Cell sheet produced from periodontal ligament stem cells activated by PAR1 improves osteogenic differentiation.

Periodontal regeneration is a challenge, and tissue engineering based on periodontal ligament stem cells (PDLSCs) has been shown to be a promising alternative to this process. However, the need for scaffolds has limited the therapeutic use of PDLSCs. In this context, scaffold-free tissue engineering using the cell sheet (CS) technique has been developed as an alternative approach to improve tissue regeneration. Previously, we showed that Protease-activated receptor-1 (PAR1) can regulate PDLSCs. Herein, we evaluate whether PAR1 influences osteogenesis in CSs produced from PDLSCs, without the use of scaffolds. PDLSCs were isolated and immunophenotyped. Then, CSs were obtained by supplementing the culture medium with ascorbic acid (50 µg/mL), and PAR1 was activated through its agonist peptide (100 nM). Scaffold-free 3D CSs were successfully produced from PDLSCs, and they showed higher proliferation potential than isolated PDLSCs. Also, PAR1 activation decreased senescence and improved osteogenic differentiation of CSs by increasing mineralized nodule deposition and alkaline phosphatase concentration; PAR1 also modulated osteogenic markers at the gene and protein levels. We further demonstrated that this effect was regulated by Wnt, TGF-ßI, MEK, p38 MAPK, and FGF/VEGF signaling pathways in PDLSCs (p < 0.05%). Overall, PAR1 activation increased osteogenic activity in CSs, emerging as a promising scaffold-free therapeutic approach for periodontal regeneration.

Avances en endodoncia regenerativa: reporte de caso con uso de la membrana amniótica humana / Advances in regenerative endodontics: report of a case using a human amniotic membrane

Los procedimientos endodónticos regenerativos (REPs) representan una evolución significativa en el campo de la endodoncia, buscando no sólo tratar la infección o lesión presente en el diente, sino tam-bién promover la regeneración de los tejidos denta-rios afectados. El presente caso clínico muestra un incisivo lateral superior izquierdo con apexogénesis incompleta y diagnóstico de absceso alveolar crónico reagudizado en una paciente de 22 años, en el que se aplicó un procedimiento de endodoncia regenerativa (REPs). La estrategia terapéutica elegida se basó en los principios de ingeniería tisular, incorporando la novedosa aplicación de la membrana amniótica hu-mana liofilizada esterilizada como andamio bioactivo intraconducto. Las evaluaciones clínicas, radiográ-ficas y tomográficas a corto, mediano y largo plazo revelaron el éxito de la terapia. La resolución exitosa mostró en los controles a la pieza dentaria asintomá-tica, con una notable remisión de la patología apical, aumento de la longitud radicular y disminución del calibre apical. Se ha podido destacar la eficacia de los REPs, con una exitosa aplicabilidad de la membra-na amniótica como andamio innovador (AU)

Regenerative endodontic procedures (REPs) represent a significant evolution in the field of endodontics, aiming not only to address the infection or injury within the tooth, but also to promote the regeneration of the affected dental tissues. In this clinical case, an upper left lateral incisor with incomplete apexogenesis and diagnosis of acute exacerbation of a chronic periapical lesion in a 22-year-old patient is presented. A regenerative endodontic procedure (REPs) was applied. The chosen therapeutic strategy was based on tissue engineering principles, incorporating the innovative use of sterilized lyophilized human amniotic membrane as an intraconduct bioactive scaffold. Clinical, radiographic, and tomographic assessments at short, medium, and long-term follow-up revealed the success of the therapy. Successful resolution demonstrated an asymptomatic tooth in the follow-up, with a notable resolution of apical pathology, increased root length, and decreased apical caliber. The effectiveness of REPs has been highlighted, demonstrating the successful applicability of amniotic membrane as an innovative scaffold (AU)

Dental pulp and apical papilla cells senescence: causes, consequences, and prevention.

Dental pulp under physiological conditions has a defense function, repair capacity, and important mechanisms in pathological processes. In addition, the dental papilla is involved in important defense processes and an essential function in the pulp revascularization process. It is known that dental pulp and apical papilla undergo a natural aging process, in addition to stressful situations such as bruxism, inflammation, and infections. Both aging and stressful situations can lead to cellular senescence. Some evidence indicates that the changes resulting from this cellular state can directly affect the efficiency of cells in these tissues and affect conservative and regenerative clinical treatments. Thus, it is necessary to understand the causes and consequences of cellular senescence in addition to the development of methods for senescence prevention. This review aims to provide an overview of possible causes and consequences of senescence in dental pulp and stem cells from apical papilla and discusses possible methods to prevent this cellular state.

