Inhibition of Rho kinase (ROCK) impairs cytoskeletal contractility in human Müller glial cells without effects on cell viability, migration, and extracellular matrix production.

The epiretinal membrane is a fibrocontractile tissue that forms on the inner surface of the retina, causing visual impairment ranging from mild to severe, and even retinal detachment. Müller glial cells actively participate in the formation of this membrane. Current research is constantly seeking for new therapeutic approaches that aim to prevent or treat cellular dysfunctions involved in the progression of this common fibrosis condition. The Rho GTPases signaling pathway regulates several processes associated with the epiretinal membrane, such as cell proliferation, migration, and contraction. Rho kinase (ROCK), an effector of the RhoA GTPase, is an interesting potential therapeutic target. This study aimed to evaluate the effects of a ROCK inhibitor (Y27632) on human Müller cells viability, growth, cytoskeletal organization, expression of extracellular matrix components, myofibroblast differentiation, migration, and contractility. Müller cells of the MIO-M1 lineage were cultured and treated for different periods with the inhibitor. Viability was evaluated by MTT assay and trypan blue exclusion method, and growth was evaluated by growth curve and BrdU incorporation assay. The actin cytoskeleton was stained with fluorescent phalloidin, intermediate filaments and microtubules were analyzed with immunofluorescence for vimentin and α-tubulin. Gene and protein expression of collagens I and V, laminin and fibronectin were evaluated by rt-PCR and immunofluorescence. Chemotactic and spontaneous cell migration were studied by transwell assay and time-lapse observation of live cells, respectively. Cell contractility was assessed by collagen gel contraction assay. The results showed that ROCK inhibition by Y27632 did not affect cell viability, but decreased cell growth and proliferation after 72 h. There was a change in cell morphology and organization of F-actin, with a reduction in the cell body, disappearance of stress fibers and formation of long, branched cell extensions. Microtubules and vimentin filaments were also affected, possibly because of F-actin alterations. The inhibitor also reduced gene expression and immunoreactivity of smooth muscle α-actin, a marker of myofibroblasts. The expression of extracellular matrix components was not affected by the inhibitor. Chemotactic cell migration showed no significant changes, while cell contractility was substantially reduced. No spontaneous migration of MIO-M1 cells was observed. In conclusion, pharmacological inhibition of ROCK in Müller cells could be a potentially promising approach to treat epiretinal membranes by preventing cell proliferation, contractility and transdifferentiation, without affecting cell viability.

Age-related increase of let-7 family microRNA in rat retina and vitreous.

Vitreous alterations occur from early stages and continue through the normal aging, with gradual lamellae formation and the appearance of liquefied spaces, which eventually leads to complications, such as retinal tear, retinal detachment, and intravitreal hemorrhage. The aim of the present study was to investigate the expression of let-7 miRNA family in the vitreous and retina in newborn (1-3- day-old), young adult (2-month-old), and aging (12-month-old) rats, as well as their role as regulators of vitreous components. MicroRNAs are small, non-coding RNAs that post-transcriptionally regulate gene expression. Our results showed detection of all investigated let-7 isoforms (let-7a, let-7b, let-7c, let-7d, let-7e, let-7f and let-7i) in the retina and vitreous. Although most let-7 members were significantly upregulated in the vitreous during development, only let-7b, let-7c, and let-7e followed this same expression pattern in the retina. Let-7b and -7c increased in aging vitreous as well, and were expressed in vitro by Müller glial cells and their extracellular vesicles. Moreover, let-7 targeted hyaluronan synthase 2 (Has2) mRNA, a synthesizing enzyme of hyaluronan. These observations indicate that let-7 function is important during retina and vitreous development, and that isoforms of let-7 increased with aging, potentially modulating hyaluronan content.

Topical cream containing nanoparticles with vitamin E to prevent radiodermatitis in women with breast cancer: a clinical trial protocol.

