RESUMO
The methodologies applicable for the evaluation of periodontal associated diseases are constantly evolving to provide quick, realistic, and scientifically proven results. Trends in the past followed a clinical evaluation of periodontal tissues and radiographic-based reports that formed the foundation for detection of diseases involving the structures supporting the teeth. As the confines and limitations of conventional strategies became obvious over the passage of time, hand in hand variety of techniques have evolved and experimentally justified. These improvisations are based on an improved understanding of the periodontal-pathogenic cascade. Periodontal pathogenesis and a paradigm shift from disease understanding to disease prevention and treatment entail few prerequisites that demand the objectivity of diagnostics procedure that includes sensitivity and specificity along with an explanation of the intensity of the disease, Gingival crevicular fluid an oral bio-fluid resides in the close proximity with gingival tissues have been widely used to understand and differentiate the periodontal health and diseased status. The biomarkers present in the GCF can be a reliable tool to detect the minute changes seen in the disease processes. The GCF consists of various host and bacterial-derived products as well as biomarkers which in turn can be evaluated for the diagnosis, prognosis as well as management of the periodontal disease. Thus, the review aims at describing GCF as a potential oral biofluid helpful in differentiating periodontal health and disease status.
Assuntos
Líquido do Sulco Gengival/química , Doenças Periodontais/diagnóstico , Biomarcadores/análise , HumanosRESUMO
Desmoglein 3 (Dsg3) plays a crucial role in cell-cell adhesion and tissue integrity. Increasing evidence suggests that Dsg3 acts as a regulator of cellular mechanotransduction, but little is known about its direct role in mechanical force transmission. The present study investigated the impact of cyclic strain and substrate stiffness on Dsg3 expression and its role in mechanotransduction in keratinocytes. A direct comparison was made with E-cadherin, a well-characterized mechanosensor. Exposure of oral and skin keratinocytes to equiaxial cyclic strain promoted changes in the expression and localization of junction assembly proteins. The knockdown of Dsg3 by siRNA blocked strain-induced junctional remodeling of E-cadherin and Myosin IIa. Importantly, the study demonstrated that Dsg3 regulates the expression and localization of yes-associated protein (YAP), a mechanosensory, and an effector of the Hippo pathway. Furthermore, we showed that Dsg3 formed a complex with phospho-YAP and sequestered it to the plasma membrane, while Dsg3 depletion had an impact on both YAP and phospho-YAP in their response to mechanical forces, increasing the sensitivity of keratinocytes to the strain or substrate rigidity-induced nuclear relocation of YAP and phospho-YAP. Plakophilin 1 (PKP1) seemed to be crucial in recruiting the complex containing Dsg3/phospho-YAP to the cell surface since its silencing affected Dsg3 junctional assembly with concomitant loss of phospho-YAP at the cell periphery. Finally, we demonstrated that this Dsg3/YAP pathway has an influence on the expression of YAP1 target genes and cell proliferation. Together, these findings provide evidence of a novel role for Dsg3 in keratinocyte mechanotransduction.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Desmogleína 3/metabolismo , Desmossomos/metabolismo , Queratinócitos/citologia , Fatores de Transcrição/metabolismo , Antígenos CD/metabolismo , Caderinas/metabolismo , Linhagem Celular , Membrana Celular/metabolismo , Proliferação de Células , Desmogleína 3/genética , Técnicas de Silenciamento de Genes , Humanos , Queratinócitos/metabolismo , Mecanotransdução Celular , Miosina não Muscular Tipo IIA/metabolismo , Fosforilação , Transdução de Sinais , Proteínas de Sinalização YAPRESUMO
BACKGROUND: Oral submucous fibrosis (OSMF) is a pre-malignant condition that is strongly associated with the areca nut alkaloids, arecoline (ARC) and arecaidine (ARD). The condition is characterised by the presence of senescent fibroblasts in the subepithelial mesenchyme which have the potential to promote malignancy in the neighbouring epithelial cells. We tested the hypothesis that areca nut alkaloids induce senescence in oral fibroblasts and promote the secretion of invasion-promoting transforming growth factor ß (TGF-ß) and matrix metalloproteinase-2 (MMP-2). METHODS: Two oral fibroblast lines were treated for 48h with ARC and ARD. Senescence-associated ß-galactosidase (SA-ßGal) activity, Ki67 (cycling cells), large 53BP1 foci (irreparable DNA strand breaks) and p16(INK) (4A) (late senescence) were used as markers of cellular senescence and were quantified using indirect immunofluorescence and the ImageJ program. TGF-ß and MMP-2 levels were measured using ELISA. Statistical analyses were performed with the two-tailed unpaired t-test where n = 3 and the Wilcoxon-Mann-Whitney test where n = 6. RESULTS: ARC (100 and 300 µM) and ARD (30 and 100 µM) significantly (P < 0.05) induced fibroblast senescence, as determined by the increased expression of SA-ßGal, 53BP1 staining and CDKN2A/p16(INK) (4A) ; there was also a non-significant reduction in Ki67 staining. Treated cells also showed a three- fivefold increase in TGF-ß and a small non-significant increase in MMP-2. CONCLUSIONS: Areca nut alkaloids induce senescence in oral fibroblasts and promote increased secretion of TGF-ß and perhaps MMP-2 that may create a tissue environment thought to be critical in the progression of OSMF to malignancy.
