Author Correction: Epigallocatechin gallate, folic acid, vitamin B12, and hyaluronic acid significantly increase apoptosis and p53 expression in HeLa cells.

Correction to: Eur Rev Med Pharmacol Sci 2023; 27 (11): 5240-5245-DOI: 10.26355/eurrev_202306_32642-PMID: 37318498-published online on June 13, 2023. After publication, the authors discovered that Prof. C. Gentili's affiliation was wrong as he has never been a member of the Italian Society of Colposcopy and Cervicovaginal Pathology (SICPCV). The authors never found the mistake during the review process nor requested a correction before publication. Therefore, the second affiliation has been corrected as follows: Pathologist, Independent Practitioner, Carrara, Italy. There are amendments to this paper. The Publisher apologizes for any inconvenience this may cause. https://www.europeanreview.org/article/32642.

The co-creation, initial piloting, and protocol for a cluster randomised controlled trial of a coach-led positive body image intervention for girls in sport.

BACKGROUND: Globally, girls disengage from sports at an earlier age and higher rate than boys. This is, in part, due to the unique body image challenges that girls face, relative to their male peers. Existing intervention efforts that aim to reduce girls' negative body image and movement experiences have proven marginally effective, if not ineffective. This paper outlines the co-creation, initial piloting and protocol for a cluster randomised controlled trial of Body Confident Athletes (BCA); an in-person, coach-led intervention that aims to foster positive body image and sports enjoyment among girls. METHODS: Following co-creation and an initial pilot, a two-armed cluster randomised controlled trial will assess the immediate (post-intervention) and short-term (1-month and 3-month follow-up) impact of BCA on girls' (N = 1,036; 11-17 years old) body image, sports enjoyment, and affect. Sport organisations will be randomly allocated (1:1) into either an intervention or waitlist control condition. Girls and coaches in the intervention condition will complete three 60-minute sessions over three consecutive weeks. The primary outcome will be the immediate change in girls' body esteem, with secondary outcomes assessing the immediate and short-term changes in girls' body appreciation, self-objectification, attuned self-care, sports enjoyment, and affect. DISCUSSION: This research is the first to utilise an international multi-stakeholder partnership to co-create and evaluate an intervention that addresses the intersection of girls' body image and sport experiences. The theoretical and methodological considerations of this research have led to a feasible intervention and trial protocol, and if proven effective, BCA may assist in reducing the global gender disparity in sports participation. TRIAL REGISTRATION NUMBER: NCT05594524 , registered 25th October 2022.

Epigallocatechin gallate, folic acid, vitamin B12, and hyaluronic acid significantly increase apoptosis and p53 expression in HeLa cells.

OBJECTIVE: The human papilloma virus (HPV) is the etiological agent of cervical cancer in more than 95% of cases worldwide. Although most HPV infections clear up on their own and most pre-cancerous lesions spontaneously resolve, in some cases, they can persist, leading to lesions which may progress towards invasive cervical cancer. MATERIALS AND METHODS: We evaluated the effects of the association of epigallocatechin gallate (EGCG) + folic acid (FA) + vitamin B12 (B12) + hyaluronic acid (HA) on HPV-positive cervical cancer cells (HeLa). RESULTS: The association of EGCG + FA + B12 + HA induced a significant increase of apoptosis and p53 gene expression with a concomitant decrease of E6/E7 gene expression, a marker of HPV infection. CONCLUSIONS: This study provides for the first-time evidence on the potential additive activity of EGCG + FA + B12 + HA in counteracting HPV infection, by increasing apoptosis and p53 expression in HPV-infected cervical HeLa cells.

Classifying subclinical depression using EEG spectral and connectivity measures.

Detecting depression on its early stages helps preventing the onset of severe depressive episodes. In this study, we propose an automatic classification pipeline to detect subclinical depression (i.e., dysphoria) through the electroencephalography (EEG) signal. To this aim, we recorded the EEG signals in resting condition from 26 female participants with dysphoria and 38 female controls. The EEG signals were processed to extract several spectral and functional connectivity features to feed a nonlinear Support Vector Machine (SVM) classifier embedded with a Recursive Feature Elimination (RFE) algorithm. Our recognition pipeline obtained a maximum classification accuracy of 83.91% in recognizing dysphoria patients with a combination of connectivity and spectral measures. Moreover, an accuracy of 76.11% was achieved with only the 4 most informative functional connections, suggesting a central role of cortical connectivity in the theta band for early depression recognition. The present study can facilitate the diagnosis of subclinical conditions of depression and may provide reliable indicators of depression for the clinical community.

