Physical activity and Mediterranean diet based on olive tree phenolic compounds from two different geographical areas have protective effects on early osteoarthritis, muscle atrophy and hepatic steatosis.

PURPOSE: Osteoarthitis (OA) leads to progressive loss of articular cartilage, pain and joint disability. An acute injury constitutes an important risk factor for early OA, determining an inflammatory process responsible of cartilage degeneration and muscle atrophy, due to the joint pain and immobility. The study aims to assess the effects of conjugation of physical activity and diet enriched by olive tree compounds [extra virgin olive oil (EVOO) and olive leaf extract (OLE)], on the musculoskeletal system in OA rat model. METHODS: OA was induced by anterior cruciate ligament transection and confirmed by Mankin and OARSI scores. Rats were subjected to physical activity on treadmill 5 days a week for 10 min daily and fed with experimental diets (standard diet enriched with Sicilian EVOO, Tunisian EVOO and Tunisian EVOO-OLE) for 12 weeks. Immunohistochemistry was used to evaluate IL-6 and lubricin expression in cartilage tissue and ELISA was used to quantify these proteins in serum at different time points. Histology and histomorphometry analysis were done to valuate liver steatosis, muscle atrophy and cartilage pathological changes. RESULTS: Compared to the OA group, the experimental groups showed general increased lubricin and decreased IL-6 expression, significant muscle hypertrophy and no signs of liver steatosis, suggesting the beneficial effects of physical activity coupled with EVOO-enriched diets on rat articular cartilage. Interestingly, the best result was shown for Sicilian EVOO-enriched diet. CONCLUSION: In conclusion, the conjugation of physical activity and EVOO-enriched diet determines a significant articular cartilage recovery process in early OA.

Outcomes of non-invasive ventilation in 'very old' patients with acute respiratory failure: a retrospective study.

BACKGROUND: Non-invasive ventilation (NIV) is increasingly used to support very old (aged ≥85 years) patients with acute respiratory failure (ARF). This retrospective observational study evaluated the impact of NIV on the prognosis of very old patients who have been admitted to the intermediate care unit (IMC) of the Emergency Department of the University Hospital Policlinico-Vittorio Emanuele of Catania for ARF. METHODS: All patients admitted to the IMC between January and December 2015 who received NIV as the treatment for respiratory failure were included in this study. Outcomes of patients aged ≥85 years were compared with lower ages. The expected intrahospital mortality was calculated through the Simplified Acute Physiology Score (SAPS) II and compared with the observed mortality. RESULTS: The mean age was 87.9±2.9 years; the M:F ratio was approximately 1:3. The average SAPS II was 50.1±13.7. The NIV failure rate was 21.7%. The mortality in the very old group was not statistically different from the younger group (20% vs 25.6%; d=5.6%; 95% CI -8% to 19%; p=0.404). The observed mortality was significantly lower than the expected mortality in both the group ≥85 (20.0% vs 43.4%, difference=23.4%; 95% CI 5.6% to 41.1%, p=0.006) and the younger group (25.6% vs 38.5%, difference=12.9%; 95% CI -0.03% to 25.8%, p=0.046). In both age groups, patients treated with NIV for chronic obstructive pulmonary disease had lower mortalities than those treated for other illnesses, although this was statistically significant only in the younger group. CONCLUSION: In very old patients, when used with correct indications, NIV was associated with mortality similar to younger patients. Patients receiving NIV had lower than expected mortality in all age groups.

Nutraceutical Supplements in the Management and Prevention of Osteoarthritis.