A Review of Stem Cell Technology Targeting Hepatocyte Growth as an Alternative to Organ Transplantation.

Currently, the only feasible option for patients with progressive and/or end-stage organ degeneration is to undergo transplantation. Due to the growing unmatched demand of available organ donors and, as a consequence, the continuous growth of patients' waiting lists, the development of new tissue engineering technologies is a relevant need. In this chapter, we will focus on the liver as a model organ to discuss contemporary tissue engineering strategies. Induced pluripotent cells are an attractive alternative to serve as a cell source for tissue engineering applications due to their pluripotency, the potentiality to generate autologous transplantation, and for their high proliferation rate. Among the main liver tissue engineering technologies, 3D bioprinting, hepatic organoids, and decellularization/recellularization of biological matrixes have grown much attention as alternatives to derive functional liver grafts. Thus, this chapter will discuss how recent publications have demonstrated the use of induced pluripotent cells in the development of the aforementioned technologies. Bioprinting is an additive manufacturing biofabrication process where cells are dispersed within a matrix formulation (i.e., bioink) and extruded in a modified 3D-printer. Polymers within bioink can be cross-linked to increase stiffness. Hepatic spheroids showed greater viability and liver function, due to preserved epithelial phenotype over time. Organoid is multi-lineage tissue constructs derived from a stem cell that recapitulates the early stages of organogenesis. The influence of cellular composition of non-parenchymal cells using induced pluripotent-derived cells or primary adult cells for hepatic organoid formation was recently tested. Decellularization is a process where harvested tissues or organs are washed with a detergent-based solution, to lyse and remove all cellular components. The final product is an extracellular scaffold with preserved tissue vasculature and ultra-structure, which can be used for subsequent recellularization with recipient cells. This chapter sheds light on recent works on the use of induced pluripotent-derived cells for liver tissue engineering approaches and on how such technologies could potentially generate therapeutic alternatives for patients on waiting lists for liver transplantation.

Triiodothyronine does not influence in vitro chondrogenic differentiation of adipose tissue-derived stem cells from young female rat / Triiodotironina não influencia na diferenciação condrogênica de células tronco do tecido adipose de ratas jovens

The objective of this study was to investigate the in vitro action of triiodothyronine (T3) on the chondrogenic differentiation of adipose tissue-derived stem cells (ASCs) of female rats, with different time periods and doses. ASCs were extracted from female Wistar rats and were cultured in chondrogenic medium with and without the presence of T3. Five groups were established: 1) ASCs without T3; and 2,3,4,5) ASCs with 0.01, 1, 100 and 1,000 nM T3, respectively). After 7, 14 and 21 days, cell morphology, chondrogenic matrix formation, and expression of Sox9, aggrecan, collagen II, and collagen X were evaluated. The Student-Newman-Keuls test was used. ASCs showed CD54, CD73, and CD90 before chondrogenic differentiation. The hormone treatment did not alter chondrogenic matrix formation, Sox9 expression at 14 or 21 days, or expression of collagen II or collagen X at any time. However, the 0.01, 1, and 1000 nM T3 doses decreased Sox9 expression at 7 days. In conclusion, chondrogenic differentiation of ASCs of female rats is not influenced by T3.

O objetivo do presente trabalho foi verificar o efeito in vitro da triiodotironina (T3) na diferenciação condrogênica de células tronco mesenquimais do tecido adiposo (CTM-TA) de ratas, durante vários períodos e em várias doses. CTM-TA foram coletadas de ratas Wistar e cultivadas em meio condrogênico com ou sem a presença de T3. Constitui-se cinco grupos: 1) CTM-TA sem T3; e 2,3,4,5) CTM-TA com T3 (0,01; 1; 100 e 1000 nM, respectivamente). Após sete, 14 e 21 dias, foram avaliados morfologia celular, formação de matriz condrogênica e expressão de Sox9, agrecano, colágeno II e colágeno X. Para as análises foi utilizado o teste de Student Newman Keuls. CTM-TA expressaram CD54, CD73 e CD90 antes da diferenciação condrogênica. O tratamento hormonal não alterou a formação de matriz condrogênica e a expressão de Sox9 aos 14 e 21 dias e expressão dos colágenos II e X em nenhum dos períodos avaliados. No entanto, as doses de 0,01; 1 e 1000 nM T3 diminuíram a expressão de Sox9 aos 7 dias. Conclui-se que a diferenciação condrogênica de CTM-TA de ratas não é influenciada pela T3.

