RESUMEN
The importance of the microbiome in health and its disruption in disease is continuing to be elucidated. However, the multitude of host and environmental factors that influence the microbiome are still largely unknown. Here, we examined UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferase 3 (Galnt3)-deficient mice, which serve as a model for the disease hyperphosphatemic familial tumoral calcinosis (HFTC). In HFTC, loss of GALNT3 activity in the bone is thought to lead to altered glycosylation of the phosphate-regulating hormone fibroblast growth factor 23 (FGF23), resulting in hyperphosphatemia and subdermal calcified tumors. However, GALNT3 is expressed in other tissues in addition to bone, suggesting that systemic loss could result in other pathologies. Using semiquantitative real-time PCR, we found that Galnt3 is the major O-glycosyltransferase expressed in the secretory cells of salivary glands. Additionally, 16S rRNA gene sequencing revealed that the loss of Galnt3 resulted in changes in the structure, composition, and stability of the oral microbiome. Moreover, we identified the major secreted salivary mucin, Muc10, as an in vivo substrate of Galnt3. Given that mucins and their O-glycans are known to interact with various microbes, our results suggest that loss of Galnt3 decreases glycosylation of Muc10, which alters the composition and stability of the oral microbiome. Considering that oral findings have been documented in HFTC patients, our study suggests that investigating GALNT3-mediated changes in the oral microbiome may be warranted.
Asunto(s)
Calcinosis/metabolismo , Calcinosis/microbiología , Hiperostosis Cortical Congénita/metabolismo , Hiperostosis Cortical Congénita/microbiología , Hiperfosfatemia/metabolismo , Hiperfosfatemia/microbiología , Microbiota/genética , N-Acetilgalactosaminiltransferasas/metabolismo , Glándulas Salivales/metabolismo , Animales , Calcinosis/genética , Femenino , Factor-23 de Crecimiento de Fibroblastos , Glicosilación , Glicosiltransferasas/metabolismo , Hiperostosis Cortical Congénita/genética , Hiperfosfatemia/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Mucinas/química , Mucinas/metabolismo , N-Acetilgalactosaminiltransferasas/genética , Polisacáridos/metabolismo , ARN Ribosómico 16S/genética , Polipéptido N-AcetilgalactosaminiltransferasaRESUMEN
The widely expressed Anoctamin 6 (Ano6) supports different Ca2+ -dependent functions, but little is known about its role in salivary glands. Mouse submandibular gland (SMG) acinar cells exhibited a robust regulatory volume decrease (RVD) following cell swelling that was reduced approximately 70% in Ano6-/- mice. Ca2+ -free conditions nearly eliminated the RVD response suggesting that Ano6 is an obligatory component of the cell volume-activated, Ca2+ -dependent RVD pathway in salivary gland acinar cells. Ex vivo agonist-stimulated secretion of water and ions was unaffected by Ano6 disruption under both isotonic and hypotonic conditions suggesting that Ano6 does not play a major role in fluid and electrolyte secretion. In contrast, the total amount of ß-adrenergic-dependent protein secretion by the SMG was significantly reduced in Ano6-/- mice. Closer inspection of these latter results revealed that protein secretion was affected only in the female SMG by Ano6 disruption. These results indicate that Ano6 modulates the RVD response and protein secretion by salivary gland acinar cells.