Nutraceuticals are dietary compounds which have a role in the balance of anabolic and catabolic signals in joints. Their regulatory function on homeostasis of cartilage metabolism nutraceuticals is increasingly considered for the management and, above all, the prevention of osteoarthritis (OA). OA is a degenerative disease characterized by cartilage and synovium inflammation that can cause joint stiffness, swelling, pain, and loss of mobility. It is a multifactorial disease and, due to the great percentage of people suffering from it and the general increase in life expectancy, OA is considered as one of the most significant causes of disability in the world. OA impairs the structural integrity of articular cartilage that greatly depends on a balance between the anabolic and catabolic processes which occur in chondrocytes and synovial fluid of the joints, therefore the integration with nutraceutical compounds in diet increases the treatment options for patients with established OA beyond traditional rehabilitation, medications, and surgical strategies. In our review, with respect to the current literature, we highlight some of many existing nutraceutical compounds that could be used as integrators in a daily diet thanks to their easy availability, such as in olive oil, fish oil, and botanical extracts used as non-pharmacologic treatment.

Co-Expression and Co-Localization of Cartilage Glycoproteins CHI3L1 and Lubricin in Osteoarthritic Cartilage: Morphological, Immunohistochemical and Gene Expression Profiles.

Osteoarthritis is the most common human arthritis characterized by degeneration of articular cartilage. Several studies reported that levels of human cartilage glycoprotein chitinase 3-like-1 (CHI3L1) are known as a potential marker for the activation of chondrocytes and the progression of Osteoarthritis (OA), whereas lubricin appears to be chondroprotective. The aim of this study was to investigate the co-expression and co-localization of CHI3L1 and lubricin in normal and osteoarthritic rat articular cartilage to correlate their modified expression to a specific grade of OA. Samples of normal and osteoarthritic rat articular cartilage were analyzed by the Kellgren-Lawrence OA severity scores, the Kraus' modified Mankin score and the Histopathology Osteoarthritis Research Society International (OARSI) system for histomorphometric evaluations, and through CHI3L1 and lubricin gene expression, immunohistochemistry and double immuno-staining analysis. The immunoexpression and the mRNA levels of lubricin increased in normal cartilage and decreased in OA cartilage (normal vs. OA, p < 0.01). By contrast, the immunoexpression and the mRNA levels of CHI3L1 increased in OA cartilage and decreased in normal cartilage (normal vs. OA, p < 0.01). Our findings are consistent with reports suggesting that these two glycoproteins are functionally associated with the development of OA and in particular with grade 2/3 of OA, suggesting that in the future they could be helpful to stage the severity and progression of the disease.

Biomarkers of Chondrocyte Apoptosis and Autophagy in Osteoarthritis.

Cell death with morphological and molecular features of apoptosis has been detected in osteoarthritic (OA) cartilage, which suggests a key role for chondrocyte death/survival in the pathogenesis of OA. Identification of biomarkers of chondrocyte apoptosis may facilitate the development of novel therapies that may eliminate the cause or, at least, slow down the degenerative processes in OA. The aim of this review was to explore the molecular markers and signals that induce chondrocyte apoptosis in OA. A literature search was conducted in PubMed, Scopus, Web of Science and Google Scholar using the keywords chondrocyte death, apoptosis, osteoarthritis, autophagy and biomarker. Several molecules considered to be markers of chondrocyte apoptosis will be discussed in this brief review. Molecular markers and signalling pathways associated with chondroycte apoptosis may turn out to be therapeutic targets in OA and approaches aimed at neutralizing apoptosis-inducing molecules may at least delay the progression of cartilage degeneration in OA.

Effects of high-tryptophan diet on pre- and postnatal development in rats: a morphological study.