Apical contacts stemming from incomplete delamination guide progenitor cell allocation through a dragging mechanism.

The developmental strategies used by progenitor cells to allow a safe journey from their induction place towards the site of terminal differentiation are still poorly understood. Here, we uncovered a mechanism of progenitor cell allocation that stems from an incomplete process of epithelial delamination that allows progenitors to coordinate their movement with adjacent extra-embryonic tissues. Progenitors of the zebrafish laterality organ originate from the superficial epithelial enveloping layer by an apical constriction process of cell delamination. During this process, progenitors retain long-lasting apical contacts that enable the epithelial layer to pull a subset of progenitors on their way to the vegetal pole. The remaining delaminated cells follow the movement of apically attached progenitors by a protrusion-dependent cell-cell contact mechanism, avoiding sequestration by the adjacent endoderm, ensuring their collective fate and allocation at the site of differentiation. Thus, we reveal that incomplete delamination serves as a cellular platform for coordinated tissue movements during development.

Constrained chromatin accessibility in PU.1-mutated agammaglobulinemia patients.

The pioneer transcription factor (TF) PU.1 controls hematopoietic cell fate by decompacting stem cell heterochromatin and allowing nonpioneer TFs to enter otherwise inaccessible genomic sites. PU.1 deficiency fatally arrests lymphopoiesis and myelopoiesis in mice, but human congenital PU.1 disorders have not previously been described. We studied six unrelated agammaglobulinemic patients, each harboring a heterozygous mutation (four de novo, two unphased) of SPI1, the gene encoding PU.1. Affected patients lacked circulating B cells and possessed few conventional dendritic cells. Introducing disease-similar SPI1 mutations into human hematopoietic stem and progenitor cells impaired early in vitro B cell and myeloid cell differentiation. Patient SPI1 mutations encoded destabilized PU.1 proteins unable to nuclear localize or bind target DNA. In PU.1-haploinsufficient pro-B cell lines, euchromatin was less accessible to nonpioneer TFs critical for B cell development, and gene expression patterns associated with the pro- to pre-B cell transition were undermined. Our findings molecularly describe a novel form of agammaglobulinemia and underscore PU.1's critical, dose-dependent role as a hematopoietic euchromatin gatekeeper.

Telocytes of the male urogenital system: Interrelationships, possible functions, and pathological implications.

The male urogenital system is composed of the reproductive system and the urinary tract; they have an interconnected embryonic development and share one of their anatomical components, the urethra. This system has a highly complex physiology deeply interconnected with the circulatory and nervous systems, as well as being capable of adapting to environmental variations; it also undergoes changes with aging and, in the case of the reproductive system, with seasonality. The stroma is an essential component in this physiological plasticity and its complexity has increased with the description in the last decade of a new cell type, the telocyte. Several studies have demonstrated the presence of telocytes in the organs of the male urogenital system and other systems; however, their exact function is not yet known. The present review addresses current knowledge about telocytes in the urogenital system in terms of their locations, interrelationships, possible functions and pathological implications. It has been found that telocytes in the urogenital system possibly have a leading role in stromal tissue organization/maintenance, in addition to participation in stem cell niches and an association with the immune system, as well as specific functions in the urogenital system, lipid synthesis in the testes, erythropoiesis in the kidneys and the micturition reflex in the bladder. There is also evidence that telocytes are involved in pathologies in the kidneys, urethra, bladder, prostate, and testes.

Farnesoid X Receptor Activation Impairs Liver Progenitor Cell-Mediated Liver Regeneration via the PTEN-PI3K-AKT-mTOR Axis in Zebrafish.

