p38ß (MAPK11) mediates gemcitabine-associated radiosensitivity in sarcoma experimental models.

BACKGROUND AND PURPOSE: Gemcitabine is an antitumour agent currently used in the treatment of several types of cancer with known properties as a radiosensitizer. p38MAPK signalling pathway has been shown to be a major determinant in the cellular response to gemcitabine in different experimental models. However, the molecular mechanism implicated in gemcitabine-associated radiosensitivity remains unknown. MATERIALS AND METHODS: The human sarcoma cell lines A673 and HT1080, and a mouse cell line derived from a 3-methylcholanthrene induced sarcoma were used as experimental models. Modulation of p38MAPKs was performed by pharmacological approaches (SB203580) and genetic interference using lentiviral vectors coding for specific shRNAs. Viability was assessed by MTT. Gene expression was evaluated by western blot and RT-qPCR. Induction of apoptosis was monitored by caspase 3/7 activity. Response to ionizing radiation was evaluated by clonogenic assays. RESULTS: Our data demonstrate that chemical inhibition of p38MAPK signalling pathway blocks gemcitabine radiosensitizing potential. Genetic interference of MAPK14 (p38α), the most abundantly expressed and best characterized p38MAPK, despite promoting resistance to gemcitabine, it does not affect its radiosensitizing potential. Interestingly, specific knockdown of MAPK11 (p38ß) induces a total loss of the radiosensitivity associated to gemcitabine, as well as a marked increase in the resistance to the drug. CONCLUSION: The present work identifies p38ß as a major determinant of the radiosensitizing potential of gemcitabine without implication of p38α, suggesting that p38ß status should be analysed in those cases in which gemcitabine is combined with ionizing radiation.

P53 pathway is a major determinant in the radiosensitizing effect of Palbociclib: Implication in cancer therapy.

Targeting cell cycle has become one of the major challenges in cancer therapy, being Palbociclib, a CDK4/6 inhibitor, an excellent example. Recently, it has been reported that Palbociclib could be a novel radiosensitizer agent. In an attempt to clarify the molecular basis of this effect we have used cell lines from colorectal (HT29, HCT116) lung (A549, H1299) and breast cancer (MCF-7). Our results indicate that the presence of a p53 wild type is strictly required for Palbociclib to exert its radiosensitizing effect, independently of the inhibitory effect exerted on CDK4/6. In fact, abrogation of p53 in cells with functional p53 blocks the radiosensitizing effect of Palbociclib. Moreover, no radiosensitizing effect is observed in cells with non-functional p53, but restoration of p53 function promotes radiosensitivity associated to Palbociclib. Furthermore, the presence of Palbociclib blocks the transcriptional activity of p53 in an ATM-dependent-fashion after ionizing radiation exposure, as the blockage of p21/WAF1 expression demonstrates. These observations are a proof of concept for a more selective therapy, based on the combination of CDK4/6 inhibition and radiotherapy, which would only benefit to those patients with a functional p53 pathway.

The orthogeriatric comanagement improves clinical outcomes of hip fracture in older adults.