OBJECTIVE: Little is known about the efficacy of products aiming to prevent radiodermatitis, which affects between 90-95% of women with breast cancer. The use of antioxidants is promising, however, there is a lack of evidenceon their effectiveness. Here, the authors present a clinical trial protocol to evaluate the effects of applying a cream containing nanoparticles with vitamin E to prevent radiodermatitis in patients with breast cancer. METHOD: The protocol recommends that 108 women with breast cancer, receiving radiotherapy, are included in this triple-blinded, randomized, controlled study at an oncology hospital. Patients will be divided in three groups of 36 individuals each: group A will receive a cream with lipid nanoparticles and vitamin E, group B will receive a cream without nanoparticles nor vitamin E, and group C will receive a cream with nanoparticles without vitamin E. The primary endpoints will evaluate the incidence, degree, and time of onset of radiodermatitis. The secondary endpoints will focus on the quality of life, symptoms, and local temperature. Patients will be assessed three times a week, from the start of their radiotherapy treatment to two weeks after the last session. This protocol was approved by the research ethics committee of the institutions involved and registered on an international trials database.

Topical cream containing nanoparticles with vitamin E to prevent radiodermatitis in women with breast cancer: a clinical trial protocol.

OBJECTIVE: Little is known about the efficacy of products aiming to prevent radiodermatitis, which affects between 90-95% of women with breast cancer. The use of antioxidants is promising, however, there is a lack of evidenceon their effectiveness. Here, the authors present a clinical trial protocol to evaluate the effects of applying a cream containing nanoparticles with vitamin E to prevent radiodermatitis in patients with breast cancer. METHOD: The protocol recommends that 108 women with breast cancer, receiving radiotherapy, are included in this triple-blinded, randomized, controlled study at an oncology hospital. Patients will be divided in three groups of 36 individuals each: group A will receive a cream with lipid nanoparticles and vitamin E, group B will receive a cream without nanoparticles nor vitamin E, and group C will receive a cream with nanoparticles without vitamin E. The primary endpoints will evaluate the incidence, degree, and time of onset of radiodermatitis. The secondary endpoints will focus on the quality of life, symptoms, and local temperature. Patients will be assessed three times a week, from the start of their radiotherapy treatment to two weeks after the last session. This protocol was approved by the research ethics committee of the institutions involved and registered on an international trials database.

MiRNA-146b-5p upregulates migration and invasion of different Papillary Thyroid Carcinoma cells.

BACKGROUND: Tumor invasiveness is directly related to the ability of tumor cells to migrate and invade surrounding tissues, usually degrading extracellular matrix. Despite significant progress in the knowledge about migration and invasion, there is much more to elucidate about their regulatory mechanisms, especially in cancer cells. MicroRNAs (miRs) were recently described as important regulators of migration. Differential expression of miRs in cancer is frequently associated with progression, invasion and metastasis. In papillary thyroid carcinoma (PTC), miR-146b-5p is highly expressed and positively correlated to the degree of malignancy. METHODS: This study aimed to investigate the role of miR-146b-5p on the migratory and invasive behaviors of thyroid cells, using a non tumor rat thyroid follicular cell line (PCCl3) transfected with the miR-146b-5p genomic region, and two PTC cell lines (TPC-1 and BCPAP, bearing distinct oncogenic backgrounds), which express high levels of miR-146b-5p, after miR-146b inhibition by antagomiR and miR-146b overexpression by mimics-miR. Migration and invasion were studied by time-lapse and transwell assays (with and without Matrigel®). Gelatin degradation assays were also employed, as well as F-actin staining. RESULTS: Migration and invasion of PCCl3 were increased 2-3x after miR-146b-5p overexpression (10X) and large lamellipodia were evident in those cells. After miR-146b-5p inhibition, TPC-1 and BCPAP migration and invasion were significantly reduced, with cells showing several simultaneous processes and low polarity. Gelatin degradation was inhibited in TPC-1 cells after inhibition of miR-146b-5p, but was unaffected in BCPAP cells, which did not degrade gelatin. The inhibition of miR-146b-5p in PCCl3 also inhibited migration and invasion, and additional (exogenous) overexpression of this miR in TPC-1 and BCPAP cells increased migration and invasion, without effects on cell morphology or gelatin degradation. The overexpression of SMAD4 in BCPAP cells, a validated target of miR-146b-5p and key protein in the TGF-ß signaling pathway, inhibited migration similarly to the effects observed with the antagomiR 146b-5p. CONCLUSIONS: miR-146b-5p positively regulates migration and invasion of thyroid normal and tumor follicular cells (independently from their original mutation, either BRAF or RET/PTC), through a mechanism that involves the actin cytoskeleton but not an increased capacity of matrix degradation.