The effects of cognitive and behavioural therapies for anxiety disorders on depression: a meta-analysis.

BACKGROUND: The effects of cognitive behavioural therapy of anxiety disorders on depression has been examined in previous meta-analyses, suggesting that these treatments have considerable effects on depression. In the current meta-analysis we examined whether the effects of treatments of anxiety disorders on depression differ across generalized anxiety disorder (GAD), social anxiety disorder (SAD) and panic disorder (PD). We also compared the effects of these treatments with the effects of cognitive and behavioural therapies of major depression (MDD). METHOD: We searched PubMed, PsycINFO, EMBASE and the Cochrane database, and included 47 trials on anxiety disorders and 34 trials on MDD. RESULTS: Baseline depression severity was somewhat lower in anxiety disorders than in MDD, but still mild to moderate in most studies. Baseline severity differed across the three anxiety disorders. The effect sizes found for treatment of the anxiety disorders ranged from g = 0.47 for PD, g = 0.68 for GAD and g = 0.69 for SAD. Differences between these effect sizes and those found in the treatment of MDD (g = 0.81) were not significant in most analyses and we found few indications that the effects differed across anxiety disorders. We did find that within-group effect sizes resulted in significantly (p < 0.001) larger effect sizes for depression (g = 1.50) than anxiety disorders (g = 0.73-0.91). Risk of bias was considerable in the majority of studies. CONCLUSIONS: Patients participating in trials of cognitive behavioural therapy for anxiety disorders have high levels of depression. These treatments have considerable effects on depression, and these effects are comparable to those of treatment of primary MDD.

Combining electroencephalographic activity and instantaneous heart rate for assessing brain-heart dynamics during visual emotional elicitation in healthy subjects.

Emotion perception, occurring in brain areas such as the prefrontal cortex and amygdala, involves autonomic responses affecting cardiovascular dynamics. However, how such brain-heart dynamics is further modulated by emotional valence (pleasantness/unpleasantness), also considering different arousing levels (the intensity of the emotional stimuli), is still unknown. To this extent, we combined electroencephalographic (EEG) dynamics and instantaneous heart rate estimates to study emotional processing in healthy subjects. Twenty-two healthy volunteers were elicited through affective pictures gathered from the International Affective Picture System. The experimental protocol foresaw 110 pictures, each of which lasted 10 s, associated to 25 different combinations of arousal and valence levels, including neutral elicitations. EEG data were processed using short-time Fourier transforms to obtain time-varying maps of cortical activation, whereas the associated instantaneous cardiovascular dynamics was estimated in the time and frequency domains through inhomogeneous point-process models. Brain-heart linear and nonlinear coupling was estimated through the maximal information coefficient (MIC). Considering EEG oscillations in theθband (4-8 Hz), MIC highlighted significant arousal-dependent changes between positive and negative stimuli, especially occurring at intermediate arousing levels through the prefrontal cortex interplay. Moreover, high arousing elicitations seem to mitigate changes in brain-heart dynamics in response to pleasant/unpleasant visual elicitation.

Brain-heart linear and nonlinear dynamics during visual emotional elicitation in healthy subjects.

This study investigates brain-heart dynamics during visual emotional elicitation in healthy subjects through linear and nonlinear coupling measures of EEG spectrogram and instantaneous heart rate estimates. To this extent, affective pictures including different combinations of arousal and valence levels, gathered from the International Affective Picture System, were administered to twenty-two healthy subjects. Time-varying maps of cortical activation were obtained through EEG spectral analysis, whereas the associated instantaneous heartbeat dynamics was estimated using inhomogeneous point-process linear models. Brain-Heart linear and nonlinear coupling was estimated through the Maximal Information Coefficient (MIC), considering EEG time-varying spectra and point-process estimates defined in the time and frequency domains. As a proof of concept, we here show preliminary results considering EEG oscillations in the θ band (4-8 Hz). This band, indeed, is known in the literature to be involved in emotional processes. MIC highlighted significant arousal-dependent changes, mediated by the prefrontal cortex interplay especially occurring at intermediate arousing levels. Furthermore, lower and higher arousing elicitations were associated to not significant brain-heart coupling changes in response to pleasant/unpleasant elicitations.

Brain connectivity is altered by extreme physical exercise during non-REM sleep and wakefulness: indications from EEG and fMRI studies.