PURPOSE: Tryptophan is an essential amino acid, precursor of serotonin. Serotonin (5HT) regulates the secretion of pituitary growth hormone (GH), which in turn stimulates the liver to produce insulin-like growth factor-I (IGF-I) that is necessary for development and growth. The aim of our study was to investigate the effects of an excess of tryptophan in the diet of pregnant rats on the differentiation of skeletal muscle tissue. METHODS: We conducted an immunohistochemical study on the IGF-I expression in hepatic and muscle tissues in offspring, and then, we associated this molecular data with morphological effects on the structure of the muscle fibers and hepatic tissue at different postnatal weeks, from birth to sexual maturity. Measurements of 5HT, GH in blood, and of tryptophan hydroxylase (Tph) activity in gastrointestinal tracts tissue were also taken. RESULTS: Hyperserotonemia and higher values of Tph activity were detected in both pregnant rats and pups. Very low levels of GH were detected in experimental pups. Morphological alterations of the muscle fibers and lower IGF-I expression in hepatic and muscle tissue in pups were found. CONCLUSIONS: Our data suggest that an excess of tryptophan in the diet causes hyperserotonemia in fetus. Hyperserotonemia results in an excess of serotonin in the brain where it has an adverse effect on the development of serotonergic neurons. The affected neurons do not regulate optimally the secretion of pituitary GH that consequently decreases. This limits stimulation in the liver to produce IGF-I, crucial for development and growth of pups.

The effects of physical activity on apoptosis and lubricin expression in articular cartilage in rats with glucocorticoid-induced osteoporosis.

Glucocorticoids are considered the most powerful anti-inflammatory and immunomodulating drugs. However, a number of side-effects are well documented in different diseases, including articular cartilage, where increases or decreases in the synthesis of hormone-dependent extracellular matrix components are seen. The objective of this study has been to test the effects of procedures or drugs affecting bone metabolism on articular cartilage in rats with prednisolone-induced osteoporosis and to evaluate the outcomes of physical activity with treadmill and vibration platform training on articular cartilage. The animals were divided into 5 groups, and bone and cartilage evaluations were performed using whole-body scans and histomorphometric analysis. Lubricin and caspase-3 expression were evaluated by immunohistochemistry, Western blot analysis and biochemical analysis. These results confirm the beneficial effect of physical activity on the articular cartilage. The effects of drug therapy with glucocorticoids decrease the expression of lubricin and increase the expression of caspase-3 in the rats, while after physical activity the values return to normal compared to the control group. Our findings suggest that it might be possible that mechanical stimulation in the articular cartilage could induce the expression of lubricin, which is capable of inhibiting caspase-3 activity, preventing chondrocyte death. We can assume that the physiologic balance between lubricin and caspase-3 could maintain the integrity of cartilage. Therefore, in certain diseases such as osteoporosis, mechanical stimulation could be a possible therapeutic treatment. With our results we can propose the hypothesis that physical activity could also be used as a therapeutic treatment for cartilage disease such as osteoarthritis.

Lipids in Liver Failure Syndromes: A Focus on Eicosanoids, Specialized Pro-Resolving Lipid Mediators and Lysophospholipids.

Lipids are organic compounds insoluble in water with a variety of metabolic and non-metabolic functions. They not only represent an efficient energy substrate but can also act as key inflammatory and anti-inflammatory molecules as part of a network of soluble mediators at the interface of metabolism and the immune system. The role of endogenous bioactive lipid mediators has been demonstrated in several inflammatory diseases (rheumatoid arthritis, inflammatory bowel disease, atherosclerosis, cancer). The liver is unique in providing balanced immunotolerance to the exposure of bacterial components from the gut transiting through the portal vein and the lymphatic system. This balance is abruptly deranged in liver failure syndromes such as acute liver failure and acute-on-chronic liver failure. In these syndromes, researchers have recently focused on bioactive lipid mediators by global metabonomic profiling and uncovered the pivotal role of these mediators in the immune dysfunction observed in liver failure syndromes explaining the high occurrence of sepsis and subsequent organ failure. Among endogenous bioactive lipids, the mechanistic actions of three classes (eicosanoids, pro-resolving lipid mediators and lysophospholipids) in the pathophysiological modulation of liver failure syndromes will be the topic of this narrative review. Furthermore, the therapeutic potential of lipid-immune pathways will be described.