Assuntos
Areca/química , Arecolina/análogos & derivados , Arecolina/toxicidade , Dano ao DNA , Fibroblastos/efeitos dos fármacos , Neoplasias Bucais/induzido quimicamente , Fibrose Oral Submucosa/induzido quimicamente , Ciclo Celular/efeitos dos fármacos , Linhagem Celular , Senescência Celular/efeitos dos fármacos , Progressão da Doença , Humanos , Metaloproteinase 2 da Matriz/metabolismo , Neoplasias Bucais/metabolismo , Neoplasias Bucais/patologia , Fibrose Oral Submucosa/metabolismo , Fibrose Oral Submucosa/patologia , Fator de Crescimento Transformador beta/metabolismo , Proteína 1 de Ligação à Proteína Supressora de Tumor p53/metabolismo , beta-Galactosidase/metabolismoRESUMO
The Hippo-YAP pathway serves as a central signalling hub in epithelial tissue generation and homeostasis. Yes-associated protein (YAP) is an essential downstream transcription cofactor of this pathway, with its activity being negatively regulated by Hippo kinase-mediated phosphorylation, leading to its cytoplasmic translocation or degradation. Our recent study showed phospho-YAP complexes with Desmoglein-3 (Dsg3), the desmosomal cadherin known to be required for junction assembly and cell-cell adhesion. In this study, we show that YAP inhibition by Verteporfin (VP) caused a significant downregulation of desmosomal genes and a remarkable reduction in desmosomal proteins, including the Dsg3/phospho-YAP complex, resulting in attenuation of cell cohesion. We also found the desmosomal genes, along with E-cadherin, were the YAP-TEAD transcriptional targets and Dsg3 regulated key Hippo components, including WWTR1/TAZ, LATS2 and the key desmosomal molecules. Furthermore, Dsg3 and phospho-YAP exhibited coordinated regulation in response to varied cell densities and culture durations. Overexpression of Dsg3 could compensate for VP mediated loss of adhesion components and proper architecture of cell junctions. Thus, our findings suggest that Dsg3 plays a crucial role in the Hippo network and regulates junction configuration via complexing with phospho-YAP.
RESUMO
Propionic Acidemia (PA) is a rare metabolic disorder caused by the defect in enzyme (propionyl-coenzyme A (CoA) carboxylase) leading to the abnormal accumulation of metabolites of branched-chain amino acid catabolism in blood and urine. We describe the first ever diagnosed case in our setup of early onset PA in a 06 months old baby girl who presented with the complaints of decreased feed intake, lethargy, vomiting, failure to thrive, and intermittent seizures. The basic laboratory investigations showed pancytopenia along with high anion gap metabolic acidosis, urine dipstick positive for ketones, and hyperammonemia. Plasma amino acid analysis by ion exchange chromatography (IEC) showed elevated plasma glycine and lysine levels. Finally, urine organic acid analysis by gas chromatography-mass spectrometry (GCMS) showed marked elevation of 3-hydroxy propionate, methyl citrate, and 3-hydroxy, 2 methylbutyric acid with moderate rise in 3-hydroxy butyric acid without an elevation of methylmalonate in urine, thus giving the diagnosis of PA. Key Words: Propionic acidemia, Propionyl-CoA Carboxylase deficiency, Gas chromatography-mass spectrometry.