Treatment of older adults with hip fracture is a healthcare challenge. Orthogeriatric comanagement that is an integrated model of care with shared responsibility improves time to surgery and reduces the length of hospital stay and mortality compared with orthopedic care with geriatric consultation service and usual orthopedic care, respectively. INTRODUCTION: Treatment of fractures in older adults is a clinical challenge due partly to the presence of comorbidity and polypharmacy. The goal of orthogeriatric models of care is to improve clinical outcomes among older people with hip fractures. We compare clinical outcomes of persons with hip fracture cared according to orthogeriatric comanagement (OGC), orthopedic team with the support of a geriatric consultant service (GCS), and usual orthopedic care (UOC). METHODS: This is a single-center, pre-post intervention observational study with two parallel arms, OGC and GCS, and a retrospective control arm. Hip fracture patients admitted to the trauma ward were assigned by the orthopedic surgeon to the OGC (n = 112) or GCS (n = 108) group. The intervention groups were compared each with others and both with the retrospective control group (n = 210) of older adults with hip fracture. Several clinical indicators are considered, including time to surgery, length of stay, in-hospital, and 1-year mortality. RESULTS: Patients in the OGC (OR 2.62; CI 95% 1.40-4.91) but not those in the GCS (OR 0.74; CI 95% 0.38-1.47) showed a higher probability of undergoing surgery within 48 h compared with those in the UOC. Moreover, the OGC (ß, - 1.08; SE, 0.54, p = 0.045) but not the GCS (ß, - 0.79; SE, 0.53, p = 0.148) was inversely associated with LOS. Ultimately, patients in the OGC (OR 0.31; CI 95 % 0.10-0.96) but not those in the GCS (OR 0.37; CI 95% 0.10-1.38) experienced a significantly lower 1-year mortality rate compared with those in the UOC. All analyses were independent of several confounders. CONCLUSIONS: Older adults with hip fracture taken in care by the OGC showed better clinical indicators, including time to surgery, length of stay and mortality, than those managed by geriatric consultant service or usual orthopedic care.

Blockage of autophagic flux is associated with lymphocytosis and higher percentage of tumoral cells in chronic lymphocytic leukemia of B cells.

PURPOSE: Autophagy has lately emerged as an important biological process with implications in several hematological pathologies. Recently, a growing body of evidence supports a putative role of autophagy in chronic lymphocytic leukemia; however, no definitive clue has been established so far. To elucidate this issue, we have developed a pilot study to measure autophagic flux in peripheral blood mononuclear cells from chronic lymphocytic leukemia patients, and explored its correlation with classical clinical/analytical parameters. METHODS/PATIENTS: Thirty-three chronic lymphocytic leukemia patients participated in the study. Autophagic flux in peripheral blood mononuclear cells was determined by western blot measuring the levels of the proteins p62 and lipidated LC3. Moreover, p62 mRNA levels were analyzed by RT-qPCR. RESULTS: Lymphocytosis and the percentage of tumoral lymphocytes in chronic lymphocytic leukemia patients statistically correlate with a blocked autophagic flux. CONCLUSION: Alterations in autophagic flux could play an important role in the physiopathology of chronic lymphocytic leukemia.

Dietary intake and major food sources of polyphenols in people with type 2 diabetes: The TOSCA.IT Study.

PURPOSE: Proper evaluation of polyphenols intake at the population level is a necessary step in order to establish possible associations with health outcomes. Available data are limited, and so far no study has been performed in people with diabetes. The aim of this work was to document the intake of polyphenols and their major food sources in a cohort of people with type 2 diabetes and in socio-demographic subgroups. METHODS: We studied 2573 men and women aged 50-75 years. Among others, anthropometry was measured by standard protocol and dietary habits were investigated by food frequency questionnaire (EPIC). The intake of polyphenols was evaluated using US Department of Agriculture and Phenol-Explorer databases. RESULTS: The mean total polyphenol intake was 683.3 ± 5.8 mg/day. Non-alcoholic beverages represented the main food source of dietary polyphenols and provided 35.5% of total polyphenol intake, followed by fruits (23.0%), alcoholic beverages (14.0%), vegetables (12.4%), cereal products and tubers (4.6%), legumes (3.7%) and oils (2.1%); chocolate, cakes and nuts are negligible sources of polyphenols in this cohort. The two most important polyphenol classes contributing to the total intake were flavonoids (47.5%) and phenolic acids (47.4%). Polyphenol intake increased with age and education level and decreased with BMI; furthermore, in the northern regions of Italy, the polyphenol intake was slightly, but significantly higher than in the central or southern regions. CONCLUSIONS: The study documents for the first time the intake of polyphenols and their main food sources in people with diabetes using validated and complete databases of the polyphenol content of food. Compared with published data, collected in people without diabetes, these results suggest a lower intake and a different pattern of intake in people with diabetes.

Human Mesenchymal Stem Cells Growth and Osteogenic Differentiation on Piezoelectric Poly(vinylidene fluoride) Microsphere Substrates.

