Surface modifications of titanium (Ti) bone implants can activate an osteogenic response and accelerate osseointegration after implantation. In this study, in vitro tests were performed to evaluate different titanium dioxide TiO2 modified surfaces, sandblasted, large grit, acid-etched implant surfaces and surfaces featuring nanotubular structures (nanopore diameters of 20 and 100nm) produced through potentiostatic anodization before and after subjecting them to covalent treatment for functionalization and subsequent coating with collagen type I (Col I). The physicochemical and morphological properties were evaluated using spectroscopy and microscopy, which confirmed the structural and biochemical modifications of the surfaces after coating with Col I. Studies with pre-osteoblastic MC3T3-E1 cells indicate improved cell adhesion and proliferation on surfaces coated with Col I, whereas cell viability remained similar for all evaluated surfaces. The results of alkaline phosphatase expression and activity, as well as a mineralization assay, demonstrated that surfaces coated with Col I acted positively on the osteogenic differentiation of the cells in comparison with the non-coated surfaces. Our findings suggest that, regardless of the previous modification of the TiO2 surface, the addition of a Col I coating presents a promising modification for bone implant applications.

In the dynamic landscape of scientific research, imaging core facilities are vital hubs propelling collaboration and innovation at the technology development and dissemination frontier. Here, we present a collaborative effort led by Global BioImaging (GBI), introducing international recommendations geared towards elevating the careers of Imaging Scientists in core facilities. Despite the critical role of Imaging Scientists in modern research ecosystems, challenges persist in recognising their value, aligning performance metrics and providing avenues for career progression and job security. The challenges encompass a mismatch between classic academic career paths and service-oriented roles, resulting in a lack of understanding regarding the value and impact of Imaging Scientists and core facilities and how to evaluate them properly. They further include challenges around sustainability, dedicated training opportunities and the recruitment and retention of talent. Structured across these interrelated sections, the recommendations within this publication aim to propose globally applicable solutions to navigate these challenges. These recommendations apply equally to colleagues working in other core facilities and research institutions through which access to technologies is facilitated and supported. This publication emphasises the pivotal role of Imaging Scientists in advancing research programs and presents a blueprint for fostering their career progression within institutions all around the world.

Objective Odontogenic myxoma (OM) occasionally responds poorly to surgical treatment. The MAPK pathway is constitutively activated in several neoplasms and we aimed to test if the MAPK pathway is activated in OM, in order to pave the way for an alternative therapy for aggressive and recurrent cases. Materials and methods The immunoexpression of phosphorylated ERK1/2 (pERK1/2) was assessed in OM. We established a 3D organotypic culture model for the in vitro study and patient-derived xenografts (PDX) in mice for the in vivo study. The MEK inhibitor U0126 was used to inhibit phosphorylation of ERK1/2 in the in vitro and in vivo models. Results All OM showed strong pERK1/2 immunoexpression, consistent with MAPK pathway activation. Treatment of the 3D culture with U0126 resulted in a reduced pERK1/2/ERK1/2 ratio. Consistent with the in vitro results, all PDX of animals treated with U0126 showed a decreased volume fold change compared with controls. Conclusions The MAPK pathway is activated in OM and its inhibition leads to tumor shrinkage in PDX and cell culture models. Clinical relevance Our results offer a pre-clinical frame for OM-targeted therapy. Further work is needed to determine if this initial finding holds clinical promise.