Brain connectivity is associated to behavioral states (e.g. wake, sleep) and modified by physical activity although, to date, it is not clear which components (e.g. hypothalamus-pituitary-adrenal axis hormones, cytokines) associated to the exercise are involved. In this pilot study, we used extreme exercise (UltraTriathlon) as a model to investigate physical-activity-related changes of brain connectivity. We studied post-race brain synchronization during wakefulness and sleep as well as possible correlations between exercise-related cytokines/hormones and synchronization features. For wakefulness, global synchronization was evaluated by estimating from fMRI data (12 athletes) the brain global connectivity (GC). GC increased in several brain regions, mainly related to sensory-motor activity, emotional modulation and response to stress that may foster rapid exchange of information across regions, and reflect post-race internally-focused mental activity or disengagement from previous motor programs. No significant correlations between cytokines/hormones and GC were found. For sleep (8 athletes), synchronization was evaluated by estimating the local-(cortical) and global-related (thalamo- cortical) EEG features associated to the phenomenon of Sleep Slow Oscillations (SSO) of NREM sleep. Results showed that: power of fast rhythms in the baseline preceding the SSO increased in midline and parietal regions; amplitude and duration of SSOs increased, mainly in posterior areas; sigma modulation in the SSO up state decreased. In the post race, IL-10 positively correlated with fast rhythms baseline, SSO rate and positive slope; IL-1ra and cortisol inversely correlated with SSO duration; TNF-α and C-reactive protein positively correlated with fast rhythm modulation in the SSO up state. Sleep results suggest that: arousal during sleep, estimated by baseline fast rhythms, is increased; SSO may be sustained by cortical excitability, linked to anti-inflammatory markers (IL-10); thalamo-cortical entrainment, (sigma modulation), is impaired in athletes with higher inflammatory markers.

Point-process nonlinear autonomic assessment of depressive states in bipolar patients.

INTRODUCTION: This article is part of the Focus Theme of Methods of Information in Medicine on "Biosignal Interpretation: Advanced Methods for Studying Cardiovascular and Respiratory Systems". OBJECTIVES: The goal of this work is to apply a computational methodology able to characterize mood states in bipolar patients through instantaneous analysis of heartbeat dynamics. METHODS: A Point-Process-based Nonlinear Autoregressive Integrative (NARI) model is applied to analyze data collected from five bipolar patients (two males and three females, age 42.4 ± 10.5 range 32 -56) undergoing a dedicated affective elicitation protocol using images from the International Affective Picture System (IAPS) and Thematic Apperception Test (TAT). The study was designed within the European project PSYCHE (Personalised monitoring SYstems for Care in mental HEalth). RESULTS: RESULTS demonstrate that the inclusion of instantaneous higher order spectral (HOS) features estimated from the NARI nonlinear assessment significantly improves the accuracy in successfully recognizing specific mood states such as euthymia and depression with respect to results using only linear indices. In particular, a specificity of 74.44% using the instantaneous linear features set, and 99.56% using also the nonlinear feature set were achieved. Moreover, IAPS emotional elicitation resulted in a more discriminant procedure with respect to the TAT elicitation protocol. CONCLUSIONS: A significant pattern of instantaneous heartbeat features was found in depressive and euthymic states despite the inter-subject variability. The presented point-process Heart Rate Variability (HRV) nonlinear methodology provides a promising application in the field of mood assessment in bipolar patients.

Scaffold-assisted cartilage tissue engineering using infant chondrocytes from human hip cartilage.

OBJECTIVE: Studies about cartilage repair in the hip and infant chondrocytes are rare. The aim of our study was to evaluate the use of infant articular hip chondrocytes for tissue engineering of scaffold-assisted cartilage grafts. METHOD: Hip cartilage was obtained from five human donors (age 1-10 years). Expanded chondrocytes were cultured in polyglycolic acid (PGA)-fibrin scaffolds. De- and re-differentiation of chondrocytes were assessed by histological staining and gene expression analysis of typical chondrocytic marker genes. In vivo, cartilage matrix formation was assessed by histology after subcutaneous transplantation of chondrocyte-seeded PGA-fibrin scaffolds in immunocompromised mice. RESULTS: The donor tissue was heterogenous showing differentiated articular cartilage and non-differentiated tissue and considerable expression of type I and II collagens. Gene expression analysis showed repression of typical chondrocyte and/or mesenchymal marker genes during cell expansion, while markers were re-induced when expanded cells were cultured in PGA-fibrin scaffolds. Cartilage formation after subcutaneous transplantation of chondrocyte loaded PGA-fibrin scaffolds in nude mice was variable, with grafts showing resorption and host cell infiltration or formation of hyaline cartilage rich in type II collagen. Addition of human platelet rich plasma (PRP) to cartilage grafts resulted robustly in formation of hyaline-like cartilage that showed type II collagen and regions with type X collagen. CONCLUSION: These results suggest that culture of expanded and/or de-differentiated infant hip cartilage cells in PGA-fibrin scaffolds initiates chondrocyte re-differentiation. The heterogenous donor tissue containing immature chondrocytes bears the risk of cartilage repair failure in vivo, which may be possibly overcome by the addition of PRP.