Early effects of high-fat diet, extra-virgin olive oil and vitamin D in a sedentary rat model of non-alcoholic fatty liver disease.

BACKGROUND AND AIM: Western high-fat diet is related to metabolic syndrome and non-alcoholic fatty liver disease (NAFLD). Decreased levels of Vitamin D (VitD) and IGF-1 and their mutual relationship were also reported. We aimed to evaluate whether different dietary profiles, containing or not VitD, may exert different effects on liver tissue. METHODS: Twenty-eight male rats were fed for 10 weeks by different dietary regimens: R, regular diet; R-DS and R-DR, regular diet with respectively VitD supplementation (DS) and restriction (DR); HFB-DS and HFB-DR (41% energy from fat), high fat (butter) diet; HFEVO-DS and HFEVO-DR (41% energy from fat), high fat (Extra-virgin olive oil-EVO) diet. Severity of NAFLD was assessed by NAFLD Activity Score. Collagen type I, IL-1beta, VitD-receptor, DKK-1 and IGF1 expressions were evaluated by immunohistochemistry. RESULTS: All samples showed a NAS between 0 and 2 considered not diagnostic of steatohepatitis. Collagen I, although weakly expressed, was statistically greater in HFB-DS and HFB-DR groups. IL-1 was mostly expressed in rats fed with HFBs and HFEVOs and R-DR, and almost absent in R and R-DS diets. IGF-1 and DKK-1 were reduced in HFBs and HFEVOs diets and in particular in DR groups. CONCLUSIONS: A short-term high-fat diet could damage liver tissue in terms of inflammation and collagen I deposition, setting the basis for the subsequent steatohepatitis, still not identifiable anatomopathologically. Vitamin D restriction increases inflammation and reduces the expression of IGF-1 in the liver, worsening the fat-induced changing. EVOO seems be protective against the collagen I production.

Impact of Western and Mediterranean Diets and Vitamin D on Muscle Fibers of Sedentary Rats.

BACKGROUND: The metabolic syndrome is associated with sarcopenia. Decreased serum levels of Vitamin D (VitD) and insulin-like growth factor (IGF)-1 and their mutual relationship were also reported. We aimed to evaluate whether different dietary profiles, containing or not VitD, may exert different effects on muscle molecular morphology. METHODS: Twenty-eight male rats were fed for 10 weeks in order to detect early defects induced by different dietary regimens: regular diet (R); regular diet with vitamin D supplementation (R-DS) and regular diet with vitamin D restriction (R-DR); high-fat butter-based diets (HFB-DS and HFB-DR) with 41% energy from fat; high-fat extra-virgin olive oil-based diets (HFEVO-DS and HFEVO-DR) with 41% energy from fat. IL-1ß, insulin-like growth factor (IGF)1, Dickkopf-1 (DKK-1), and VitD-receptor (VDR) expressions were evaluated by immunohistochemistry. Muscle fiber perimeter was measured by histology and morphometric analysis. RESULTS: The muscle fibers of the HEVO-DS rats were hypertrophic, comparable to those of the R-DS rats. An inverse correlation existed between the dietary fat content and the perimeter of the muscle fibers (p < 0.01). In the HFB-DR rats, the muscle fibers appeared hypotrophic with an increase of IL-1ß and a dramatic decrease of IGF-1 expression. CONCLUSIONS: High-fat western diet could impair muscle metabolism and lay the ground for subsequent muscle damage. VitD associated with a Mediterranean diet showed trophic action on the muscle fibers.

Molecular Links Between Diabetes and Osteoarthritis: The Role of Physical Activity.