Oral administration of antioxidants improves skin wound healing in diabetic mice.

Oxidative stress aggravates several long-term complications in diabetes mellitus. We evaluated the effectiveness of the oral administration of antioxidants (vitamins E and C, 40 and 100 mg/kg b.w., respectively) on skin wound healing acceleration in alloxan-induced diabetic mice. Mice were wounded 30 days after the induction of diabetes. Antioxidants were effective in preventing oxidative stress, as assessed by TBARS. The enzymes catalase, glutathione reductase, glutathione peroxidase, and superoxide dismutase were increased in diabetics on the 3rd day post-wounding; catalase and glutathione peroxidase remained still augmented in diabetics after 14th day postwounding, and the treatment with vitamins restored their activities to control. After 3 days, diabetic mice showed lower infiltration of inflammatory cells (including CD11b+ and Ly6G+ cells) and reduced levels of KC, TNF-α, IL-1ß, and IL-12 p40 when compared with control mice. The treatment restored cytokine levels. After 14 days, diabetic mice showed late wound closure, persistent inflammation and delayed reepithelialization, accompanied by an increase in MIG+ /CD206- macrophages whereas CD206+ /MIG- macrophages were decreased. Cytokines IL-12p40, TNF-α, IL-1ß, and KC were increased and normal levels were restored after treatment with antioxidants. These results suggest that oxidative stress plays a major role in diabetic wound healing impairment and the oral administration of antioxidants improves healing by modulating inflammation and the antioxidant system with no effect on glycemia.

Clinical protocol for the topical use of a cream with nanoparticles and vitamin E to prevent radiodermatitis in patients with breast cancer]. / Aplicación tópica de crema con nanopartículas con vitamina E para prevenir radiodermatitis en cáncer de mama: protocolo de ensayo clínico.

Objetivo: Poco se conoce sobre la eficacia de productos para la prevención de radiodermatitis, que afecta al 90­95% de las mujeres con cáncer de mama. El uso de antioxidantes es promisorio, sin embargo, poco estudiado. Los autores desarrollaron un protocolo de ensayo clínico para evaluar el efecto potencial de la aplicación de crema con nanopartículas con vitamina E para prevenir radiodermatitis aguda en mujeres con cáncer de mama. Método: El protocolo sugiere que 108 mujeres adultas con cáncer de mama, que estén recibiendo radioterapia, sean incluidas en este ensayo clínico, controlado, aleatorizado y triple ciego, en un hospital oncológico. Se prevé la distribución de pacientes en tres grupos de 36 personas: el grupo A recibirá una crema con nanopartículas lipídicas con vitamina E, el grupo B obtendrá una crema sin nanopartículas ni vitamina E, y el grupo C usará una crema con nanopartículas sin vitamina E. Los resultados primarios evaluarán la incidencia, el grado y el tiempo de surgimiento de la radiodermatitis. Los resultados secundarios se centrarán en la calidad de vida, los síntomas y la temperatura local. Las pacientes serán evaluadas tres veces por semana, desde el inicio de la radioterapia hasta dos semanas después de la última sesión. El presente proyecto fue aprobado por el comité de ética en investigación de las instituciones involucradas.Objective: Little is known about the efficacy of products that aim to prevent radiodermatitis, which affects between 90­95% of women with breast cancer. The use of antioxidants is promising, however, there is a lack of evidence on their effectiveness. Here, the authors present a clinical trial protocol to evaluate the potential effects of applying a nanoparticle cream with vitamin E to prevent radiodermatitis in patients with breast cancer. Method: The protocol recommends that 108 women with breast cancer, who are receiving radiotherapy, be included in a triple-blinded, randomised, controlled study in an oncology hospital. Patients will be divided in three groups of 36 people each: group A will receive a cream with lipid nanoparticles and vitamin E, group B will obtain a cream without nanoparticles or vitamin E, and group C will receive a cream with nanoparticles without vitamin E. The primary endpoints will evaluate the incidence, degree and time of onset of radiodermatitis. The secondary endpoints will focus on quality of life, symptoms and local temperature. Patients will be assessed three times a week, from the start of their radiotherapy treatment to two weeks after the last session. This protocol was approved by the research ethics committee of the institutions involved.