Fatal case of human rabies imported to Italy from India highlights the importance of adequate post-exposure prophylaxis, October 2011.

In October 2011, an Indian man resident in Italy was admitted to a hospital in Mantua, Italy with symptoms of acute encephalitis. Due to a recent history of bite by a suspected rabid dog in India, where he had received incomplete post-exposure treatment, rabies was suspected. The patient died after 22 days of intensive care treatment and rabies was confirmed post mortem. This report stresses the need of appropriate post-exposure prophylaxis in rabies-endemic countries.

Novel injectable gel (system) as a vehicle for human articular chondrocytes in cartilage tissue regeneration.

We developed a novel injectable carrageenan/fibrin/hyaluronic acid-based hydrogel with in situ gelling properties to be seeded with chondrogenic cells and used for cartilage tissue engineering applications. We first analysed the distribution within the hydrogel construct and the phenotype of human articular chondrocytes (HACs) cultured for 3 weeks in vitro. We observed a statistically significant increase in the cell number during the first 2 weeks and maintenance of cell viability throughout the cell culture, together with the deposition/formation of a cartilage-specific extracellular matrix (ECM). Taking advantage of a new in vivo model that allows the integration between newly formed and preexisting cartilage in immunodeficient mice to be investigated, we showed that injectable hydrogel seeded with human articular chondrocytes was able to regenerate and repair an experimentally made lesion in bovine articular cartilage, thus demonstrating the potential of this novel cell delivery system for cartilage tissue engineering.

Endogenous erythropoietin and a single bolus of 40,000 IU of epoetin alpha do not protect the heart from ischaemia-reperfusion injury during extracorporeal circulation for cardiac surgery.

Erythropoietin (EPO) exerts a tissue-protective activity in several non-haematopoietic tissues such as heart, brain, spinal cord and muscle. We evaluated the relationship between pre-operative endogenous EPO blood levels and myocardial damage in patients undergoing cardiopulmonary bypass (CPB). Furthermore, we investigated whether pre-operative administration of a single bolus of 40,000 IU epoetin alpha (EPOalpha) would reduce troponin I or creatine kinase isoenzyme (CK-MB) after on-pump coronary artery bypass graft (CABG) surgery. Sixty-seven patients (45 CABG, 22 valvular surgery) were enrolled. EPO was measured in the pre-surgical period and correlated to post-surgical troponin I and CK-MB peaks. Subsequently, forty patients scheduled for CABG were randomized into two groups, receiving, respectively, a) standard medical and surgical treatment (20 patients) and b) the same treatment plus 40,000 IU of EPOalpha in a single bolus injection in the immediate pre-surgical period (20 patients). In our population, we did not find any correlation between pre-surgical EPO and post-surgical troponin I or CK-MB peaks (p Pearson > 0.05). Furthermore, patients treated with EPOalpha did not show differences compared to the control group in either troponin I (1.7+/-1.8 vs 2.6+/-3.4, p>0.05) or CK-MB (19.6 +/-13.2 vs 17.1+/-12.6, p>0.05) peaks measured in the post-surgical period.

Spatiotemporal dynamics of single-letter reading: a combined ERP-FMRI study.

This work investigates the neural correlates of single-letter reading by combining event-related potentials (ERPs) and functional magnetic resonance imaging (fMRI), thus exploiting their complementary spatiotemporal resolutions. Three externally-paced reading tasks were administered with an event-related design: passive observation of letters and symbols and active reading aloud of letters. ERP and fMRI data were separately recorded from 8 healthy adults during the same experimental conditions. Due to the presence of artifacts in the EEG signals, two subjects were discarded from further analysis. Independent Component Analysis was applied to ERPs, after dimensionality reduction by Principal Component Analysis: some independent components were clearly related to specific reading functions and the associated current density distributions in the brain were estimated with Low Resolution Electromagnetic Tomography Analysis method (LORETA). The impulse hemodynamic response function was modeled as a linear combination of linear B-spline functions and fMRI statistical analysis was performed by multiple linear regression. fMRI and LORETA maps were superimposed in order to identify the overlapping activations and the activated regions specifically revealed by each modality. The results showed the existence of neuronal networks functionally specific for letter processing and for explicit verbal-motor articulation, including the temporo-parietal and frontal regions. Overlap between fMRI and LORETA results was observed in the inferior temporal-middle occipital gyrus, suggesting that this area has a crucial and multifunctional role for linguistic and reading processes, likely because its spatial location and strong interconnection with the main visual and auditory sensory systems may have favored its specialization in grapheme-phoneme matching.