BACKGROUND: Diabetes mellitus (DM) and osteoarthritis (OA) are two of the most relevant and common chronic diseases affecting older people. Both DM and OA are considered metabolic diseases due to their high correlation with the capacity of the body to metabolize some nutritive substances such as glucose, fat, vitamins and also the response to oxidative molecules. METHODS: We searched PubMed, Scopus, Google Scholar, and authors' bibliographies in order to extract articles regarding the relationship between DM and OA. OBJECTIVE: The main purpose of this review is to investigate the molecules involved in the onset and progression of both DM and OA and the beneficial role of physical activity. RESULTS: The main focus is on the importance of glucose metabolism and its derivatives in the pathogenesis of OA and DM. Advanced glycation end-product (AGEs), sorbitol and diacylglycerol (DAG) are glucose derivatives which promote the activation of several pathways, most of them involved in the activation of inflammatory processes. The possible link between DM and OA is represented by the inflammatory process deriving from the increased expression of pro-inflammatory cytokines. Moreover, we investigated the biological mechanisms and the clinical findings that confirm a beneficial effect of physical activity in both DM and OA. CONCLUSION: Thus a tailored and adapted physical activity can be used in the treatment of both diseases as a part of a correct and healthy lifestyle. For this reason we strongly suggest the scientific community to introduce mild physical activity as part of our lifestyle to prevent metabolism diseases and osteoarthritis.

The role of ultrasound-guided fine needle aspiration biopsy in musculoskeletal diseases.

Ultrasonography (US) is a readily available non-invasive tool useful for the detection of musculoskeletal and soft tissue masses. Although X-Ray is often the first imaging study for evaluating both bone and soft tissue lesions, and magnetic resonance imaging and computed tomography are mandatory in lesions staging, US is increasingly used for the early assessment of musculoskeletal and soft-tissue masses and for guiding procedures and biopsies. Surgical biopsy or fine needle aspiration biopsy (FNAB) is needed to ascertain the nature of any lesion. FNAB is a low cost technique, safer and less traumatic than an open surgical biopsy. Significant complications are rare, mostly related to the site of biopsy. Knowledge of indications, limitations, anatomical and pathological access, adequate technical expertise in US imaging and in intervention skills are the critical factors of the appropriate and safe use of FNAB. By now, the role of FNAB in musculoskeletal diseases is controversial and there is still a heated debate in the scientific community.

The importance of physical activity in osteoporosis. From the molecular pathways to the clinical evidence.

Osteoporosis is a very common bone disorder characterized by low bone mass and signs of deterioration, responsible for bone fragility typical in this pathology. The risk factors for the onset of osteoporosis are many and different from each other. Some of them cannot be modified, such as age, hereditary diseases and endocrine diseases. Others are modifiable, so that prevention is an advisable tool to reduce the incidence of osteoporosis. Among preventive tools, physical activity is certainly a valid instrument of prevention, in fact physical activity contributes to a healthy energy balance and increases muscle mass and bone mass. In the present narrative review, we wanted to pay attention to the possible influence of physical activity on the pathophysiological molecular pathways of osteoporosis and to the use of different exercise training in treatment of osteoporosis. From the literature analyzed, in relation to the effects of physical activity on bone metabolism, it is shown that exercise acts on molecular pathways of bone remodeling involving all cellular types of bone tissue. In relation to clinical trials adopted in patients with osteoporosis, it is evident that a multi-component training, including aerobic activity and other types of training (resistance and/or strength exercises), is the best kind of exercise in improving bone mass and bone metabolism in older adults and especially osteopoenic and osteoporotic women. With regard to whole-body-vibration training, it seems to be a valid alternative to current methods due to its greater adaptability to patients. In conclusion, physical activity, whatever the adopted training, always has beneficial effects on patients suffering from osteoporosis, and not only on bone homeostasis but on the whole skeletal muscle system.

Importance of serotonin (5-HT) and its precursor l-tryptophan for homeostasis and function of skeletal muscle in rats. A morphological and endocrinological study.