Assuntos
Acidemia Propiônica , Aminoácidos de Cadeia Ramificada , Ácido Butírico , Citratos , Coenzima A , Feminino , Glicina , Humanos , Lactente , Cetonas , Lisina , Metilmalonil-CoA Descarboxilase , Propionatos/metabolismo , Acidemia Propiônica/diagnósticoRESUMO
Background: The incidence of maternal mortality and morbidity related to the termination of unwanted pregnancy in Pakistan is rising at an alarming rate. Instant Postpartum insertion of intrauterine contraceptive device (PPIUCD) is an effective contraceptive measure to reduce unexpected pregnancy and its associated complications in developing countries like Pakistan. Methods: The current study was conducted in a public sector hospital in Karachi with a total of 7314 pregnant women counselled for insertion of PPIUCD antenatally. Out of which 5682 women agreed to the insertion and 1632 refused the procedure, mostly due to unfamiliarity with PPIUCD insertion. PPIUCD was inserted within 48 hours of delivery in 1441 patients and they were followed for 6 months onwards. Results: Total postpartum insertions were 1441 which was found to be an effective measure with the continuation rate of 91% among 785 followed up cases. Postpartum IUCD insertion was found as an effective, satisfactory and convenient practice for the women of developing countries like Pakistan, to get an on-time appropriate contraceptive measure. Conclusion: : PPIUCD was found to have high retention and low expulsion rate and its efficacy can be improved further by proper training and skills of healthcare professionals. In this regard, appropriate strategies should be formulated and implemented at the statutory level by increasing social awareness and practice of using PPIUCD by health care providers to reduce undesired pregnancies.
Assuntos
Dispositivos Intrauterinos , Feminino , Humanos , Gravidez , Anticoncepção , Período Pós-Parto , Anticoncepcionais , Pessoal de SaúdeRESUMO
The immunobullous condition Pemphigus Vulgaris (PV) is caused by autoantibodies targeting the adhesion proteins of desmosomes, leading to blistering in the skin and mucosal membrane. There is still no cure to the disease apart from the use of corticosteroids and immunosuppressive agents. Despite numerous investigations, the pathological mechanisms of PV are still incompletely understood, though the etiology is thought to be multifactorial. Thus, further understanding of the molecular basis underlying this disease process is vital to develop targeted therapies. Ample studies have highlighted the role of Desmoglein-3 (DSG3) in the initiation of disease as DSG3 serves as a primary target of PV autoantibodies. DSG3 is a pivotal player in mediating outside-in signaling involved in cell junction remodeling, cell proliferation, differentiation, migration or apoptosis, thus validating its biological function in tissue integrity and homeostasis beyond desmosome adhesion. Recent studies have uncovered new activities of DSG3 in regulating p53 and the yes-associated protein (YAP), with the evidence of dysregulation of these pathways demonstrated in PV. The purpose of this review is to summarize the earlier and recent advances highlighting our recent findings related to PV pathogenesis that may pave the way for future research to develop novel specific therapies in curing this disease.
RESUMO
Pemphigus Vulgaris (PV) is a life-threatening autoimmune disease manifested with blisters in the skin and mucosa and caused by autoantibodies against adhesion protein desmoglein-3 (Dsg3) expressed in epithelial membrane linings of these tissues. Despite many studies, the pathogenesis of PV remains incompletely understood. Recently we have shown Dsg3 plays a role in regulating the yes-associated protein (YAP), a co-transcription factor and mechanical sensor, and constraining reactive oxygen species (ROS). This study investigated the effect of PV sera as well as the anti-Dsg3 antibody AK23 on these molecules. We detected elevated YAP steady-state protein levels in PV cells surrounding blisters and perilesional regions and in keratinocytes treated with PV sera and AK23 with concomitant transient ROS overproduction. Cells treated with hydrogen peroxide also exhibited augmented nuclear YAP accompanied by reduction of Dsg3 and α-catenin, a negative regulator of YAP. As expected, transfection of α-catenin-GFP plasmid rendered YAP export from the nucleus evoked by hydrogen peroxide. In addition, suppression of total YAP was observed in hydrogen peroxide treated cells exposed to antioxidants with enhanced cell-cell adhesion being confirmed by decreased fragmentation in the dispase assay compared to hydrogen peroxide treatment alone. On the other hand, the expression of exogenous YAP disrupted intercellular junction assembly. In contrast, YAP depletion resulted in an inverse effect with augmented expression of junction assembly proteins, including Dsg3 and α-catenin capable of abolishing the effect of AK23 on Dsg3 expression. Finally, inhibition of other kinase pathways, including p38MAPK, also demonstrated suppression of YAP induced by hydrogen peroxide. Furthermore, antioxidant treatment of keratinocytes suppressed PV sera-induced total YAP accumulation. In conclusion, this study suggests that oxidative stress coupled with YAP dysregulation attributes to PV blistering, implying antioxidants may be beneficial in the treatment of PV.