexes, indicating a transient activation of NF-kappaB. Additionally, Dex also induced de novo synthesis of IkappaB-alpha, following its degradation. Finally, when the cells were exposed to Dex (1 microM) prior to stimulation with IL-1beta (20 ng/ml), Dex was efficient in preventing IL-1beta-induced NF-kappaB activation. The GC antagonist, RU 486 (10 microM), did not prevent any of the effects of Dex reported here. CONCLUSION: Our results indicate that, in CCRF-CEM cells, Dex prevents NF-kappaB activation, induced by IL-1beta, by a mechanism that involves the upregulation of IkappaB-alpha synthesis, and that depends on the early and transient activation of NF-kappaB.

Role of nitric oxide in the activation of NF-kappaB, AP-1 and NOS II expression in articular chondrocytes.

OBJECTIVE AND DESIGN: Determine the sources of nitric oxide (NO) and evaluate its role in the activation of nuclear Factor-kappaB (NF-kappaB) and activator protein-1 (AP-1) and in the expression of NO synthase II (NOS II), induced by interleukin-1beta (IL-1). MATERIAL OR SUBJECTS: Primary cultures of bovine articular chondrocytes. TREATMENT: The cells were treated with IL-1, 5 ng/ml with or without the NO donor S-nitroso-N-acetylpenicillamine (SNAP), in concentrations ranging from 10 to 300 microM. METHODS: NF-kappaB and AP-1 activation were evaluated by electrophoretic mobility shift assay. Northern blot was used to detect NOS II mRNA levels and western blot to evaluate IkappaB-alpha, NOS I and NOS II protein levels. RESULTS: Under basal conditions, chondrocytes expressed NOS I, which was lost upon IL-I treatment. SNAP inhibited IL-I-induced NF-kappaB activation and NOS II expression. When added alone, SNAP induced AP-1 activation to approximately the same extent as IL-I. CONCLUSIONS: These results suggest that, in chondrocytes, NO is a key regulator of the signaling pathways leading from IL-I to NF-kappaB and AP-1 activation and to the expression of genes that are involved in the pathophysiology of arthritic diseases.

Diphenyleneiodonium inhibits NF-kappaB activation and iNOS expression induced by IL-1beta: involvement of reactive oxygen species.

AIMS: In this work, we studied the mechanisms by which diphenyleneiodonium chloride (DPI) inhibits nitric oxide (NO) synthesis induced by the proinflammatory cytokine interleukin-1beta (IL-1) in bovine articular chondrocytes. To achieve this, we evaluated the ability of DPI to inhibit the expression and activity of the inducible isoform of the NO synthase (iNOS) induced by IL-1. We also studied the ability of DPI to prevent IL-1-induced NF-kappaB activation and reactive oxygen species (ROS) production. RESULTS: Northern and Western blot analysis, respectively, showed that DPI dose-dependently inhibited IL-1-induced iNOS mRNA and protein synthesis in primary cultures of bovine articular chondrocytes. DPI effectively inhibited NO production (IC50=0.03+/-0.004 microM), as evaluated by the method of Griess. Nuclear factor-kappa B (NF-kappaB) activation, as evaluated by electrophoretic mobility shift assay, was inhibited by DPI (1-10 microM) in a dose-dependent manner. IL-1-induced ROS production, as evaluated by measurement of dichlorofluorescein fluorescence, was inhibited by DPI at concentrations that also prevented NF-kappaB activation and iNOS expression. CONCLUSIONS: DPI inhibits IL-1-induced NO production in chondrocytes by two distinct mechanisms: (i) by inhibiting NOS activity, and (ii) by preventing iNOS expression through the blockade of NF-kappaB activation. These results also support the involvement of reactive oxygen species in IL-1-induced NF-kappaB activation and expression of NF-kappaB-dependent genes, such as iNOS.

Head and neck squamous cell carcinoma in childhood.

BACKGROUND: Squamous cell carcinoma (SCC) of the head and neck region is rare in young patients and even less frequent in children 15 years or younger children. The patients reported in the literature are isolated cases and their management is always difficult because there is no large experience or a convincing theory to support treatment decisions for every child. PROCEDURES AND RESULTS: Four patients aged 15 years or younger were treated for SCC of head and neck between 1977 and 1995 at the Head and Neck Service of Heliópolis Hospital, São Paulo, Brazil, and with this paper we are reporting our experience with their treatment, including a genetic investigation in two cases (immunohistochemical analysis using monoclonal antibodies against p53 and c-erbB-2 oncogenes). These patients had no history of tobacco or ethanol abuse and no history of cancer in their families. Many authors attribute an unusual aggressiveness to SCC in childhood, with propensity to locoregional recurrence and high death rates and therefore, propose aggressive multidisciplinary therapy. Our cases, with the exception of one, had an early diagnosis and were treated using the same method we use for adults; the results were very good. CONCLUSIONS: We recommend for these cases the same protocol as for older patients. In these cases, however, the primary lesion is resected with a safety margin which is usually 2 to 3 mm larger than usual safety margins and selective neck dissection is routinely indicated. This management is adopted in an attempt to avoid postoperative irradiation which may prove to be dangerous in the future for young patients. On the other hand, we recognize that due to a small number de patients, definitive treatment recommendations cannot be made at this time.

Changes in the subcellular distribution of the rat uterus oestrogen receptor as induced by oestradiol, tamoxifen and ZD 182,780.

The aim of this work was to compare the subcellular distribution of the oestrogen receptor from the uteri of rats treated with vehicle alone (control group), oestradiol or one of the anti-oestrogenic drugs tamoxifen and ZD 182,780. The nuclear, microsomal and cytosolic oestrogen receptor contents were evaluated by an immunoenzymatic method ("ER-EIA" kit from Abbott Laboratories) and the results in each fraction were expressed as a percentage of the total number of receptors. Parallel studies were performed to assess the uterotrophic effect of these drugs and to assess that they had reached the uterus. In the control group, we found that the oestrogen receptor was distributed mainly between the microsomal (29.1 +/- 1.3%) and cytosolic (68.1 +/- 0.9%) fractions, with only a small amount located in the nucleus (2.8 +/- 0.5%). When oestradiol was administered, the oestrogen receptor distribution was: nuclear 11.7 +/- 2.0, microsomal 15.5 +/- 1.3 and cytosolic 72.8 +/- 3.3% and, in the tamoxifen group, the results were: nuclear 18.5 +/- 1.5, microsomal 26.0 +/- 3.1 and cytosolic 55.5 +/- 3.4%, which shows a relative shift both to the control and the oestradiol-treated groups. In the uteri of rats treated with ZD 182,780 the results were very similar to those obtained in the control group. Our results indicate that the subcellular distribution of the oestrogen receptor varies according to the drug administered and that this receptor may not be located in a single subcellular compartment. Moreover, the nuclear uptake of the ZD 182,780-oestrogen receptor complex seems to be blocked, possibly due to impaired receptor dimerization. In the case of tamoxifen, the intracellular transport of the receptor also seems to be blocked, probably due to the nuclear retention of the receptor, thus suggesting that tamoxifen must impair the oestrogen receptor function on a step subsequent to the receptor dimerization.