Topical application of a cream containing nanoparticles with vitamin E for radiodermatitis prevention in women with breast cancer: A randomized, triple-blind, controlled pilot trial.

PURPOSE: Most topical agents for radiodermatitis prevention are not based on its pathophysiology, mainly caused by the indirect effects of radiation from reactive oxygen species release. Therefore, this study aimed to evaluate the effect of vitamin E-containing nanoparticle cream as an antioxidant for radiodermatitis prevention. METHOD: A randomized, triple-blind, parallel pilot study conducted in an Oncology Hospital including 40 adult women with breast cancer, and healthy skin, submitted to radiotherapy, divided into three groups: Intervention (12; 30%) receiving cream with nanoparticles containing vitamin E; Control 1 (14; 35%) cream without nanoparticles or vitamin E; Control 2 (14; 35%) cream with nanoparticles without vitamin E. Incidence, grade and time to onset of radiodermatitis were primary outcomes; health-related quality of life, reported symptoms, and breast temperature were secondary outcomes. RESULTS: All patients were followed until the end of the study. All had radiodermatitis. There were no significant differences between the study groups regarding radiodermatitis grade, health-related quality of life, and breast temperatures. A protective effect of vitamin E-containing nanoparticle cream was identified regarding the onset time of radiodermatitis in patients who did not receive a boosted radiation dose (p = .03) and the occurrence of mild inframammary erythema (p = .04). Itching was reported by 90% of the women. The definitive calculated sample is 108 volunteers. There were no identified side effects. CONCLUSIONS: A potential protective effect of a cream containing vitamin E nanoparticles was observed. This pilot study presents initial evidence about the role of a nanoencapsulated antioxidant in preventing radiodermatitis. TRIAL REGISTRATION: No. RBR-784F3Y; UTN-U1111-1201-5923.

Rho signaling pathway and apical constriction in the early lens placode.

Epithelial invagination in many model systems is driven by apical cell constriction, mediated by actin and myosin II contraction regulated by GTPase activity. Here we investigate apical constriction during chick lens placode invagination. Inhibition of actin polymerization and myosin II activity by cytochalasin D or blebbistatin prevents lens invagination. To further verify if lens placode invaginate through apical constriction, we analyzed the role of Rho-ROCK pathway. Rho GTPases expression at the apical portion of the lens placode occurs with the same dynamics as that of the cytoskeleton. Overexpression of the pan-Rho inhibitor C3 exotoxin abolished invagination and had a strong effect on apical myosin II enrichment and a mild effect on apical actin localization. In contrast, pharmacological inhibition of ROCK activity interfered significantly with apical enrichment of both actin and myosin. These results suggest that apical constriction in lens invagination involves ROCK but apical concentration of actin and myosin are regulated through different pathways upstream of ROCK. genesis 49:368-379, 2011.

Crotoxin Inhibits Endothelial Cell Functions in Two- and Three-dimensional Tumor Microenvironment.