The aim of this work was to determine the influence of the biomaterial environment on human mesenchymal stem cell (hMSC) fate when cultured in supports with varying topography. Poly(vinylidene fluoride) (PVDF) culture supports were prepared with structures ranging between 2D and 3D, based on PVDF films on which PVDF microspheres were deposited with varying surface density. Maintenance of multipotentiality when cultured in expansion medium was studied by flow cytometry monitoring the expression of characteristic hMSCs markers, and revealed that cells were losing their characteristic surface markers on these supports. Cell morphology was assessed by scanning electron microscopy (SEM). Alkaline phosphatase activity was also assessed after seven days of culture on expansion medium. On the other hand, osteoblastic differentiation was monitored while culturing in osteogenic medium after cells reached confluence. Osteocalcin immunocytochemistry and alizarin red assays were performed. We show that flow cytometry is a suitable technique for the study of the differentiation of hMSC seeded onto biomaterials, giving a quantitative reliable analysis of hMSC-associated markers. We also show that electrosprayed piezoelectric poly(vinylidene fluoride) is a suitable support for tissue engineering purposes, as hMSCs can proliferate, be viable and undergo osteogenic differentiation when chemically stimulated.

SOX9 protein is stabilized by TGF-ß and regulates PAPSS2 mRNA expression in chondrocytes.

OBJECTIVE: We previously identified 3'-phosphoadenosine 5'-phosphosulfate synthase 2 (PAPSS2) as a transcriptional target of transforming growth factor ß (TGF-ß) in chondrocytes. PAPSS2 is required for proper sulfation of proteoglycans in cartilage. Defective sulfation in the matrix results in alterations in mechanical properties of the cartilage that would be expected to result in degeneration. The objective of this study was to identify factors that regulate PAPSS2 expression and compare to a known TGF-ß responsive gene, proteoglycan 4/lubricin (PRG4). In this study, TGF-ß-mediated regulation of SOX9 was characterized, and the involvement of SOX9 in regulation of PAPSS2 mRNA was investigated. DESIGN: Primary bovine articular chondrocytes grown in micromass culture and ATDC5 cells were used as the model system. Adenoviruses were used to express SOX9 and SMAD3. siRNA was used to knock-down Sox9 and Smad3. Western blot and real-time quantitative RT-PCR (qPCR) were used to measure changes in protein and mRNA levels in response to treatment. RESULTS: Over-expression of SOX9 was sufficient to up-regulate PAPSS2 mRNA. TGF-ß treatment of SOX9-expressing cells resulted in enhanced up-regulation of PAPSS2 mRNA, suggesting that SOX9 cooperates with TGF-ß signaling. Furthermore, Sox9 was required for full TGF-ß-mediated induction of Papss2. In contrast, PRG4 was regulated by SMAD3 but not SOX9. SOX9 protein levels were increased after treatment with TGF-ß, although SOX9 mRNA was not. SOX9 protein was post-translationally stabilized after treatment with TGF-ß. CONCLUSIONS: TGF-ß stabilizes SOX9 protein, and SOX9 is sufficient and necessary for TGF-ß-mediated regulation of PAPSS2 mRNA, providing a novel mechanism for TGF-ß-mediated gene regulation in chondrocytes.

Estrogen Receptors and Chronic Venous Disease.

OBJECTIVE/BACKGROUND: Chronic venous disease (CVD) is a common and relevant problem affecting Western people. The role of estrogens and their receptors in the venous wall seems to support the major prevalence of CVD in women. The effects of the estrogens are mediated by three estrogen receptors (ERs): ERα, ERß, and G protein-coupled ER (GPER). The expression of ERs in the vessel walls of varicose veins is evaluated. METHODS: In this prospective study, patients of both sexes, with CVD and varicose veins undergoing open venous surgery procedures, were enrolled in order to obtain vein samples. To obtain control samples of healthy veins, patients of both sexes without CVD undergoing coronary artery bypass grafting with autologous saphenous vein were recruited (control group). Samples were processed in order to evaluate gene expression. RESULTS: Forty patients with CVD (10 men [25%], 30 women [75%], mean age 54.3 years [median 52 years, range 33-74 years]) were enrolled. Five patients without CVD (three men, two women [aged 61-73 years]) were enrolled as the control group. A significant increase of tissue expression of ERα, ERß and GPER in patients with CVD was recorded (p < .01), which was also related to the severity of venous disease. CONCLUSION: ERs seem to play a role in CVD; in this study, the expression of ERs correlated with the severity of the disease, and their expression was correlated with the clinical stage.