BACKGROUND AND AIMS: Following mild liver injury, pre-existing hepatocytes replicate. However, if hepatocyte proliferation is compromised, such as in chronic liver diseases, biliary epithelial cells (BECs) contribute to hepatocytes through liver progenitor cells (LPCs), thereby restoring hepatic mass and function. Recently, augmenting innate BEC-driven liver regeneration has garnered attention as an alternative to liver transplantation, the only reliable treatment for patients with end-stage liver diseases. Despite this attention, the molecular basis of BEC-driven liver regeneration remains poorly understood. APPROACH AND RESULTS: By performing a chemical screen with the zebrafish hepatocyte ablation model, in which BECs robustly contribute to hepatocytes, we identified farnesoid X receptor (FXR) agonists as inhibitors of BEC-driven liver regeneration. Here we show that FXR activation blocks the process through the FXR-PTEN (phosphatase and tensin homolog)-PI3K (phosphoinositide 3-kinase)-AKT-mTOR (mammalian target of rapamycin) axis. We found that FXR activation blocked LPC-to-hepatocyte differentiation, but not BEC-to-LPC dedifferentiation. FXR activation also suppressed LPC proliferation and increased its death. These defects were rescued by suppressing PTEN activity with its chemical inhibitor and ptena/b mutants, indicating PTEN as a critical downstream mediator of FXR signaling in BEC-driven liver regeneration. Consistent with the role of PTEN in inhibiting the PI3K-AKT-mTOR pathway, FXR activation reduced the expression of pS6, a marker of mTORC1 activation, in LPCs of regenerating livers. Importantly, suppressing PI3K and mTORC1 activities with their chemical inhibitors blocked BEC-driven liver regeneration, as did FXR activation. CONCLUSIONS: FXR activation impairs BEC-driven liver regeneration by enhancing PTEN activity; the PI3K-AKT-mTOR pathway controls the regeneration process. Given the clinical trials and use of FXR agonists for multiple liver diseases due to their beneficial effects on steatosis and fibrosis, the detrimental effects of FXR activation on LPCs suggest a rather personalized use of the agonists in the clinic.

Rabbit vomeronasal organ-derivered cells have mesenchymal profile and neuronal commitment / Las células derivadas del órgano vomeronasal del conejo tienen perfil mesenquimatoso y compromiso neuronal

SUMMARY: The vomeronasal organ (VNO) is an accessory organ involved on the olfactory pathway, that detects pheromones and emits signals in order to modulate social and reproductive behavior. The VNO stem cells replace neurons throughout life. The aim of this study was to isolate and characterize cells derived from the vomeronasal organ from New Zealand rabbits. Five male rabbits with 120 days were used for cell isolation and culture. Results: VNO-derived cells presented labelling for proliferation (PCNA), undifferentiated profile (Nanog), neuronal (GFAP), mesenchymal stem cells (CD73, CD90 and CD105 and Stro-1). Also, presence of cytoskeletal (Vimentin, b-tubulin and CK-18) and absence of hematopoietic markers (CD34, CD117 and CD45) both by immunofluorescence and flow cytometry. By PCR it was possible to verify the expression of some undifferentiated profile (Oct-4), neuronal (Nestin) and mesenchymal (CD73, CD105 and Vimentin) genes. Functionally, VNO-derived cells differentiate in vitro into adipocytes, osteocytes and chondrocytes, and presented no tumorigenic potential when injected to Balb/c nu/nu mice. In conclusion, the rabbit VNO-derived cells have a profile that could be supportive to VNO olfactory/neuroreceptor epithelium by delivering factors to epithelial turnover or even by differentiation into epithelial cells to replacement of commissural epithelium.

RESUMEN: El órgano vomeronasal (OVN) es un órgano accesorio de la vía olfatoria, que detecta feromonas y emite señales que afectan la modulación del comportamiento social y reproductivo. Las células madre OVN reemplazan las neuronas durante toda la vida. El objetivo de este estudio fue aislar y caracterizar células derivadas del órgano vomeronasal de conejos raza Nueva Zelanda. Para el aislamiento y el cultivo celular se utilizaron cinco conejos machos con una edad de 120 días. Las células del OVN presentaron etiquetado para la proliferación (PCNA), un perfil indiferenciado (Nanog), neuronal (GFAP), células madre mesenquimales (CD73, CD90 y CD105 y Stro-1). Además, se ob- servó presencia de citoesqueleto (Vimentina, β-tubulina y CK-18) y ausencia de marcadores hematopoyéticos (CD34, CD117 y CD45) tanto por inmunofluorescencia como por citometría de flujo. Me- diante PCR fue posible verificar la expresión de algunos genes de perfil indiferenciado (Oct-4), neuronal (Nestin) y mesenquimatoso (CD73, CD105 y Vimentin). Las células derivadas del OVN se diferencian in vitro en adipocitos, osteocitos y condrocitos, y no presentan un potencial tumorigénico al ser infiltrados en ratones Balb / c nu / nu. En conclusión, las células derivadas de OVN de conejo tienen un perfil que podría ser compatible con el epitelio olfatorio / neurorreceptor de OVN transmitiendo factores al recambio epitelial o incluso mediante la diferenciación en células epiteliales para reemplazar el epitelio comisural.