Antitumor property of Crotoxin (CTX), the major toxin from Crotalus durissus terrificus snake venom, has been demonstrated in experimental animal models and clinical trials. However, the direct action of this toxin on the significant events involved in neovascularization, which are essential for tumor growth and survival, has not been confirmed. This study investigated the effects of CTX on the key parameters of neovascularization in two- and three-dimensional culture models. Murine endothelial cell lines derived from thymus hemangioma (t.End.1) were treated at different concentrations of CTX (6.25-200 nM). Endothelial cell proliferation, cell adhesion, and actin cytoskeletal dynamics on laminin (10 µg/ml), type I collagen (10 µg/ml), and fibronectin (3 µg/ml) were evaluated along with the endothelial cell migration and formation of capillary-like tubes in 3D Matrigel. CTX concentration of 50 nM inhibited tube formation on 3D Matrigel and impaired cell adhesion, proliferation, and migration under both culture medium and tumor-conditioned medium. These actions were not accountable for the loss of cell viability. Inhibition of cell adhesion to different extracellular matrix components was related to the reduction of αv and α2 integrin distribution and cytoskeletal actin polymerization (F-actin), accompanied by inhibition of focal adhesion kinase (FAK), Rac1 (GTPase) signaling proteins, and actin-related protein 2/3 (Arp 2/3) complex. This study proved that CTX inhibits the major events involved in angiogenesis, particularly against tumor stimuli, highlighting the importance of the anti-angiogenic action of CTX in inhibition of tumor progression.

RECK-mediated inhibition of glioma migration and invasion.

RECK is an anti-tumoral gene whose activity has been associated with its inhibitory effects regulating MMP-2, MMP-9, and MT1-MMP. RECK level decreases as gliobastoma progresses, varying from less invasive grade II gliomas to very invasive human glioblastoma multiforme (GBM). Since RECK expression and glioma invasiveness show an inverse correlation, the aim of the present study is to investigate whether RECK expression would inhibit glioma invasive behavior. We conducted this study to explore forced RECK expression in the highly invasive T98G human GBM cell line. Expression levels as well as protein levels of RECK, MMP-2, MMP-9, and MT1-MMP were assessed by qPCR and immunoblotting in T98G/RECK+ cells. The invasion and migration capacity of RECK+ cells was inhibited in transwell and wound assays. Dramatic cytoskeleton modifications were observed in the T98G/RECK+ cells, when compared to control cells, such as the abundance of stress fibers (contractile actin-myosin II bundles) and alteration of lamellipodia. T98G/RECK+ cells also displayed phosphorylated focal adhesion kinase (P-FAK) in mature focal adhesions associated with stress fibers; whereas P-FAK in control cells was mostly associated with immature focal complexes. Interestingly, the RECK protein was predominantly localized at the leading edge of migrating cells, associated with membrane ruffles. Unexpectedly, introduced expression of RECK effectively inhibited the invasive process through rearrangement of actin filaments, promoting a decrease in migratory ability. This work has associated RECK tumor-suppressing activity with the inhibition of motility and invasion in this GBM model, which are two glioma characteristics responsible for the inefficiency of current available treatments.

GTPases RhoA and Rac1 are important for amelogenin and DSPP expression during differentiation of ameloblasts and odontoblasts.

Morphogenesis and cytodifferentiation are distinct processes in tooth development. Cell proliferation predominates in morphogenesis; differentiation involves changes in form and gene expression. The cytoskeleton is essential for both processes, being regulated by Rho GTPases. The aim of this study was to verify the expression, distribution, and role of Rho GTPases in ameloblasts and odontoblasts during tooth development in correlation with actin and tubulin arrangements and amelogenin and dentin sialophosphoprotein (DSPP) expression. RhoA, Rac1, and Cdc42 were strongly expressed during morphogenesis; during cytodifferentiation, RhoA was present in ameloblasts and odontoblasts, Rac1 and its effector Pak3 were observed in ameloblasts; and Cdc42 was present in all cells of the tooth germ and mesenchyme. The expression of RhoA mRNA and its effectors RockI and RockII, Rac1 and Pak3, as analyzed by real-time polymerase chain reaction, increased after ameloblast and odontoblast differentiation, according to the mRNA expression of amelogenin and DSPP. The inhibition of all Rho GTPases by Clostridium difficile toxin A completely abolished amelogenin and DSPP expression in tooth germs cultured in anterior eye chamber, whereas the specific inhibition of the Rocks showed only a partial effect. Thus, both GTPases are important during tooth morphogenesis. During cytodifferentiation, Rho proteins are essential for the complete differentiation of ameloblasts and odontoblasts by regulating the expression of amelogenin and DSPP. RhoA and its effector RockI contribute to this role. A specific function for Rac1 in ameloblasts remains to be elucidated; its punctate distribution indicates its possible role in exocytosis/endocytosis.