Surgical complications of carotid body tumors surgery: a review.

Carotid body tumor (CBT) is a rare neoplasm, although it represents about 65% of head and neck paragangliomas. Surgical excision is considered the appropriate therapy for CBTs. The aim of this study was to evaluate surgical outcomes on a large scale. We reviewed 19 studies between 2004 to 2014 with a total of 625 procedures. We observed a higher number of cases in women (62%). Only 3 (0,48%) deaths were reported as surgical complication. Total cranial nerve injuries were 302 (48,32%) of which 194 (31,04%) were transient and 108 (17,28%) were permanent. We found a total of 174 (27,84%) arterial injuries, most of which are external carotid artery (ECA) injuries. Cerebrovascular accident due to surgery were 15 (2,4%). We concluded that surgical resection remains the treatment of choice for these disease despite the related morbidity.

Monitoring hypnotic effect and nociception with two EEG-derived indices, qCON and qNOX, during general anaesthesia.

BACKGROUND: The objective of the present study was to validate the qCON index of hypnotic effect and the qNOX index of nociception. Both indices are derived from the frontal electroencephalogram (EEG) and implemented in the qCON 2000 monitor (Quantium Medical, Barcelona, Spain). METHODS: The study was approved by the local ethics committee, including data from 60 patients scheduled for ambulatory surgery undergoing general anaesthesia with propofol and remifentanil, using TCI. The Bis (Covidien, Boulder, CO, USA) was recorded simultaneously with the qCON. Loss of eyelash reflex [loss of consciousness (LOC)] was recorded, and prediction probability for Bis and qCON was calculated. Movement as a response to noxious stimulation [laryngeal mask airway (LMA) insertion, laryngoscopy and tracheal intubation] was registered. The correlation coefficient between qCON and Bis was calculated. The patients were divided into movers/non-movers as a response to noxious stimulation. A paired t-test was used to assess significant difference for qCON and qNOX for movers/non-movers. RESULTS: The prediction probability (Pk) and the standard error (SE) for qCON and Bis for detecting LOC was 0.92 (0.02) and 0.94 (0.02) respectively (t-test, no significant difference). The R between qCON and Bis was 0.85. During the general anaesthesia (Ce propofol > 2 µg/ml, Ce remifentanil > 2 ng/ml), the mean value and standard deviation (SD) for qCON was 45 (8), while for qNOX it was 40 (6). The qNOX pre-stimuli values were significantly different (P < 0.05) for movers/non-movers as a response to LMA insertion [62.5 (24.0) vs. 45.5 (24.1)], tracheal intubation [58.7 (21.8) vs. 41.4 (20.9)], laryngoscopy [54.1 (21.4) vs. 41.0 (20.8)]. There were no significant differences in remifentanil or propofol effect-site concentrations for movers vs. non-movers. CONCLUSION: The qCON was able to reliably detect LOC during general anaesthesia with propofol and remifentanil. The qNOX showed significant overlap between movers and non-movers, but it was able to predict whether or not the patient would move as a response to noxious stimulation, although the anaesthetic concentrations were similar.

Trichoderma species fungemia after high-dose chemotherapy and autologous stem cell transplantation: a case report.

We present a case of Trichoderma fungemia with pulmonary involvement in a multiple myeloma patient, who was severely immunocompromised and heavily treated with high-dose melphalan, and underwent autologous hematopoietic cell transplantation. This is the first report, to our knowledge, of proven Trichoderma fungemia, defined by published criteria, successfully treated with voriconazole.