Asunto(s)
Células Acinares/metabolismo , Anoctaminas/metabolismo , Tamaño de la Célula , Proteínas de Transferencia de Fosfolípidos/metabolismo , Saliva/metabolismo , Animales , Anoctamina-1/metabolismo , Canales de Cloruro/metabolismo , Cloruros/metabolismo , Ratones Noqueados , Glándulas Salivales , Glándula Submandibular/metabolismoRESUMEN
The nonselective anion exchanger Slc26a6, also known as putative anion transporter 1 and chloride/formate exchanger, is thought to play a major role in HCO3- transport in exocrine glands. In this study, Slc26a6 null mice were used to explore the function of Slc26a6 in the exocrine pancreas. Slc26a6 primarily localized to the apical membrane of pancreatic exocrine acinar cells. The volume of stimulated juice secretion by the ex vivo pancreas was significantly reduced ~35% in Slc26a6-/- mice, but no changes occurred in the gross structure or gland weights of Slc26a6 null mice. The secretion of pancreatic juice by Slc26a6+/+ mice was dependent on HCO3- while, in contrast, fluid secretion by Slc26a6-/- mice was independent of HCO3-, suggesting that Slc26a6 mediates the HCO3--dependent component of fluid secretion. Consistent with these observations, disruption of Slc26a6 also significantly reduced HCO3- secretion by the pancreas ~35%. Taken together, these results demonstrate that the apical Slc26a6 anion exchanger in acinar cells is involved in HCO3--dependent fluid secretion but that another major HCO3--independent pathway is the primary driver of the fluid secretion process in the mouse pancreas.
Asunto(s)
Células Acinares/metabolismo , Antiportadores/genética , Bicarbonatos/metabolismo , Líquidos Corporales/metabolismo , Páncreas Exocrino/metabolismo , Transportadores de Sulfato/genética , Células Acinares/citología , Animales , Anoctamina-1/genética , Anoctamina-1/metabolismo , Antiportadores/deficiencia , Acuaporina 5/genética , Acuaporina 5/metabolismo , Peso Corporal , Línea Celular , Membrana Celular/metabolismo , Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Regulador de Conductancia de Transmembrana de Fibrosis Quística/metabolismo , Femenino , Regulación de la Expresión Génica , Humanos , Transporte Iónico , Masculino , Ratones , Ratones Noqueados , Técnicas de Cultivo de Órganos , Tamaño de los Órganos , Páncreas Exocrino/citología , Miembro 2 de la Familia de Transportadores de Soluto 12/genética , Miembro 2 de la Familia de Transportadores de Soluto 12/metabolismo , Transportadores de Sulfato/deficienciaRESUMEN
The solute carrier family 26 (SLC26) gene family encodes at least 10 different anion exchangers. SLC26 member 6 (SLC26A6 or CFEX/PAT-1) and the cystic fibrosis transmembrane conductance regulator (CFTR) co-localize to the apical membrane of pancreatic duct cells, where they act in concert to drive HCO3- and fluid secretion. In contrast, in the small intestine, SLC26A6 serves as the major pathway for oxalate secretion. However, little is known about the function of Slc26a6 in murine salivary glands. Here, RNA sequencing-based transcriptional profiling and Western blots revealed that Slc26a6 is highly expressed in mouse submandibular and sublingual salivary glands. Slc26a6 localized to the apical membrane of salivary gland acinar cells with no detectable immunostaining in the ducts. CHO-K1 cells transfected with mouse Slc26a6 exchanged Cl- for oxalate and HCO3-, whereas two other anion exchangers known to be expressed in salivary gland acinar cells, Slc4a4 and Slc4a9, mediated little, if any, Cl-/oxalate exchange. Of note, both Cl-/oxalate exchange and Cl-/HCO3- exchange were significantly reduced in acinar cells isolated from the submandibular glands of Slc26a6-/- mice. Oxalate secretion in submandibular saliva also decreased significantly in Slc26a6-/- mice, but HCO3- secretion was unaffected. Taken together, our findings indicate that Slc26a6 is located at the apical membrane of salivary gland acinar cells, where it mediates Cl-/oxalate exchange and plays a critical role in the secretion of oxalate into saliva.