Effect of thyroid hormones on rat exocrine pancreas morphology and function.

AIM: The influence of thyroid hormones on exocrine pancreas function is poorly understood, and limited to the postnatal development period. Here, we evaluated the effects of hypo- and hyperthyroidism on the morphology and enzyme content of this tissue. MAIN METHODS: To induce hypothyroidism male Wistar rats were subjected to a thyroidectomy (Tx) or sham operated (SO). After 40 days, some of the Tx and SO rats were treated with T3 for 7 days. Following euthanization, the pancreas was removed and evaluated for morphology, as well as amylase, lipase and trypsin content, using histological and immunoreactive techniques analyses, respectively. Serum amylase levels were also evaluated. KEY FINDINGS: The pancreatic acinar cells of Tx rats were smaller, exhibited reduced Haematoxyllin stained areas, and contained lower amylase and lipase levels, indicative of low cell activity. Tx rats also presented higher collagen levels, and high trypsin content in pancreatic extracts. Interestingly, T3 administration reversed the observed acinar cell alterations and restored pancreatic enzyme content, by augmenting amylase and lipase and attenuating trypsin levels, but failed to change collagen content. Increased levels of lipase and decreased trypsin were also observed in T3-treated SO rats. SIGNIFICANCE: Thyroid hormones play an important role in acinar cell morphology and function. In the hypothyroid state there is a decrease in pancreatic enzyme levels that is restored with T3 treatment. In addition to participating in insulin sensitivity and glycemic control, THs also modulate enzyme expression and activity in the exocrine pancreas, consequently, delivering metabolic substrates to specific organs and tissues.

Tributyrin Attenuates Metabolic and Inflammatory Changes Associated with Obesity through a GPR109A-Dependent Mechanism.

Obesity is linked with altered microbial short-chain fatty acids (SCFAs), which are a signature of gut dysbiosis and inflammation. In the present study, we investigated whether tributyrin, a prodrug of the SCFA butyrate, could improve metabolic and inflammatory profiles in diet-induced obese mice. Mice fed a high-fat diet for eight weeks were treated with tributyrin or placebo for another six weeks. We show that obese mice treated with tributyrin had lower body weight gain and an improved insulin responsiveness and glucose metabolism, partly via reduced hepatic triglycerides content. Additionally, tributyrin induced an anti-inflammatory state in the adipose tissue by reduction of Il-1ß and Tnf-a and increased Il-10, Tregs cells and M2-macrophages. Moreover, improvement in glucose metabolism and reduction of fat inflammatory states associated with tributyrin treatment were dependent on GPR109A activation. Our results indicate that exogenous targeting of SCFA butyrate attenuates metabolic and inflammatory dysfunction, highlighting a potentially novel approach to tackle obesity.

Delayed local inflammatory response induced by Thalassophryne nattereri venom is related to extracellular matrix degradation.