Introdução: Placas de silicone e injeções de triancinolona melhoram o tamanho dos queloides e das cicatrizes hipertróficas, além do eritema, da elasticidade e de sintomas como dor e prurido. Esses tratamentos nao sao invasivos, têm um bom custo-beneficio e são amplamente utilizados como terapia inicial para queloides e cicatrizes hipertróficas; entretanto, faltam estudos comparativos dos dois tratamentos. Objetivo: Comparar o uso de placas de silicone, triancinolona intralesional, e a combinação de ambas as modalidades terapêuticas, no tratamento de cicatrizes hipertróficas na mesma área anatômica e causadas pelo mesmo mecanismo de lesão. Métodos e Materiais: Em um estudo prospectivo, 12 pacientes com cicatrizes de esternotomia mediana foram randomizados em 3 grupos (4 pacientes em cada grupo): Grupo 1. injeções mensais de triancinolona; Grupo 2. uma combinação de placas de silicone e injeções de triancinolona e Grupo 3. placas de silicone. Os pacientes foram avaliados em consultas clínicas mensais com o uso da Escala de Vancouver e durômetro. Foram realizadas imunohistoquímica e microscopia confocal para os colágenos de tipos I e VI em amostras de cicatriz. Os grupos foram comparados com os testes de Kruskall-Wallis e Friedman com significância de p< 0.05. Resultados: Os três tratamentos mostraram-se eficazes na melhora das cicatrizes, conforme demonstrado pela redução nos parâmetros da Escala de Vancouver. Foi observada uma diferença entre os três grupos no tempo 2, quando a triancinolona mostrou-se menos eficaz. O grupo 2 apresentou melhora na pigmentação (p = 0,042). Os colágenos de tipos I e VI apresentaram aumento de fluorescência em toda a derme superficial e profunda nas lesões não-tratadas, que diminuiu após do tratamento. Apesar do número pequeno de pacientes, este foi o primeiro estudo prospectivo que comparou estas modalidades de tratamento de cicatrizes, evitando vieses frequentemente vistos em publicações sobre tratamentos de cicatrizes.

Introduction: Silicone dressings and Triamcinolone injections are known to improve keloids and hypertrophic scars size, erythema, flexibility, and symptoms such as pain and itching. These treatments are non-invasive, inexpensive, and widely used as first or second-line therapy; however, studies comparing them are still lacking. Objective: To compare silicone dressings, triamcinolone injections, and a combination group, to treat hypertrophic scars, at the same anatomical area, caused by the same mechanism of injury. Materials and methods: In a prospective study, 12 patients with median-sternotomy scars were randomized into 3 groups (n=4 patients each): group 1, monthly triamcinolone injections; group 2, a combination of silicone dressings and triamcinolone injections; and group 3, silicone dressings. Patients were evaluated in monthly clinical appointments using the Vancouver Scale and the durometer. Immunohistochemistry and confocal microscopy for collagen types I and VI were performed in scar samples. The groups were compared using Kruskal-Wallis and Friedman tests, with p<0,05 indicating significance. Results: The three treatments were effective in reducing the Vancouver scores. A difference between the three groups was observed at time 2 when triamcinolone was less effective. Group 2 showed an improvement on pigmentation (p = 0,042). Collagens types I and VI presented increased fluorescence throughout the superficial and deep dermis in untreated lesions, which decreased after the treatment. Although the number of patients is limited, this is the first prospective study addressing some of the major bias in scars treatment.

The effects of the renin–angiotensin system (RAS) on stem cells isolated from human dental apical papilla (SCAPs) are completely unknown. Therefore, the aim of this study was to identify RAS components expressed in SCAPs and the effects of angiotensin (Ang) II and Ang‐(1–7) on cell proliferation. SCAPs were collected from third molar teeth of adolescents and maintained in cell culture. Messenger RNA expression and protein levels of angiotensin‐converting enzyme (ACE), ACE2, and Mas, Ang II type I (AT1) and type II (AT2) receptors were detected in SCAPs. Treatment with either Ang II or Ang‐(1–7) increased the proliferation of SCAPs. These effects were inhibited by PD123319, an AT2 antagonist. While Ang II augmented mTOR phosphorylation, Ang‐(1–7) induced ERK1/2 phosphorylation. In conclusion, SCAPs produce the main RAS components and both Ang II and Ang‐(1–7) treatments induced cell proliferation mediated by AT2 activation through different intracellular mechanisms.

Cancer-Associated Fibroblasts (CAFs) contribute to tumour progression and have received significant attention as a therapeutic target. These cells produce growth factors, cytokines and chemokines, stimulating cancer cell proliferation and inhibiting their apoptosis. Recent advances in drug delivery have demonstrated a significant promise of iron oxide nanoparticles in clinics as theranostic agents, mainly due to their magnetic properties. Here, we designed superparamagnetic iron oxide nanoparticles (SPIONs) to induce apoptosis of human fibroblasts. SPIONs were synthesized via co-precipitation method and coated with sodium citrate (SPION_Cit). We assessed the intracellular uptake of SPIONs by human fibroblast cells, as well as their cytotoxicity and ability to induce thermal effects under the magnetic field. The efficiency and time of nanoparticle internalization were assessed by Prussian Blue staining, flow cytometry and transmission electron microscopy. SPIONs_Cit were detected in the cytoplasm of human fibroblasts 15 min after in vitro exposure, entering into cells mainly via endocytosis. Analyses through Cell Titer Blue assay, AnnexinV-fluorescein isothiocyanate (FITC) and propidium iodide (PI) cellular staining demonstrated that concentrations below 8 x 10(-2) mg/mL of SPIONs_Cit did not alter cell viability of human fibroblast. Furthermore, it was also demonstrated that SPIONs_Cit associated with alternating current magnetic field were able to induce hyperthermia and human fibroblast cell death in vitro, mainly through apoptosis (83.5%), activating caspase 8 (extrinsic apoptotic via) after a short exposure period. Collectively these findings suggest that our nanoplatform is biocompatible and can be used for therapeutic purposes in human biological systems, such as inducing apoptosis of CAFs.