Asunto(s)
Células Acinares/metabolismo , Antiportadores/metabolismo , Membrana Celular/metabolismo , Ácido Oxálico/metabolismo , Glándula Submandibular/metabolismo , Transportadores de Sulfato/metabolismo , Células Acinares/citología , Animales , Antiportadores/genética , Bicarbonatos/metabolismo , Células CHO , Membrana Celular/genética , Antiportadores de Cloruro-Bicarbonato/genética , Antiportadores de Cloruro-Bicarbonato/metabolismo , Cloruros/metabolismo , Cricetulus , Ratones , Ratones Noqueados , Saliva/metabolismo , Simportadores de Sodio-Bicarbonato/genética , Simportadores de Sodio-Bicarbonato/metabolismo , Glándula Submandibular/citología , Transportadores de Sulfato/genéticaRESUMEN
Aging has pronounced effects on mammalian tissues and cells, but the impacts of aging on salivary gland function are relatively unknown. This study aims to evaluate the effects of aging on submandibular gland (SMG) and parotid gland (PG) functions in the male senescence-accelerated mouse. In vivo analysis at the systemic level revealed that salivary secretion induced by pilocarpine, a muscarinic agonist, from the SMG was significantly decreased in aged mice, whereas salivary secretion from the PG was not affected. To evaluate organ-level function, the SMG was perfused with the muscarinic agonists carbachol and calcium ionophore A23187 ex vivo to induce salivary secretion, and decreased saliva production was also observed in the aged SMG. Histological analysis revealed the presence of CD4-positive lymphocytes infiltrating the aged SMG. Furthermore, real-time PCR revealed that the aged SMG exhibited accelerated cell aging, increased levels of the inflammatory cytokine interleukin-6, and decreased mRNA levels of the water channel protein aquaporin-5 (AQP5). In summary, these results demonstrate that SMG function in aged mice was diminished, and that cell senescence, chronic inflammation, and the decreased gene expression of AQP5 are the likely causes of hyposalivation in the SMG of aged mice.
Asunto(s)
Linfocitos T CD4-Positivos/patología , Senescencia Celular/inmunología , Inflamación , Glándula Parótida , Glándula Submandibular , Xerostomía , Animales , Acuaporina 5/análisis , Calcimicina/farmacología , Ionóforos de Calcio/farmacología , Carbacol/farmacología , Agonistas Colinérgicos/farmacología , Regulación hacia Abajo , Inflamación/inmunología , Inflamación/patología , Inflamación/fisiopatología , Interleucina-6/análisis , Masculino , Ratones , Glándula Parótida/efectos de los fármacos , Glándula Parótida/inmunología , Glándula Parótida/patología , Glándula Parótida/fisiopatología , Glándula Submandibular/efectos de los fármacos , Glándula Submandibular/inmunología , Glándula Submandibular/patología , Glándula Submandibular/fisiopatología , Resultado del Tratamiento , Xerostomía/tratamiento farmacológico , Xerostomía/etiología , Xerostomía/inmunologíaRESUMEN
Water-handling epithelia are sensitive to the osmotic environment. In this study, the effects of a hypo-osmotic challenge on carbachol (CCh)-induced fluid secretion was investigated using an ex vivo submandibular gland perfusion technique and intracellular pH and Ca(2+) measurements. The osmolality of the perfusion solution was altered to examine the response of the gland to a hypotonic challenge. The flow rate was increased by 34% with a 30% hypotonic solution (225 mosmol/kgH2O), although the Ca(2+) response was unchanged. The lowering of the external Cl(-) by 50% abolished this increase in the 30% hypotonic solution. Furthermore, bumetanide, an inhibitor of the Na(+)-K(+)-2Cl(-) cotransporter (NKCC1), completely inhibited the fluid secretion increase caused by the 30% hypotonic solution, and both the total amount of fluid and the flow rate were identical to those of the isotonic solution. This finding was confirmed by measuring the NKCC1 bumetanide-dependent NH4 (+) transport; Na(+)-K(+)-2Cl(-) transport was upregulated >40% by a 30% hypotonic challenge. Therefore, the increase in CCh-induced fluid secretion in response to hypotonic conditions can be attributed, to a large extent, to the specific activation of the NKCC1.