Symptoms evoked by Thalassophryne nattereri fish envenomation include local oedema, severe pain and intense necrosis with strikingly inefficient healing, continuing for several weeks or months. Investigations carried out in our laboratory showed that, in the venom-induced acute inflammation, thrombosis in venules and constrictions in arterioles were highly visible, in contrast to a notable lack of inflammatory cell. Nevertheless, the reason that the venom toxins favour delayed local inflammatory response is poorly defined. In this study, we analysed the movement of leucocytes after T. nattereri venom injection in the intraplantar region of Swiss mice, the production of pro-inflammatory mediators and the venom potential to elicit matrix metalloproteinase production and extracellular matrix degradation. Total absence of mononuclear and neutrophil influx was observed until 14 days, but the venom stimulates pro-inflammatory mediator secretion. Matrix metalloproteinases (MMP)-2 and MMP-9 were detected in greater quantities, accompanied by tissue degradation of collagenous fibre. An influx of mononuclear cells was noted very late and at this time the levels of IL-6, IL-1beta and MMP-2 remained high. Additionally, the action of venom on the cytoskeletal organization was assessed in vitro. Swift F-actin disruption and subsequent loss of focal adhesion was noted. Collectively these findings show that the altered specific interaction cell-matrix during the inflammatory process creates an inadequate environment for infiltration of inflammatory cells.

Late hyaluronidase injection in local anesthesia: Morphofunctional evaluation in rat sciatic nerve block.

INTRODUCTION: Despite the enhancing effects of hyaluronidase (HYAL) over duration of anesthesia, this enzyme could cause adverse effects when injected concomitantly with local anesthetics in dental blocks. OBJECTIVE: This study aimed to assess the tissue alterations caused by a local anesthetic protocol consisting of a late HYAL injection and confirm its functional effectiveness. MATERIALS AND METHODS: The protocol efficacy was proved by evaluating sensory and motor functions in rats. The sciatic nerve was blocked with 2% lidocaine (LID) with epinephrine (n = 25). Thirty minutes later, 75 TRU/ml HYAL was injected into the same site (experimental group, LID/HYAL). One week later, this protocol was repeated in the contralateral hindlimb, injecting only HYAL's vehicle (control group, LID/vehicle [LID/V]). To observe the integrity of the local tissues, histological specimens were obtained 1, 24, 48, and 72 h after treatment with LID/HYAL or LID/V (n = 16 each) and stained with hematoxylin/eosin and picrosirius red. RESULTS: Local inflammation was similar in both groups. The integrity of the nerve fibers was preserved, in spite of some inflammation-associated injuries in the surrounding tissues. The reversible tissue disorganization caused by HYAL, probably facilitated the diffusion of the residual anesthetic to the nerve, resulting in a prolonged anesthetic effect (P < 0.05). CONCLUSIONS: No irreversible morphological alterations are caused by the administration of HYAL prior the end of the LID-induced block. Moreover, this protocol prolongs LID's anesthetic effect.

Guaiacol/ß-cyclodextrin for rapid healing of dry socket: antibacterial activity, cytotoxicity, and bone repair-an animal study.

PURPOSE: Dry socket (DS) is one the most common and symptomatic post-extraction complications; however, no consensus on its treatment has been reached. This study aimed to develop a novel dressing material for DS containing the phenolic agent guaiacol and evaluate its biological properties. METHODS: An inclusion complex of guaiacol and ß-cyclodextrin (Gu/ßcd) was prepared by freeze-drying. Its antibacterial activity over six oral bacteria was analyzed using the microdilution method, and its cytotoxicity in osteoblasts was assessed with the MTT assay. The alveolar healing process induced by Gu/ßcd was evaluated histologically after the treatment of DS in rats. RESULTS: ßcd complexation potentiated Gu's antibacterial effect and reduced its cytotoxicity in osteoblasts. Bone trabeculae were formed in the alveolar apices of rats treated with Gu/ßcd by day 7. On day 14, woven bone occupied the apical and middle thirds of the sockets; on day 21, the entire alveolus was filled by newly formed bone, which was in a more advanced stage of repair than the positive control (Alvogyl™). CONCLUSION: The improvement in Gu's biological properties in vitro and the rapid alveolar repair in comparison with Alvogyl™ in vivo demonstrated the benefits of the Gu/ßcd complex as a future alternative for the treatment of DS.

Jararhagin, a snake venom metalloprotease-disintegrin, activates the Rac1 GTPase and stimulates neurite outgrowth in neuroblastoma cells.