Quantitative characterization of proliferative cells subpopulations in the hilus of the hippocampus of adult Wistar rats: an integrative study.

The hilus plays an important role modulating the excitability of the hippocampal dentate gyrus (DG). It also harbors proliferative cells whose proliferation rate is modified during pathological events. However, the characterization of these cells, in terms of cellular identity, lineage, and fate, as well as the morphology and proportion of each cell subpopulation has been poorly studied. Therefore, a deeper investigation of hilar proliferative cells might expand the knowledge not only in the physiology, but in the pathophysiological processes related to the hippocampus too. The aim of this work was to perform an integrative study characterizing the identity of proliferative cells populations harbored in the hilus, along with morphology and proportion. In addition, this study provides comparative evidence of the subgranular zone (SGZ) of the DG. Quantified cells included proliferative, neural precursor, Type 1, oligodendrocyte progenitor (OPCs), neural progenitor (NPCs), and proliferative mature astrocytes in the hilus and SGZ of Wistar adult rats. Our results showed that 84% of the hilar proliferative cells correspond to neural precursor cells, OPCs and NPCs being the most abundant at 54 and 45%, respectively, unlike the SGZ, where OPCs represent only 11%. Proliferative mature astrocytes and Type 1-like cells were rarely observed in the hilus. Together, our results lay the basis for future studies focused on the lineage and fate of hilar proliferative cells and suggest that the hilus could be relevant to the formation of new cells that modulate multiple physiological processes governed by the hippocampus.

Renal Progenitor Cells Have Higher Genetic Stability and Lower Oxidative Stress than Mesenchymal Stem Cells during In Vitro Expansion.

In vitro senescence of multipotent cells has been commonly associated with DNA damage induced by oxidative stress. These changes may vary according to the sources of production and the studied lineages, which raises questions about the effect of growing time on genetic stability. This study is aimed at evaluating the evolution of genetic stability, viability, and oxidative stress of bone marrow mesenchymal stem cells (MSCBMsu) and renal progenitor cells of the renal cortex (RPCsu) of swine (Sus scrofa domesticus) in culture passages. P2, P5, and P9 were used for MSCBMsu and P1, P2, and P3 for RPCsu obtained by thawing. The experimental groups were submitted to MTT, apoptosis and necrosis assays, comet test, and reactive substance measurements of thiobarbituric acid (TBARS), nitrite, reduced glutathione (GSH), and catalase. The MTT test curve showed a mean viability of 1.14 ± 0.62 and 1.12 ± 0.54, respectively, for MSCBMsu and RPCsu. The percentages of MSCBMsu and RPCsu were presented, respectively, for apoptosis, an irregular and descending behavior, and necrosis, ascending and irregular. The DNA damage index showed higher intensity among the MSCBMsu in the P5 and P9 passages (p < 0.05). In the TBARS evaluation, there was variation among the lines of RPCsu and MSCBMsu, presenting the last most significant variations (p < 0.05). In the nitrite values, we identified only among the lines, in the passages P1 and P2, with the highest averages displayed by the MSCBMsu lineage (p < 0.05). The measurement of antioxidant system activity showed high standards, identifying differences only for GSH values, in the RPCsu lineage, in P3 (p < 0.05). This study suggests that the maintenance of cell culture in the long term induces lower regulation of oxidative stress, and RPCsu presents higher genetic stability and lower oxidative stress than MSCBMsu during in vitro expansion.

Ovarian tissue vitrification is more efficient than slow freezing to preserve ovarian stem cells in CF-1 mice.