Asunto(s)
Líquidos Corporales/metabolismo , Presión Osmótica/fisiología , Miembro 2 de la Familia de Transportadores de Soluto 12/metabolismo , Glándula Submandibular/metabolismo , Animales , Bumetanida/farmacología , Señalización del Calcio/efectos de los fármacos , Señalización del Calcio/fisiología , Carbacol/farmacología , Ratones , Ratones Endogámicos C57BL , Modelos Animales , Concentración Osmolar , Inhibidores del Simportador de Cloruro Sódico y Cloruro Potásico/farmacología , Miembro 2 de la Familia de Transportadores de Soluto 12/efectos de los fármacosRESUMEN
OBJECTIVES: Xerostomia, a common complication of type 2 diabetes, leads to an increased risk of caries, dysphagia, and dysgeusia. Although anti-vascular endothelial growth factor (VEGF) antibodies, such as ranibizumab (RBZ), have been used to treat diabetic retinopathy, their effects on the salivary glands are unknown. This study evaluated the effects of RBZ on salivary glands to reduce inflammation and restore salivary function in a mouse model of type 2 diabetes. METHODS: Male KK-Ay mice with type 2 diabetes (10-12 weeks old) were used. The diabetes mellitus (DM) group received phosphate-buffered saline, while the DM + RBZ group received an intraperitoneal administration of RBZ (100 µg/kg) 24 h before the experiment. RESULTS: Ex vivo perfusion experiments showed a substantial increase in salivary secretion from the submandibular gland (SMG) in the DM + RBZ group. In addition, the mRNA expression levels of TNF-α and IL-1ß were considerably lower in this group. In contrast, those of aquaporin 5 were substantially higher in the DM + RBZ group, as revealed by quantitative reverse transcription PCR. Furthermore, the number of lymphocyte infiltration spots in the SMG was notably lower in the DM + RBZ group. Finally, intracellular Ca2+ signaling in acinar cells was considerably higher in the DM + RBZ group than that in the DM group. CONCLUSION: Treating a type 2 diabetic mouse model with RBZ restored salivary secretion through its anti-inflammatory effects.
Asunto(s)
Diabetes Mellitus Tipo 2 , Saliva , Factor A de Crecimiento Endotelial Vascular , Animales , Masculino , Ratones , Acuaporina 5/metabolismo , Acuaporina 5/genética , Diabetes Mellitus Experimental/tratamiento farmacológico , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Modelos Animales de Enfermedad , Interleucina-1beta/metabolismo , Interleucina-1beta/genética , Ranibizumab/farmacología , Ranibizumab/administración & dosificación , Ranibizumab/uso terapéutico , Saliva/metabolismo , Glándula Submandibular/efectos de los fármacos , Glándula Submandibular/metabolismo , Glándula Submandibular/patología , Factor de Necrosis Tumoral alfa/metabolismo , Factor de Necrosis Tumoral alfa/genética , Factor A de Crecimiento Endotelial Vascular/metabolismo , Factor A de Crecimiento Endotelial Vascular/genética , Xerostomía/tratamiento farmacológico , Xerostomía/etiologíaRESUMEN
PURPOSE: This study aimed to evaluate the potential of Endothelin-1 (ET-1), a peptide derived from vascular endothelial cells, as a biomarker for diagnosing peri-implant diseases. METHODS: A cohort of 29 patients with a total of 76 implants was included in this study and subsequently divided into three groups based on peri-implant clinical parameters and radiographic examination: healthy (peri-implant health) (n = 29), mucositis (n = 22), and peri-implantitis (n = 25) groups. The levels of ET-1 (ρg/site) and interleukin (IL)-1ß (ρg/site) in peri-implant sulcus fluid (PISF) samples were determined using enzyme immunoassay. Statistical analyses were conducted using Kruskal-Wallis and Steel-Dwass tests. Logistic regression and receiver operating characteristic (ROC) curve analyses were performed to evaluate the diagnostic performance of the biomarkers. RESULTS: ET-1 levels were significantly elevated in the peri-implantitis group compared to those in the healthy group, and were highest in the peri-implant mucositis group. Additionally, IL-1ß levels were significantly higher in the peri-implantitis group than those in the healthy group. ROC curve analysis indicated that ET-1 exhibited superior area under the curve values, sensitivity, and specificity compared to those of IL-1ß. CONCLUSIONS: Our findings suggest that the presence of ET-1 in PISF plays a role in peri-implant diseases. Its significantly increased expression in peri-implant mucositis indicates its potential for enabling earlier and more accurate assessments of peri-implant inflammation when combined with conventional examination methods.