Influencia de la apariencia de las mamas en la calidad de vida: diferencias entre población preoperatoria de mamoplastía de reducción y población control / Criterion validity of a questionnaire to assess quality of life associated to the appearance of breasts in women

Objetivo: El Breast Q Reduction and Mastopexy Module es un instrumento específico para la evaluación de calidad de vida asociado a mamas desde la perspectiva del paciente, recientemente validado para uso en español en Chile. Cuenta con evaluación pre y postoperatoria. El objetivo del presente estudio es conocer la validez de criterio al comparar las distribuciones en distintas poblaciones de individuos así como la diferencia del puntaje entre el pre y postoperatorio. Materiales y Métodos: El instrumento validado en español Breast Q Reduction-Mastopexy Module fue sometido a prueba para evaluar su validez de criterio comparando los resultados de la escala en pacientes que deseaban someterse a cirugía versus 2 grupos control, uno de pacientes hospitalizados por otra causa y otro de estudiantes de medicina. Resultados: Se aplicó la encuesta a 46 mujeres, 6 pacientes preoperatorios de mamoplastía de reducción, 20 alumnas de medicina y 20 pacientes hospitalizadas por otra causa. Hubo diferencias estadísticamente significativas entre las pacientes y los grupos control en los dominios autoimagen corporal (p = 0,0001), desempeño social (p = 0,0035) y síntomas físicos (p = 0,0058), no se observaron diferencias en el dominio de sexualidad (p = 0,1432), sin embargo, sólo 4/6 pacientes contestaron la encuesta ya que las otras 2 declararon no tener vida sexual. Conclusiones: Estos resultados preliminares sugieren que la versión en español del Breast Q Reduction-Mastopexy Module es un instrumento útil para evaluar calidad de vida asociada a las mamas en mujeres chilenas.

Background: The Breast QoL Reduction and Mastopexy Module assesses quality of life associated to breast appearance from the point of view of the patient. Its Spanish version was recently validated in Chile. Aim: To assess the criterion validity of the instrument applying it in different populations of women and in the pre and post-operative periods. Material and Methods: The questionnaire was applied to six women subjected to reduction mammoplasty in the pre and post-operative period. It was also applied to 20 women hospitalized for other causes and 20 female medical students. Results: There were significant differences between operated women and their non-operated counterparts in the domains body self-image, social performance and physical symptoms. No differences in sexuality were found. However this last question was answered only by four operated patients, since two declared not to have sex life. Conclusions: The questionnaire is useful to assess quality of life associated to the appearance of breasts.

Systemic inflammation is related to coronary microvascular dysfunction in obese patients without obstructive coronary disease.

BACKGROUND AND AIMS: Obesity, systemic inflammation and changes in the heart functions are associated with increased cardiovascular risk. This study aimed to investigate coronary microvascular dysfunction as an early marker of atherosclerosis in obese patients without any evidence of cardiovascular disease. METHODS AND RESULTS: 86 obese subjects (aged 44 ± 12 years, body mass index (BMI) 41 ± 8 kg m(-2)), without evidence of heart disease, and 48 lean controls were studied using transthoracic Doppler echocardiography for detecting coronary flow reserve (CFR). A value of CFR ≤ 2.5 was considered abnormal. We measured interleukin-6 (IL-6), tumour necrosis factor-α (TNF-α) and adiponectin in all patients. Patients with abnormal CFR underwent coronary multislice computed tomography (MSCT) in order to exclude an epicardial stenosis. CFR in obese subjects was lower than in lean subjects (3.2 ± 0.8 vs. 3.7 ± 0.7, p = 0.02) and was abnormal in 27 (31%) obese patients and in one (2%) control (p < 0.0001). All subjects with abnormal CFR showed no coronary stenosis at MSCT. At multivariable analysis, IL-6 and TNF-α were the only determinants of CFR (p < 0.02 and p < 0.02, respectively). At multivariable logistic regression analysis, IL-6 and TNF-α were the only determinants of CFR ≤ 2.5 (p < 0.03 and p < 0.03, respectively). CONCLUSIONS: CFR is often reduced in obese subjects without clinical evidence of heart disease, suggesting a coronary microvascular impairment. This microvascular dysfunction seems to be related to a chronic inflammation mediated by adipocytokines. Our findings may explain the increased cardiovascular risk in obesity, independently of BMI.