It has been shown previously that the snake venom metalloprotease-disintegrin jararhagin stimulates cell migration and cytoskeletal rearrangement, independently of its effects on cellular adhesion but possibly associated with the activation of small GTP-binding proteins from the Rho family [Costa, E.P., Santos, M.F., 2004. Toxicon 44(8), 861-870.] Here we show that jararhagin stimulates spreading, actin dynamics and neurite outgrowth in neuroblastoma cells, and that this effect is accompanied by the translocation of the Rac1 small GTPase to the membrane fraction, suggesting its activation. Stimulation of neurite outgrowth was observed within minutes and was dependent on the proteolytic activity of the toxin. These results suggest that jararhagin may stimulate neuronal differentiation, being a potential tool for neuronal regeneration studies.

Role of microRNAs in endocrine cancer metastasis.

The deregulation of transcription and processing of microRNAs (miRNAs), as well as their function, has been involved in the pathogenesis of several human diseases, including cancer. Despite advances in therapeutic approaches, cancer still represents one of the major health problems worldwide. Cancer metastasis is an aggravating factor in tumor progression, related to increased treatment complexity and a worse prognosis. After more than one decade of extensive studies of miRNAs, the fundamental role of these molecules in cancer progression and metastasis is beginning to be elucidated. Recent evidences have demonstrated a significant role of miRNAs on the metastatic cascade, acting either as pro-metastatic or anti-metastatic. They are involved in distinct steps of metastasis including epithelial-to-mesenchymal transition, migration/invasion, anoikis survival, and distant organ colonization. Studies on the roles of miRNAs in cancer have focused mainly on two fronts: the establishment of a miRNA signature for different tumors, which may aid in early diagnosis using these miRNAs as markers, and functional studies of specific miRNAs, determining their targets, function and regulation. Functional miRNA studies on endocrine cancers are still scarce and represent an important area of research, since some tumors, although not frequent, present a high mortality rate. Among the endocrine tumors, thyroid cancer is the most common and best studied. Several miRNAs show lowered expression in endocrine cancers (i.e. miR-200s, miR-126, miR-7, miR-29a, miR-30a, miR-137, miR-206, miR-101, miR-613, miR-539, miR-205, miR-9, miR-195), while others are commonly overexpressed (i.e. miR-21, miR-183, miR-31, miR-let7b, miR-584, miR-146b, miR-221, miR-222, miR-25, miR-595). Additionally, some miRNAs were found in serum exosomes (miR-151, miR-145, miR-31), potentially serving as diagnostic tools. In this review, we summarize studies concerning the discovery and functions of miRNAs and their regulatory roles in endocrine cancer metastasis, which may contribute for the finding of novel therapeutic targets. The review focus on miRNAs with at least some identified targets, with established functions and, if possible, upstream regulation.

Long- and short-term diabetes mellitus type 1 modify young and elder rat salivary glands morphology.

OBJECTIVE: In this study we performed a temporal analysis of the effects of Diabetes Mellitus on morphology and laminin deposition in salivary glands of young (2 months-old) and aging (12 months-old) male Wistar rats, using immunohistochemistry. MATERIALS AND METHODS: The animals were divided in control and diabetic (Streptozotocin induced) groups and euthanized after short and long-term diabetes induction. RESULTS: Short-term induction led to vacuolization of parotid acinar cells and increased laminin deposition in both animal ages. In young rats, no difference was observed between short or long-term diabetes regarding laminin deposition, but parotid acinar cells vacuolization was more discrete after long-term diabetes. A slight decrease of submandibular gland convoluted granular ducts was observed in young and elder diabetic animal ages. In diabetic aging rats was observed an increase of laminin content only in the parotid gland. CONCLUSIONS: These results suggest that some Diabetes Mellitus effects on salivary glands are not progressive over time, possibly due to the existence of adaptive mechanisms in response to chronic hyperglycemia. They also show that the duration of the disease was more relevant to the morphological effects than the age, although it is known that aging per se affects salivary gland morphology and function.