Serotonin (5-HT) is a neurotransmitter, synthesized in serotonergic neurons of the central nervous system and in enterochromaffin cells of the gastrointestinal tract, which is involved in the regulation of several body functions, including muscle tissue development and growth and its contractile response. l-Tryptophan (l-Trp) is an essential amino acid and precursor of 5-HT. The aim of the present study was to better understand the mechanisms that govern neuroendocrine homeostasis of muscle tissue and emphasize the importance of a diet, complete in all its elements, referring specifically to the essential amino acids such as l-Trp, crucial in several neuroendocrine functions.We analyzed the possible consequences of l-Trp-free diet on 5-HT production and on skeletal muscle morphology and function in young female rats. We also evaluated the eventual alterations of hormone production such as growth hormone (GH), thyroid stimulating hormone (TSH) and thyroid hormones (T3 and T4) that control and regulate growth, metabolism and efficiency of the skeletal muscle. Our results showed a strong decrease of 5-HT, GH, TSH, T3 and T4 levels associated to a clear difference in body weight between experimental and control rats. Moreover, the muscle samples of experimental rats showed histological and ultrastructural alterations. These findings thus supported a strong link between l-Trp, serotonergic system, hormone secretion and morphology of skeletal muscle tissue and thus, the importance of a balanced daily diet.

4Ps medicine of the fatty liver: the research model of predictive, preventive, personalized and participatory medicine-recommendations for facing obesity, fatty liver and fibrosis epidemics.

Relationship between adipose tissue and fatty liver, and its possible evolution in fibrosis, is supported by clinical and research experience. Given the multifactorial pathogenesis of non-alcoholic fatty liver disease (NAFLD), treatments for various contributory risk factors have been proposed; however, there is no single validated therapy or drug association recommended for all cases which can stand alone. Mechanisms, diagnostics, prevention and treatment of obesity, fatty liver and insulin resistance are displayed along with recommendations and position points. Evidences and practice can get sustainable and cost-benefit valuable outcomes by participatory interventions. These recommendations can be enhanced by comprehensive research projects, addressed to societal issues and innovation, market appeal and industry development, cultural acceptance and sustainability. The basis of participatory medicine is a greater widespread awareness of a condition which is both a disease and an easy documented and inclusive clue for associated diseases and unhealthy lifestyle. This model is suitable for addressing prevention and useful for monitoring improvement, worsening and adherence with non-invasive imaging tools which allow targeted approaches. The latter include health psychology and nutritional and physical exercise prescription expertise disseminated by continuous medical education but, more important, by concrete curricula for training undergraduate and postgraduate students. It is possible and recommended to do it by early formal teaching of ultrasound imaging procedures and of practical lifestyle intervention strategies, including approaches aimed to healthier fashion suggestions. Guidelines and requirements of research project funding calls should be addressed also to NAFLD and allied conditions and should encompass the goal of training by research and the inclusion of participatory medicine topics. A deeper awareness of ethics of competences in health professionals and the articulation of knowledge, expertise and skills of medical doctors, dieticians, health psychologists and sport and physical exercise graduates are the necessary strategy for detectin a suboptimal health status and achieving realistically beneficial lifestyle changes. "The devil has put a penalty on all things we enjoy in life. Either we suffer in health or we suffer in soul or we get fat" (Albert Einstein); the task of medical research and intervention is to make possible to enjoy life also without things that make sufferance in health and souls and which excessively increase body fat.

Serotonin (5HT) expression in rat pups treated with high-tryptophan diet during fetal and early postnatal development.