Increased inflammatory biomarkers in early pregnancy is associated with the development of pre-eclampsia in patients with periodontitis: a case control study.

AIM(S): To explore the relationship between biomarkers of systemic inflammation in plasma and gingival crevicular fluid in early pregnancy and the subsequent development of pre-eclampsia in patients with periodontitis. MATERIALS AND METHODS: A case-control study was performed. From a cohort composed of 126 pregnant women, 43 normotensive healthy pregnant women were randomly selected, and 11 cases of preeclampsia were identified. Plasmatic and gingival crevicular fluid (GCF) samples were collected in early pregnancy (11-14 wk gestation). The levels of interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α) were measured in the plasma and GCF samples, whereas the level of C-reactive protein (CRP) was measured in plasma samples. Biomarkers were determined by ELISA assays. The data were analysed using descriptive statistics, and the association between variables was estimated through logistic regression models. RESULTS: There was observed an association between pre-eclampsia and plasmatic levels of CRP (OR: 1.07; p = 0.003). Additionally, pre-eclampsia also was associated with IL-6 levels in GCF samples in early pregnancy (OR: 1.05; p = 0.039). A multiple logistic regression model suggests that increased levels of IL-6 in GCF (OR = 1.06; p = 0.02; CI 95% 1.007-1.117) in early pregnancy increase the risk of developing pre-eclampsia. CONCLUSION(S): Pregnant women with periodontitis who later development pre-eclampsia, shows increased levels of IL-6 in GCF and CRP in plasma during early pregnancy. Periodontal disease could contribute to systemic inflammation in early pregnancy via a local increase of IL-6 and the systemic elevation of CRP. Therefore, both inflammatory markers could be involved in the relationship between periodontal disease and pre-eclampsia.

Blood stream infections after allogeneic stem cell transplantation: a single-center experience with the use of levofloxacin prophylaxis.

Blood stream infections (BSIs) remain one of the major causes of morbidity and mortality for patients receiving an allogeneic hematopoietic stem cell transplantation (HSCT). In the present study, we evaluated the incidence and characteristics of BSI within 1 year after allogeneic HSCT in 269 consecutive adult patients who received antibacterial prophylaxis with levofloxacin. Cumulative incidence of BSI was 12% (95% confidence interval, 8-16%). Bacteria were responsible for 30 out of the 32 BSI, while fungi were responsible for 2 episodes of BSI. The median onset of BSI was day 8 (range 1-328 days) post transplant, and 66% of BSI occurred before neutrophil recovery. Gram-positive organisms accounted for 60% (n=18) of bacteremia, and gram-negative isolates for 40% (n=12) of the cases. Coagulase-negative staphylococci were the most commonly isolated gram-positive pathogens (53% of the cases), while Escherichia coli was the most commonly isolated gram-negative bacteria (58% of the cases). Candida albicans and Candida guillermondii were isolated from patients with candidemia. Resistance to fluoroquinolones (FQ) was common with 13% of gram-positive isolates being susceptible to FQ, while 50% of the gram-negative rods were susceptible to FQ. Crude mortality and mortality attributable to BSI were both 3% (1 of 32). In conclusion, our data suggest that despite the emergence of antibiotic resistance, FQ prophylaxis may be considered an appealing approach in allogeneic HSCT recipients and is also worth evaluating in randomized studies.

Immune effects of polychlorinated biphenyls, smoking and alcohol.