Abstract Hancornia speciosa is a medicinal species traditionally used in Brazilian folk medicine to treat a variety of conditions. Compounds isolated from the leaves, bark, and trunk of this plant have shown therapeutic properties, but only recently have the fruits of H. speciosa been explored for potential pharmacological applications. The present study investigated the effects of an ethanolic extract from the fruits, fractions, and compounds thereof in bone resorbing cells. Primary osteoclast cultures from bone marrow cells and osteoclasts derived from a monocyte/macrophage cell line, RAW 264.7, were incubated with different concentrations of the ethanolic extract, ethyl acetate fraction, water fraction, quinic acid, and L-(+)-bornesitol. In RAW 264.7 cell cultures, quinic acid significantly reduced osteoclast formation. In bone marrow cell-derived osteoclasts, the ethyl acetate fraction induced a decrease in the number of osteoclasts, promoting a remarkable reduction in the mean area of those cells and in their resorption activity. The compounds quinic acid and bornesitol also affected bone marrow cell-derived osteoclasts. In both cell cultures, the substances tested did not affect cell viability/proliferation. In conclusion, components extracted from H. speciosa fruit affected the cells responsible for bone resorption, making them promising tools for interference in osteoclastogenesis.

In vitro eye toxicity assessment using reconstructed corneal epithelial models has emerged highlighting its applicability domain for Classification and Labeling of products and chemicals. However, due to bureaucratic issues, such models are not commercially available in Brazil and Latin America. In this work, we developed, characterized and evaluated the applicability of a new corneal epithelial biomimetic model using a cell lineage for in vitro eye toxicity assessment. The reconstructed tissue was obtained through the cultivation of HaCaT cells in an air-liquid interface, which presented morphology and biomarkers expression such as cytokeratin, CD44, and Ki-67 similar to human tissue. Furthermore, tissue viability was evaluated after exposure of the epithelial model to isolated chemicals from different Globally Harmonized System (GHS) eye irritation categories, and it has been demonstrated to be a suitable endpoint for classification of test materials, allowing discrimination between irritant and non-irritant chemicals. Furthermore, the model showed suitability for testing "real-life mixtures", once it identified irritant products between the analyzed eyebrow henna samples commercially labeled as non-irritants. This reproducible and low-cost epithelial corneal model presents features very important for Brazil and South America for R&D&I with no unnecessary animal experimentation.

Several pretreatment strategies focus on the removal of a significant part of lignin from plant cell walls, as it is considered the main barrier to the process of deconstructing biomass to simple sugars by hydrolytic enzymes. The ability to chemically differentiate and spatially locate lignins across cell walls provides an important contribution to the effort to improve these processes. Here, we present a novel approach using synchrotron phasecontrast tomography to probe the physicochemical features of plant cell walls. In addition to the 3D cellular architecture, the distribution of dense packed lignin–carbohydrate complexes (or, simply dense lignin) over larger regions and within cell walls has been successfully provided. We examined in particular the effect of the sequential H2SO4 and NaOH pretreatment on sugacane bagasse. Our results revealed that aggregates of dense lignin form elongated 3D structures in cell corners (CC) following the orientation of the sclerenchyma fibers; a remarkable result in the light of the conventional perception that lignin particles are discrete and roughly spherical. After the acid pretreatment, a considerable fraction of the dense lignin primarily located in CCs was removed; and it was further dissolved with the subsequent alkali treatment. Unexpectedly, the two-step pretreatment did not contribute to the cellulose accessibility in terms of available surface area and porosity. This study provides new insights into the underlying mechanisms of biomass deconstruction by pretreatments; and the approach established here can be extended to other systems relevant to the bioenergy and biotechnology arenas.