Tactile spatial working memory activates the dorsal extrastriate cortical pathway in congenitally blind individuals.

In sighted individuals, both the visual and tactile version of the same spatial working memory task elicited neural responses in the dorsal "where" cortical pathway (Ricciardi et al., 2006). Whether the neural response during the tactile working memory task is due to visually-based spatial imagery or rather reflects a more abstract, supramodal organization of the dorsal cortical pathway remains to be determined. To understand the role of visual experience on the functional organization of the dorsal cortical stream, using functional magnetic resonance imaging (fMRI) here we examined brain response in four individuals with congenital or early blindness and no visual recollection, while they performed the same tactile spatial working memory task, a one-back recognition of 2D and 3D matrices. The blind subjects showed a significant activation in bilateral posterior parietal cortex, dorsolateral and inferior prefrontal areas, precuneus, lateral occipital cortex, and cerebellum. Thus, dorsal occipito-parietal areas are involved in mental imagery dealing with spatial components in subjects without prior visual experience and in response to a non-visual task. These data indicate that recruitment of the dorsal cortical pathway in response to the tactile spatial working memory task is not mediated by visually-based imagery and that visual experience is not a prerequisite for the development of a more abstract functional organization of the dorsal stream. These findings, along with previous data indicating a similar supramodal functional organization within the ventral cortical pathway and the motion processing brain regions, may contribute to explain how individuals who are born deprived of sight are able to interact effectively with the surrounding world.

Alcohol consumption and heavy drinking: a survey in three Italian villages.

AIMS: We investigated drinking habits, and heavy and problem drinking prevalence in a sample of individuals attending the consulting rooms of local General Practitioners in three Italian villages. METHODS: The samples were selected to be representative of the entire population of the three villages. Information on alcohol-drinking patterns was collected using a questionnaire that included a masked form of the CAGE rating scale. According to the frequency of alcohol intake, subjects were grouped in three categories: abstainers, occasional drinkers, and daily drinkers. In agreement with WHO guidelines, 40 g/day for males and 20 g/day for females were taken as cut-off for 'heavy drinking' and consumptions of > 80 g/day for males and 40 g/day for females were used to define 'problem drinking'. RESULTS: A total of 2972 individuals were included in the survey (19% of the population). Of these, 44% were abstinent, 20% occasional drinkers, and 36% daily drinkers. Daily drinking was found to be more common in males than in females but heavy drinking was significantly higher in females compared with males (P > or = 0.0001). The problem drinkers were 12% of the entire population and the CAGE-positive subjects (> or = 2 positive answers) were 3.5%. CONCLUSIONS: Our data indicate that alcohol drinking is widely diffused in the three communities. A large layer of the population drinks above the WHO-established cut-off. The incidence of heavy and problem drinking seems to have significant gender and regional differences that are important to consider when planning effective prevention programmes.

Neural correlates of spatial working memory in humans: a functional magnetic resonance imaging study comparing visual and tactile processes.

Recent studies of neural correlates of working memory components have identified both low-level perceptual processes and higher-order supramodal mechanisms through which sensory information can be integrated and manipulated. In addition to the primary sensory cortices, working memory relies on a widely distributed neural system of higher-order association areas that includes posterior parietal and occipital areas, and on prefrontal cortex for maintaining and manipulating information. The present study was designed to determine brain patterns of neural response to the same spatial working memory task presented either visually or in a tactile format, and to evaluate the relationship between spatial processing in the visual and tactile sensory modalities. Brain activity during visual and tactile spatial working memory tasks was measured in six young right-handed healthy male volunteers by using functional magnetic resonance imaging. Results indicated that similar fronto-parietal networks were recruited during spatial information processing across the two sensory modalities-specifically the posterior parietal cortex, the dorsolateral prefrontal cortex and the anterior cingulate cortex. These findings provide a neurobiological support to behavioral observations by indicating that common cerebral regions subserve generation of higher order mental representations involved in working memory independently from a specific sensory modality.