Polychlorinated biphenyls (PCB) have been shown to exert some immune effects. Here we analysed their effects also on immune parameters not previously studied such as TCR alpha-beta, TCR gamma-delta and regulatory T cells (Treg), taking into account the specific and cumulative interference of smoking and alcohol. The study subjects consisted of 26 male workers in a steel works factory, employed in the electrical maintenance sector, with previous exposure to a mixture of PCB (exposed subjects), and 30 male workers with no occupational exposure to PCB (controls). All subjects were given a questionnaire and peripheral venous blood samples were taken to determine serum PCB (33 congeners), total cholesterol and triglycerides, leukocytes, total lymphocytes and the T lymphocyte subpopulations (TCR alpha-beta, TCRgamma-delta, CD4+ and Treg lymphocytes). PCB, even though at a very low concentration, were significantly higher in exposed subjects than controls, and were significantly correlated with age. Monocytes% and CD4+ were significantly reduced in the exposed subjects as compared to the controls. The serum concentration of PCB positively correlated with TCR alpha-beta, and negatively with TCRgamma-delta. Treg lymphocytes showed a positive dependence on tobacco smoking, while the monocytes percentage and CD4+ showed a negative and positive dependence, respectively, on alcohol intake. Our results seem to show some effects of slight exposure to PCB in particular reducing the relative concentration of TCRgamma-delta. This effect can favour indirectly the increase in Treg induced by smoking, the anti-inflammatory or proinflammatory/fibrogenetic/angiogenetic effect of which, exerted by produced cytokines, particularly TGF-beta, deserves further clarification.

Depletion of primary cilia in articular chondrocytes results in reduced Gli3 repressor to activator ratio, increased Hedgehog signaling, and symptoms of early osteoarthritis.

OBJECTIVE: Primary cilia are present in almost every cell type including chondrocytes. Studies have shown that defects in primary cilia result in skeletal dysplasia. The purpose of this study was to understand how loss of primary cilia affects articular cartilage. DESIGN: Ift88 encodes a protein that is required for intraflagellar transport and formation of primary cilia. In this study, we used Col2aCre;Ift88(fl/fl) transgenic mice in which primary cilia were deleted in chondrocytes. Col2aCre;Ift88(fl/fl) articular cartilage was characterized by histological staining, real time RT-PCR, and microindentation. Hedgehog (Hh) signaling was measured by expression of Ptch1 and Gli1 mRNA. The levels of Gli3 proteins were determined by western blot. RESULTS: Col2aCre;Ift88(fl/fl) articular cartilage was thicker and had increased cell density, likely due to decreased apoptosis during cartilage remodeling. Mutant articular cartilage also showed increased expression of osteoarthritis (OA) markers including Mmp13, Adamts5, ColX, and Runx2. OA was also evident by reduced stiffness in mutant cartilage as measured by microindentation. Up-regulation of Hh signaling, which has been associated with OA, was present in mutant articular cartilage as measured by expression of Ptch1 and Gli1. Col2aCre;Ift88(fl/fl) cartilage also demonstrated reduced Gli3 repressor to activator ratio. CONCLUSION: Our results indicate that primary cilia are required for normal development and maintenance of articular cartilage. It was shown that primary cilia are required for processing full length Gli3 to the truncated repressor form. We propose that OA symptoms in Col2aCre;Ift88(fl/fl) cartilage are due to reduced Hh signal repression by Gli3.

Roles of the primary cilium component Polaris in synchondrosis development.

Primary cilia regulate several developmental processes and mediate hedgehog signaling. To study their roles in cranial base development, we created conditional mouse mutants deficient in Polaris, a critical primary cilium component, in cartilage. Mutant post-natal cranial bases were deformed, and their synchondrosis growth plates were disorganized. Expression of Indian hedgehog, Patched-1, collagen X, and MMP-13 was reduced and accompanied by decreases in endochondral bone. Interestingly, there was excessive intramembranous ossification along the perichondrium, accompanied by excessive Patched-1 expression, suggesting that Ihh distribution was wider and responsible for such excessive response. Indeed, expression of heparan sulfate proteoglycans (HS-PGs), normally involved in restricting hedgehog distribution, was barely detectable in mutant synchondroses. Analyses of the data provides further evidence for the essential roles of primary cilia and hedgehog signaling in cranial base development and chondrocyte maturation, and point to a close interdependence between cilia and HS-PGs to delimit targets of hedgehog action in synchondroses.