OBJECTIVE: The aim of this study was to investigate the efficacy of protocols for mice ovary cryopreservation to compare the differences in Mouse Vasa Homologue expression (a germline cell marker) and ovarian viability after vitrification or slow freezing. METHODS: Female CF1 mice aged 40-45 days were randomly divided into three groups: Control, vitrification or slow freezing. Their ovaries were surgically removed, rinsed in saline solution and cryopreserved. For vitrification, we used a commercial protocol and for slow freeze, we used 1.5 M ethylene glycol (EG) as cryoprotectant. After that, the ovaries were processed for histological an immunohistochemical analysis, and counting of primordial, primary, pre-antral and antral follicles. RESULTS: No significant difference was found in the proportion of high-quality primordial, primary and pre-antral follicles after thawing/warming in the slow freezing and vitrification groups. The immunohistochemistry for MVH antibody demonstrated that the slow freeze group had a higher number of unmarked cells (p=0.012), indicating a harmful effect on the MVH expression in the ovarian tissue, where the cell structure is complex. CONCLUSION: Although both protocols indicated similar results in the histological analysis of follicular counts, the vitrification protocol was significantly better to preserve ovarian stem cells, an immature germ cell population. These cells are able to self-renew having regeneration potential, and may be effective for the treatment of ovarian failure and consequently infertility.

Deciphering the role of miR-71 in Echinococcus multilocularis early development in vitro.

Echinococcosis represents a major public health problem worldwide and is considered a neglected disease by the World Health Organization. The etiological agents are Echinococcus tapeworms, which display elaborate developmental traits that imply a complex control of gene expression. MicroRNAs (miRNAs), a class of small regulatory RNAs, are involved in the regulation of many biological processes such as development and metabolism. They act through the repression of messenger RNAs (mRNAs) usually by binding to the 3' untranslated region (3'UTR). Previously, we described the miRNome of several Echinococcus species and found that miRNAs are highly expressed in all life cycle stages, suggesting an important role in gene expression regulation. However, studying the role of miRNAs in helminth biology remains a challenge. To develop methodology for functional analysis of miRNAs in tapeworms, we performed miRNA knockdown experiments in primary cell cultures of Echinococcus multilocularis, which mimic the development of metacestode vesicles from parasite stem cells in vitro. First, we analysed the miRNA repertoire of E. multilocularis primary cells by small RNA-seq and found that miR-71, a bilaterian miRNA absent in vertebrate hosts, is one of the top five most expressed miRNAs. Using genomic information and bioinformatic algorithms for miRNA binding prediction, we found a high number of potential miR-71 targets in E. multilocularis. Inhibition of miRNAs can be achieved by transfection of antisense oligonucleotides (anti-miRs) that block miRNA function. To this end, we evaluated a variety of chemically modified anti-miRs for miR-71 knockdown. Electroporation of primary cells with 2'-O-methyl modified anti-miR-71 led to significantly reduced miR-71 levels. Transcriptomic analyses showed that several predicted miR-71 targets were up-regulated in anti-miR-treated primary cells, including genes potentially involved in parasite development, host parasite interaction, and several genes of as yet unknown function. Notably, miR-71-silenced primary cell cultures showed a strikingly different phenotype from control cells and did not develop into fully mature metacestodes. These findings indicate an important function of miR-71 in Echinococcus development and provide, for the first time, methodology to functionally study miRNAs in a tapeworm.

Hiposialia y Xerostomía Post Irradiación: Terapias Innovadoras en el Campo Biomolecular / Hyposialia and Xerostomy Post Irradiation: Innovative Therapies in the Biomolecular Field

Las glándulas salivales humanas pueden ser gravemente lesionadas por la radioterapia utilizada contra neoplasias de cabeza y cuello, produciendo hiposialia y xerostomía, las cuales afectan la salud oral y sistémica, mermando la calidad de vida de la persona. Los tratamientos convencionales actuales están diseñados para disminuir los síntomas, sin actuar sobre los cambios fisiopatológicos que se dan a nivel glandular. Esta revisión intenta analizar aquellas terapias preventivas y/o curativas que están desarrollándose en el campo biomolecular y que tienen un futuro prometedor por sus características innovadoras: terapia génica, terapia con células madre y terapia con factores de crecimiento. Se evidencia un aporte adicional de la nanotecnología, la cual está mejorando las vías de aplicación de los tratamientos.

Human salivary glands can be seriously injured by the radiotherapy used against head and neck neoplasms, producing hyposialia and xerostomy, which affect oral and systemic health, diminishing the person's quality of life. Current conventional treatments are designed to reduce symptoms, without acting on the pathophysiological changes that occur at the glandular level. This review attempts to analyze those preventive and /or curative therapies that are developing in the biomolecular field and that have a promising future due to their innovative features: Gene therapy, stem cell therapy and growth factor therapy. An additional contribution of nanotechnology is evident, which is improving the routes of treatment application.