Antimicrobial peptides present a broad spectrum of therapeutic applications, including their use as anticancer peptides. These peptides have as target microbial, normal, and cancerous cells. The oncological properties of these peptides may occur by membranolytic mechanisms or non-membranolytics. In this work, we demonstrate for the first time the cytotoxic effects of the cationic alpha-helical antimicrobial peptide LyeTx I-b on glioblastoma lineage U87-MG. The anticancer property of this peptide was associated with a membranolytic mechanism. Loss of membrane integrity occurred after incubation with the peptide for 15min, as shown by trypan blue uptake, reduction of calcein-AM conversion, and LDH release. Morphological studies using scanning electron microscopy demonstrated disruption of the plasma membrane from cells treated with LyeTx I-b, including the formation of holes or pores. Transmission electron microscopy analyses showed swollen nuclei with mild DNA condensation, cell volume increase with an electron-lucent cytoplasm and organelle vacuolization, but without the rupture of nuclear or plasmatic membranes. Morphometric analyses revealed a high percentage of cells in necroptosis stages, followed by necrosis and apoptosis at lower levels. Necrostatin-1, a known inhibitor of necroptosis, partially protected the cells from the toxicity of the peptide in a concentration-dependent manner. Imaging flow cytometry confirmed that 59% of the cells underwent necroptosis after 3-h incubation with the peptide. It is noteworthy that LyeTx I-b showed only mild cytotoxicity against normal fibroblasts of human and monkey cell lines and low hemolytic activity in human erythrocytes. All data together point out the anticancer potential of this peptide.

BACKGROUNDBenign neoplasms exhibit most of the cellular phenomena considered hallmarks of cancer, except the capacity to metastasize. Thus, the elucidation of the mechanisms associated with the progression of benign neoplasms may complement and clarify the mechanisms involved in carcinogenesis. Benign odontogenic tumours often result in facial deformities and morbidities, and have complex pathogenesis, mainly due to the diversity of interactions between the odontogenic epithelium and the ectomesenchyme. Primary cell culture of such tumours is not only difficult to be established and maintained, but also tumour cells lose characteristic cellular morphology. Considering gene expression, growth, migration, proliferation and cellular morphology are controlled by cell-cell interactions and cell-extracellular matrix interactions, cell culture in 3D substrates has gained space as a way to overcome some of the limitations of traditional monolayer cell culture systems.METHODSIn this study, fragments obtained from mesenchymal odontogenic tumours were cultured in type I collagen scaffolds. Invasion tests were performed in these models, as well as phenotypic characterization of the cultured tumours.RESULTSThe results obtained for the odontogenic myxoma and the cemento-ossifying fibroma demonstrate a good reproduction of the growth pattern of these tumours under ex vivo conditions. Microscopic evaluation showed maintenance of cell viability in the explants for more than 30 days, without the presence of necrosis.CONCLUSIONThis is the first study involving long-term 3D primary cultures of benign odontogenic tumours, which is expected to support complex approaches to cell and molecular biology, and to serve as an experimental model for testing molecular therapies.

AIMS:This study characterized a three-dimensional (3D) biocomposite scaffolds produced using type I collagen, mineral trioxide aggregate (MTA) and multi-walled carbon nanotubes (MWCNT) to be used in bone tissue regeneration.MAIN METHODS:The scaffolds were analyzed via scanning (SEM) and transmission (TEM) electron microscopy, as well as the viability and migration of osteoblasts and mineralization of the scaffolds.KEY FINDINGS:SEM and TEM analyses showed that MTA and MWCNT were distributed as both large agglomerates entrapped within the collagen network and as smaller accumulations or individual molecules dispersed throughout the scaffold. Ultrastructural analysis revealed that osteoblastic MC3T3-E1 cells grown in the biocomposite endocytosed MWCNT, which were localized in the cytoplasm and in vesicles. Analysis of cells grown in the 3D scaffolds demonstrated that >95% of the cells remained viable in all tested combinations and concentrations of the biocomposite. MC3T3-E1 osteoblasts migrated into scaffolds formed with concentrations of type I collagen between 1.75 and 3.0mg/mL. Cells displayed increased migration into scaffolds formed with collagen and a range of low to high concentrations of MTA. In contrast, the presence of MWCNT in the biocomposite had a slight negative effect on migration. Collagen gels containing specific concentrations of MTA, or MWCNT, or combinations of MTA/MWCNT, caused an increase in mineralization of scaffolds.SIGNIFICANCE:Scaffolds composed of defined concentrations of type I collagen, MTA and MWCNT are biocompatible, promote migration and mineralization of osteoblasts, and hence may be useful as bone tissue mimetics.