Cholesterol secretion and homeostasis in chondrocytes: a liver X receptor and retinoid X receptor heterodimer mediates apolipoprotein A1 expression.

Cholesterol is required for chondrocyte differentiation and bone formation. Apolipoprotein A1 (apoA-1) plays a major role in lipoprotein clearance and cholesterol redistribution. We report here that apoA-1 is expressed during chondrocyte differentiation in vitro and in vivo. In differentiating chondrocytes, the expression of the liver X receptor (LXR) is modulated and its expression correlates to the expression of apoA-1. The expression of other LXR target genes related to cholesterol homeostasis such as ABCA1 cholesterol transporter and sterol regulatory element-binding protein 1 (SREBP1) is similarly regulated. Small molecule ligands activating either LXR or retinoid X receptor (RXR) lead to a dramatic increase in apoA-1 mRNA and protein expression in cultured chondrocytes. These ligands strongly induce ABCA1 cholesterol transporter expression and effectively mediate cholesterol efflux from hypertrophic chondrocytes. In addition, we report that, in the same cells, the ligands down modulate Serum Amyloid A expression induced by bacterial lipopolysaccharide. Our studies provide evidence that LXR/RXR mediate a fine regulation of cholesterol homeostasis in differentiating chondrocytes.

Acute phase lipocalin Ex-FABP is involved in heart development and cell survival.

Ex-FABP is an extracellular fatty acid binding protein, expressed during chicken embryo development in cartilage, muscle fibers, and blood granulocytes. Transfection of chondrocytes and myoblasts with anti-sense Ex-FABP cDNA results in inhibition of cell proliferation and apoptosis induction. Ex-FABP expression is dramatically enhanced by inflammatory stimuli and in pathological conditions. In this paper, by in situ whole mount and immunohistochemistry analysis we show that, at early developmental stage, Ex-FABP is diffuse in all tissues of chick embryos. Particularly high level of transcript and protein are expressed in the heart. During acute phase response (APR) induced by endotoxin LPS injection, a marked increase of Ex-FABP mRNA was observed in embryos, highest Ex-FABP expression being in heart and liver. To investigate in vivo the biological role of Ex-FABP, we have directly microinjected chicken embryos with antibody against Ex-FABP. Almost 70% of chicken embryos died and the target tissue was the heart. We detected in heart of the treated embryos a significant increase of apoptotic cells and high level of fatty acids. We propose that the accumulation of fatty acid, specific ligand of Ex-FABP, in the cell microenvironment is responsible of heart cell death, and we suggest that Ex-FABP may act as a survival protein by playing a role as scavenger for fatty acids.

Runx2 expression and action in chondrocytes are regulated by retinoid signaling and parathyroid hormone-related peptide (PTHrP).

OBJECTIVE: Runx2 (also known as Cbfa1) is a transcription factor required for chondrocyte maturation and osteoblast differentiation. While there is information on the regulation of its expression during osteogenesis, much less is known about it during cartilage maturation. Here we asked whether Runx2 expression and function are affected by retinoic acid (RA) and parathyroid hormone-related peptide (PTHrP), which represent an important stimulator and inhibitor of chondrocyte maturation, respectively. DESIGN: We first cloned and characterized Runx2 expressed by chick chondrocytes (cRunx2). We then constructed expression vectors of cRunx2 and a dominant-negative form (DN-cRunx2) and determined their effects on chondrocyte maturation in culture before and during retinoid and PTHrP treatment. RESULTS: cRunx2 showed similar transactivation activity to that of its mammalian counterparts although it has a very short QA domain and lacks a small portion of the PST domain. cRunx2 over-expression stimulated chondrocyte maturation, as indicated by increases in alkaline phosphatase activity (APase), mineralization, and type X collagen and MMP-13 expression, and by maintenance of Indian hedgehog (Ihh) expression. RA treatment stimulated cRunx2 gene expression and boosted its pro-maturation effects. PTHrP treatment blocked Runx2 expression and its pro-maturation effects. Over-expression of DN-cRunx2 inhibited maturation and even prevented RA from exerting its pro-maturation role. CONCLUSIONS: As previously indicated by mammalian studies, cRunx2 has chondrocyte pro-maturation activity. Its expression and roles are favorably modulated by retinoid signaling but are completely inhibited by PTHrP. A model integrating cRunx2 with PTHrP, Ihh and retinoid signaling and operating during skeletogenesis is proposed.