Serotonin (5HT) is a neurotransmitter synthesized in serotonergic neurons of the central nervous system and in the enterochromaffin cells of the gastrointestinal tract. 5HT regulates growth and maturation of some cerebral regions in the developing brain as well as the secretion of pituitary growth hormone. This hormone is necessary for development and growth through the stimulation of insulin-like growth factor synthesis. The precursor of 5HT, tryptophan (Trp), is an essential amino acid, since the human organism is unable to synthesize it and it is assumed only through diet. The aim of our study was to analyze how a high-tryptophan diet in pregnant rats affects growth and survival of pups until weaning. We monitored the number and weight of pups until weaning. Then, we detected serotonin and growth hormone levels in whole blood by ELISA of surviving pups at the end of the lactation period. We also analyzed by means of immunohistochemistry and Western blot the expression of serotonin in rat gastric tissue and the morphological structure of skeletal muscle tissue of both control and experimental pups. Hyperserotonemia and very low levels of growth hormone were detected in experimental pups compared to controls. Immunohistochemistry demonstrated a strong serotonin expression in stomach samples confirming that a high intake of tryptophan increases the production of serotonin in enterochromaffin cells, thereby resulting in hyperserotonemia in pups. These data were also strengthened by Western blot analysis. Histological alterations of skeletal muscle fibers in experimental pups were found and showed that in experimental samples the muscle tissue demonstrated deleterious alterations, being less developed and defined. Our data suggest that a high-tryptophan diet in pregnant rats induces hyperserotonemia in the fetus. Hyperserotonemia results in an excess of serotonin in the brain where it has a negative influence on development of serotonergic neurons and consequently on growth hormone production.

Post-operative rehabilitation and nutrition in osteoarthritis.

Osteoarthritis (OA) is a degenerative process involving the progressive loss of articular cartilage, synovial inflammation and structural changes to the subchondral bone that lead to loss of synovial joint structural features and impaired functionality of the articular cartilage. OA represents one of the most common causes of physical disability in the world. Different OA treatments are usually considered in relation to the stage of the disease. However, in the earlier stages of the disease, it is possible to recommend physical activity programs that can maintain joint health and keep the patient mobile, as recommended by the Osteoarthritis Research Society International (OARSI) and the European League Against Rheumatism (EULAR). In the most severe and advanced cases of OA, surgical intervention is necessary. In early post-operative stages, it is essential to include rehabilitation exercise program therapies in order to restore the full function of the involved joint. Physical therapy is crucial for the success of any surgical procedure and can promote recovery of muscle strength, range of motion, coordinated walking, proprioception and mitigate joint pain. After discharge from the hospital, patients should continue the rehabilitation exercise program at home. In this review, we analyze articles from the most recent literature and provide a balanced and comprehensive overview of the latest discoveries in relation to the effects of physical exercise on post-operative rehabilitation in OA. The literature search was conducted in April 2014 using PubMed, Scopus and Google Scholar using the keywords 'osteoarthritis', 'rehabilitation' and 'exercise', in a range of period 2002/2014 and out of 100 papers we have chosen 48 that we considered more appropriate. The available data suggests that physical exercise is effective, economical and accessible to everyone, and is one of the most important components of post-operative rehabilitation for OA.

Lubricin expression in human osteoarthritic knee meniscus and synovial fluid: a morphological, immunohistochemical and biochemical study.

The purpose of this study was to investigate the expression of lubricin, the product of the human PRG4 (proteoglycan 4) gene, in menisci and synovial fluid from normal donors and patients with osteoarthritis (OA), using a combination of histology, immunohistochemistry, ELISA and Western blotting analysis, to provide further insight on the role of this protein in the progression of OA and pathological processes in the meniscus. Lubricin expression was studied in samples from 40 patients and in 9 normal donors after arthroscopic partial meniscectomy. Histological analysis confirmed normal microanatomy and the absence of structural changes in control samples. Menisci derived from OA patients showed evidence of structural alterations, fibrillations and clefts. Immunohistochemical analysis revealed very strong lubricin immunostaining in normal menisci in contrast to weak/moderate staining seen in osteoarthritic menisci. Quantitative ELISA and Western blot analysis confirmed the above results. The findings of this study support the notion that changes in lubricin expression and boundary-lubricating ability of cartilage is followed by the development of OA. This study could provide the biological foundation for the development of novel therapeutic treatments, to be applied before the surgery, for the prevention of post-traumatic cartilage damage.