OBJECTIVESThis study aimed to evaluate types I, III and IV collagen in healthy gingival tissue and to compare them to gingival tissues suffering from chronic gingivitis and chronic periodontitis.MATERIALS AND METHODSThirty-two man patients were selected. The patients belonged to three diagnostic categories: healthy gingiva (HG), chronic gingivitis (CG) and chronic periodontitis (CP), based on clinical and radiographical criteria. Gingival tissue samples were obtained from patients who underwent periodontal surgery procedures. Hematoxylin and Eosin (HE), Picrosirius red, indirect immunofluorescence by confocal microscopy and quantitative analyses were performed to identify the presence and location of types I, III and IV collagen. Statistical significance was verified using the Kruskal-Wallis test.RESULTSSamples from HG group showed thick collagen fibers arranged in a parallel pattern. Samples from CG group showed dilated blood vessels; collagen fibers and inflammatory cells were found dispersed throughout the tissue. Samples from CP group showed the extracellular matrix severely damaged, disorganized collagen fibers and large amount of inflammatory cells. The HG group showed an apparent higher expression of type I collagen, when compared to tissues with CG and CP, however no statistical differences were detected (p=0.064). The types III and IV collagen fibers showed no difference in expression in tissues with gingivitis and periodontitis.CONCLUSIONSFollowing the periodontal disease there was a morphological destruction of the extracellular matrix with lower expression of collagen, which led to a change in tissue architecture that might compromise its functional capacity. There were differences in type I collagen expression among healthy, chronic gingivitis and chronic periodontitis tissue samples.

Repulsive guidance molecules (RGMs) compose a family of glycosylphosphatidylinositol (GPI)-anchored axon guidance molecules and perform several functions during neural development. New evidence has suggested possible new roles for these axon guidance molecules during skeletal muscle development, which has not been investigated thus far. In the present study, we show that RGMa, RGMb and RGMc are all induced during skeletal muscle differentiation in vitro. Immunolocalization performed on adult skeletal muscle cells revealed that RGMa, RGMb and RGMc are sarcolemmal proteins. Additionally, RGMa was found to be a sarcoplasmic protein with a surprisingly striated pattern. RGMa colocalization with known sarcoplasmic proteins suggested that this axon guidance molecule is a skeletal muscle sarcoplasmic protein. Western blot analysis revealed two RGMa fragments of 60 and 33 kDa, respectively, in adult skeletal muscle samples. RGMa phenotypes in skeletal muscle cells (C2C12 and primary myoblasts) were also investigated. RGMa overexpression produced hypertrophic cells, whereas RGMa knockdown resulted in the opposite phenotype. RGMa knockdown also blocked myotube formation in both skeletal muscle cell types. Our results are the first to show an axon guidance molecule as a skeletal muscle sarcoplasmic protein and to include RGMa in a system that regulates skeletal muscle cell size and differentiation.

In this study we investigated the effects of genetic deletion of the Angiotensin-(1-7) receptor Mas or the Angiotensin II receptor AT2 on the expression of specific extracellular matrix (ECM) proteins in atria, right ventricles and atrioventricular (AV) valves of neonatal and adult mice. Quantification of collagen types I, III and VI and fibronectin was performed using immunofluorescence-labeling and confocal microscopy. Picrosirius red staining was used for the histological assessment of the overall collagen distribution pattern. ECM proteins, metalloproteinases (MMP), ERK1/2 and p38 levels were quantified by western blot analysis. Gelatin zymography was used to evaluate the activity of MMP-2 and MMP-9. We observed that the relative levels of collagen types I and III and fibronectin are significantly higher in both the right ventricle and AV valves of neonatal Mas−/− mouse hearts (e.g., collagen type I: 85.28 ± 6.66 vs 43.50 ± 4.41 arbitrary units in the right ventricles of Mas+/+ mice). Conversely, the level of collagen type VI was lower in the right ventricle and AV valves of Mas−/− mice. Adult Mas−/− mouse hearts presented similar patterns as observed in neonates. No significant differences in ECM protein level were detected in atria. Likewise, no changes in ECM levels were observed in AT2 knockout mouse hearts. Although deletion of Mas induced a significant reduction in the level of the active form of MMP-2 in neonate hearts and a reduction of both MMP-2 and MMP-9 in adult Mas−/− mice, no significant differences were observed in MMP enzymatic activities when compared to controls. The levels of the active, phosphorylated forms of ERK1/2 and p38 were higher in hearts of both neonatal and adult Mas−/− mice. These observations suggest that Mas is involved in the selective expression of specific ECM proteins within both the ventricular myocardium and AV valves. The changes in the ECM profile may alter the connective tissue framework and contribute to the decreased cardiac performance observed in Mas−/− mice.