Biodentine Induce Proteínas Apoptóticas Caspasa 3 y PARP-1 en Células de la Pulpa Dental Humana / Biodentine Induces Apoptotic Proteins Caspase 3 and PARP - 1 on Human Dental Pulp Cells

RESUMEN: Las patologías pulpares han sido un verdadero reto para la odontología principalmente por su tratamiento. Actualmente, existen numerosos biomateriales en el mercado que reportan tener propiedades inherentes en los tejidos dentarios. Sin embargo, diferentes estudios sobre múltiples líneas celulares expuestas a estos biomateriales demuestran resultados controversiales como biocompatiblidad y citotoxicidad celular. Biodentine, es un cemento endodóntico en base a silicatos cálcico de múltiples aplicaciones, que prestaría propiedades de biocompatibilidad como bioactividad celular, características que le permitirían incluso ser utilizado en contacto directo con la pulpa dental. El objetivo de este estudio es la evaluación in-vitro de Biodentine, sobre cultivos de células de la pulpa dental humana (CCPDH). Se prepararon discos de cemento de Biodentine™ de 2 x 6 mm, los que se expusieron a cultivos de células aisladas de la pulpa dental humana. Luego de 24, 48 y 72 horas de exposición, se realizaron ensayos de viabilidad celular utilizando el método colorimétrico MTT. También se realizaron ensayos de expresión proteica de dos proteínas involucradas en la vía de señalización de la apoptosis celular: Caspasa - 3 clivada y Poli (ADP-Ribosa) Polimerasa, PARP - 1. Existen diferencias estadísticamente significativas (p<0,05) en los ensayos de viabilidad celular entre las células expuestas a Biodentine y el grupo control, como también a medida que aumenta el tiempo de exposición (p<0,05). Por otra parte, también existen diferencias significativas (p<0,05) en la expresión de PARP- 1 en los grupos sometidos a Biodentine. Los resultados obtenidos en este estudio demuestran que Biodentine genera citotoxicidad celular en cultivos celulares de pulpa dental humana, por disminución de la viabilidad celular como por la expresión de proteínas apoptóticas. Es por esto que la utilización de este biomaterial debería ser estudiado y considerarse en cada caso clínico, especialmente como recubridor pulpar directo.

ABSTRACT: Oral pathologies have been a real challenge for dentistry, mainly due to its treatment. Currently, there are numerous biomaterials on the market that may present inherent properties in dental tissues. However, studies on multiple cell lines are based on biocompatible results such as biocompatibility and cellular cytotoxicity. Biodentine is endodontic cement based on calcium silicates of multiple applications, which would provide biocompatibility properties as cellular bioactivity, characteristics that will allow it to be used in direct contact with the dental pulp. The objective of this study is the in vitro evaluation of Biodentine, on cultures of cells of the human dental pulp (HDPC). Biodentine cement disks of 2 x 6 mm were prepared, and HDPC culture plates were introduced. After 24, 48 and 72 hours of exposure, cell viability tests were performed using the MTT colorimetric method. On the other hand, protein expression assays of two proteins involved in the signaling pathway of cell apoptosis Caspase-3 cleaved (cas-3 clv) and PARP-1 are carried out. There are statistically significant differences (p <0,05) in the cell viability tests between Biodentine and control group, as well as the exposure time increases (p <0,05). Otherwise, there are also significant differences (p <0,05) in the expression of PARP-1 in the groups, sometimes a Biodentine. The results in this study that Biodentine generates a cellular cytotoxicity in HDPC cultures, therefore, cell viability as the expression of apoptotic proteins. This is why the use of this biomaterial should be studied for each particular clinical case, especially as a direct pulp capping agent.

Mechanisms Underlying Cell Therapy in Liver Fibrosis: An Overview.

Fibrosis is a common feature in most pathogenetic processes in the liver, and usually results from a chronic insult that depletes the regenerative capacity of hepatocytes and activates multiple inflammatory pathways, recruiting resident and circulating immune cells, endothelial cells, non-parenchymal hepatic stellate cells, and fibroblasts, which become activated and lead to excessive extracellular matrix accumulation. The ongoing development of liver fibrosis results in a clinically silent and progressive loss of hepatocyte function, demanding the constant need for liver transplantation in clinical practice, and motivating the search for other treatments as the chances of obtaining compatible viable livers become scarcer. Although initially cell therapy has emerged as a plausible alternative to organ transplantation, many factors still challenge the establishment of this technique as a main or even additional therapeutic tool. Herein, the authors discuss the most recent advances and point out the corners and some controversies over several protocols and models that have shown promising results as potential candidates for cell therapy for liver fibrosis, presenting the respective mechanisms proposed for liver regeneration in each case.