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Autoanticorpos/metabolismo , Estresse Oxidativo/imunologia , Pênfigo/imunologia , Fatores de Transcrição/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Autoanticorpos/sangue , Autoanticorpos/imunologia , Estudos de Casos e Controles , Adesão Celular/efeitos dos fármacos , Adesão Celular/imunologia , Linhagem Celular , Desmogleína 3/imunologia , Desmogleína 3/metabolismo , Técnicas de Silenciamento de Genes , Voluntários Saudáveis , Humanos , Queratinócitos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/imunologia , Mucosa Bucal/imunologia , Mucosa Bucal/patologia , Estresse Oxidativo/efeitos dos fármacos , Pênfigo/sangue , Pênfigo/tratamento farmacológico , Pênfigo/patologia , Espécies Reativas de Oxigênio/metabolismo , Fatores de Transcrição/genética , Proteínas de Sinalização YAP , alfa Catenina/metabolismoRESUMO
Kidney disease prevalence increases with age, with a common feature of the disease being defects in the epithelial tight junctions. Emerging evidence suggests that the desmosomal adhesion protein Desmoglein-3 (Dsg3) functions beyond the desmosomal adhesion and plays a role in regulating the fundamental pathways that govern cell fate decisions in response to environmental chemical and mechanical stresses. In this study, we explored the role of Dsg3 on dome formation, reactive oxygen species (ROS) production and transepithelial electrical resistance (TER) in MDCK cells, a kidney epithelial cell model widely used to study cell differentiation and tight junction formation and integrity. We show that overexpression of Dsg3 constrained nuclear ROS production and cellular doming in confluent cell cultures and these features coincided with augmented TER and enhanced tight junction integrity. Conversely, cells expressing dominant-negative Dsg3ΔC mutants exhibited heightened ROS production and accelerated doming, accompanied by increased apoptosis, as well as cell proliferation, with massive disruption in F-actin organization and accumulation, and alterations in tight junctions. Inhibition of actin polymerization and protein synthesis was able to sufficiently block dome formation in mutant populations. Taken together, these findings underscore that Dsg3 has a role in controlling cellular viability and differentiation as well as the functional integrity of tight junctions in MDCK cells.
Assuntos
Desmogleína 3/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Junções Íntimas/fisiologia , Actinas/metabolismo , Animais , Apoptose/genética , Diferenciação Celular , Proliferação de Células/genética , Citoesqueleto/genética , Desmogleína 3/genética , Cães , Impedância Elétrica , Células Madin Darby de Rim Canino , Mutação/genética , Junções Íntimas/ultraestruturaRESUMO
Desmoglein-3 (Dsg3), the Pemphigus Vulgaris (PV) antigen (PVA), plays an essential role in keratinocyte cell-cell adhesion and regulates various signaling pathways involved in the progression and metastasis of cancer where it is upregulated. We show here that expression of Dsg3 impacts on the expression and function of p53, a key transcription factor governing the responses to cellular stress. Dsg3 depletion increased p53 expression and activity, an effect enhanced by treating cells with UVB, mechanical stress and genotoxic drugs, whilst increased Dsg3 expression resulted in the opposite effects. Such a pathway in the negative regulation of p53 by Dsg3 was Dsg3 specific since neither E-cadherin nor desmoplakin knockdown caused similar effects. Analysis of Dsg3-/- mouse skin also indicated an increase of p53/p21WAF1/CIP1 and cleaved caspase-3 relative to Dsg3+/- controls. Finally, we evaluated whether this pathway was operational in the autoimmune disease PV in which Dsg3 serves as a major antigen involved in blistering pathogenesis. We uncovered increased p53 with diffuse cytoplasmic and/or nuclear staining in the oral mucosa of patients, including cells surrounding blisters and the pre-lesional regions. This finding was verified by in vitro studies where treatment of keratinocytes with PV sera, as well as a characterized pathogenic antibody specifically targeting Dsg3, evoked pronounced p53 expression and activity accompanied by disruption of cell-cell adhesion. Collectively, our findings suggest a novel role for Dsg3 as an anti-stress protein, via suppression of p53 function, and this pathway is disrupted in PV.