In recent years, stem cell research has grown exponentially owing to the recognition that stem cell-based therapies have the potential to improve the life of patients with conditions that range from Alzheimer's disease to cardiac ischemia and regenerative medicine, like bone or tooth loss. Based on their ability to rescue and/or repair injured tissue and partially restore organ function, multiple types of stem/progenitor cells have been speculated. Growing evidence demonstrates that stem cells are primarily found in niches and that certain tissues contain more stem cells than others. Among these tissues, the dental tissues are considered a rich source of mesenchymal stem cells that are suitable for tissue engineering applications. It is known that these stem cells have the potential to differentiate into several cell types, including odontoblasts, neural progenitors, osteoblasts, chondrocytes, and adipocytes. In dentistry, stem cell biology and tissue engineering are of great interest since may provide an innovative for generation of clinical material and/or tissue regeneration. Mesenchymal stem cells were demonstrated in dental tissues, including dental pulp, periodontal ligament, dental papilla, and dental follicle. These stem cells can be isolated and grown under defined tissue culture conditions, and are potential cells for use in tissue engineering, including, dental tissue, nerves and bone regeneration. More recently, another source of stem cell has been successfully generated from human somatic cells into a pluripotent stage, the induced pluripotent stem cells (iPS cells), allowing creation of patient- and disease-specific stem cells. Collectively, the multipotency, high proliferation rates, and accessibility make the dental stem cell an attractive source of mesenchymal stem cells for tissue regeneration. This review describes new findings in the field of dental stem cell research and on their potential use in the tissue regeneration.

Angiotensin (Ang) II is involved in inflammatory and fibrotic mechanisms of cardiovascular and renal diseases. Ang-(1-7) counterbalances most of the Ang II pathophysiological effects. However, a protective role for Ang-(1-7) in kidney fibrosis remains speculative. To evaluate the role of Ang-(1-7) receptor Mas on pathophysiological mechanisms of kidney fibrosis we used a distinct genetic background of Mas-knockout mice (FVB/N MasKO). Urine and plasma samples were collected for measuring renal function parameters. Kidneys were harvested for histology, confocal immunofluorescence of matrix proteins, RT-PCR of AT1 receptor and TGF-beta and TUNEL apoptosis. Compared with wild-type controls, MasKO mice have reduced 24h-urine volume (0.75±0.15 vs. 1.51±0.33mL p<0.05) and sodium fractional excretion (1.09±0.21 vs. 2.16±0.45% p<0.05), without changes in osmolal and free-water clearances. The 1.8-fold higher creatinine clearance (7.11±1.25 vs. 3.92±0.48µL.min.g -1 p<0.05) and the 2.9-fold increase in albuminuria (3.42±0.56 vs. 1.17±0.27µg.g -1 p<0.05) detected in MasKO mice suggest glomerular hyperfiltration. Histology showed variable degrees of mesagial cells proliferation and segmental glomerulosclerosis, with an increased index of glomerular lesion in MasKO (0.56±0.08 vs. 0.25±0.10 p<0.05). These findings were associated with increased glomerular content of collagens I and IV, fibronectin, Ang II and upregulation of mRNA for AT1 receptor and TGF-beta. TUNEL staining revealed a 2-fold augmentation in fluorescence of apoptotic nuclei from glomerular and tubular cells in MasKO. Our results suggest that Mas receptor may exert protective role on renal fibrosis and apoptosis, possibly counterbalancing Ang II and TGF-beta effects in the kidney.