Control of stem cell activity in the carpel margin meristem (CMM) in Arabidopsis.

KEY MESSAGE: Overview of the current understanding of the molecular mechanisms that regulate meristem activity in the CMM compared to the SAM. Meristems are undifferentiated cells responsible for post-embryonic plant development. The meristems are able to form new organs continuously by carefully balancing between stem cell proliferation and cell differentiation. The plant stem cell niche in each meristem harbors the stem cells that are important to maintain each meristem. The shoot apical meristem (SAM) produces all above-parts of a plant and the molecular mechanisms active in the SAM are actively studied since many years, and models are available. During the reproductive phase of the plant, the inflorescence meristem gives rise to floral meristems, which give rise to the flowers. During floral development, the gynoecium forms that contains a new meristem inside, called the carpel margin meristem (CMM). In Arabidopsis, the gynoecium consists out of two fused carpels, where the CMM forms along the fused carpel margins. In this review, we focus on the molecular mechanisms taking place in the CMM, and we discuss similarities and differences found in the SAM.

Biomechanical evaluation of tendon regeneration with adipose-derived stem cell.

The use of Adipose-Derived Stem Cells (ADSC) has been presented as a new alternative for tendon reconstruction. Have been admitted that ADSCs are related to better outcomes when used in tendon healing. This research was designed to apply the potential of ADSCs in tendon healing. Flexor digitorum superficialis tendon lesion was performed on both legs of eleven New Zealand rabbits and them, at the same time, treated as follows: Suture alone (Group III - Suture, n:10), suture associated with ADSC (Group IV - Suture + ADSC, n:10) or without suture (Group II - SHAN, n:2). At four weeks after the tendon surgery, the animal was euthanized, and the tendon evaluated (biomechanically and macroscopically). We used 5 additional New Zealand rabbits in the control group "Group I - Control, n:10". In the macroscopic evaluation, the group with ADSC presented a more homogeneous gross morphology compared with the group III. Biomechanical testing showed a lower ultimate tensile load, stiffness and a higher cross-sectional area in the group III and IV compared with the control group. The group with ADSC showed a greater ultimate tensile load, a larger cross-sectional area and bigger deformation at the ultimate tensile load when compared to the group without ADSC. In general terms, the use of ADSCs in tendon healing have biomechanical advantages compared to the non-use of ADSCs at 4 weeks after surgery. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1281-1286, 2019.

Progesterone effects on oligodendrocyte differentiation in injured spinal cord.

Spinal cord lesions result in chronic demyelination as a consequence of secondary injury. Although oligodendrocyte precursor cells proliferate the differentiation program fails. Successful differentiation implies progressive decrease of transcriptional inhibitors followed by upregulation of activators. Progesterone emerges as an anti-inflammatory and pro-myelinating agent which improves locomotor outcome after spinal cord injury. In this study, we have demonstrated that spinal cord injury enhanced oligodendrocyte precursor cell number and decreased mRNA expression of transcriptional inhibitors (Id2, Id4, hes5). However, mRNA expression of transcriptional activators (Olig2, Nkx2.2, Sox10 and Mash1) was down-regulated 3 days post injury. Interestingly, a differentiation factor such as progesterone increased transcriptional activator mRNA levels and the density of Olig2- expressing oligodendrocyte precursor cells. The differentiation program is regulated by extracellular signals which modify transcriptional factors and epigenetic players. As TGFß1 is a known oligodendrocyte differentiation factor which is regulated by progesterone in reproductive tissues, we assessed whether TGFß1 could mediate progesterone remyelinating actions after the lesion. Notwithstanding that astrocyte, oligodendrocyte precursor and microglial cell density increased after spinal cord injury, the number of these cells which expressed TGFß1 remained unchanged regarding sham operated rats. However, progesterone treatment increased TGFß1 mRNA expression and the number of astrocytes and microglial TGFß1 expressing cells which would indirectly enhance oligodendrocyte differentiation. Therefore, TGFß1 arises as a potential mediator of progesterone differentiating effects on oligodendrocyte linage.