Asunto(s)
Biomarcadores , Endotelina-1 , Interleucina-1beta , Periimplantitis , Humanos , Endotelina-1/metabolismo , Endotelina-1/análisis , Periimplantitis/diagnóstico , Periimplantitis/metabolismo , Estudios Transversales , Masculino , Femenino , Biomarcadores/metabolismo , Biomarcadores/análisis , Persona de Mediana Edad , Interleucina-1beta/metabolismo , Interleucina-1beta/análisis , Implantes Dentales/efectos adversos , Adulto , Mucositis/diagnóstico , Mucositis/metabolismo , Líquido del Surco Gingival/química , Líquido del Surco Gingival/metabolismo , Anciano , Curva ROCRESUMEN
PURPOSE: This study aimed to investigate the effects of chronic kidney disease (CKD) on the structural and mechanical properties of the maxillary and mandibular cortical bone. METHODS: The maxillary and mandibular cortical bones from CKD model rats were used in this study. CKD-induced histological, structural, and micro-mechanical alterations were assessed using histological analyses, micro-computed tomography (CT), bone mineral density (BMD) measurements, and nanoindentation tests. RESULTS: Histological analyses indicated that CKD caused an increase in the number of osteoclasts and a decrease in the number of osteocytes in the maxilla. Micro-CT analysis revealed that CKD induced a void volume/cortical volume (%) increase, which was more remarkable in the maxilla than in the mandible. CKD also significantly decreased the BMD in the maxilla. In the nanoindentation stress-strain curve, the elastic-plastic transition point and loss modulus were lower in the CKD group than that in the control group in the maxilla, suggesting that CKD increased micro fragility of the maxillary bone. CONCLUSIONS: CKD affected bone turnover in the maxillary cortical bone. Furthermore, the maxillary histological and structural properties were compromised, and micro-mechanical properties, including the elastic-plastic transition point and loss modulus, were altered by CKD.
Asunto(s)
Maxilar , Insuficiencia Renal Crónica , Ratas , Animales , Maxilar/diagnóstico por imagen , Maxilar/patología , Microtomografía por Rayos X , Insuficiencia Renal Crónica/patología , Densidad Ósea , Hueso Cortical/diagnóstico por imagen , Hueso Cortical/patologíaRESUMEN
PURPOSE: The present study was performed to examine the mandibular deformation during mouth opening in edentulous patients, treated with an implant-supported fixed prosthesis using strain gauges, and identify factors affecting deformation. METHODS: Twenty patients with a fully edentulous mandible who received either 4 or ≥6 implants were included. The distal-most implants were placed mesial to the mental foramen (premolar region) in patients with 4 implants and distal to the mental foramen (molar region) in patients with ≥6 implants. Mandibular deformation during mouth opening was measured using strain gauges in two directions: anteroposterior direction and lateral direction between the distal-most implants on the left and right sides (arch width). The mandibular anatomy was evaluated using computed tomography. RESULTS: Arch width reduction between the left and right implants during mouth opening ranged from 47.38 to 512.80 µm; the range of deformation was 0.12 to 15.14 µm in the anteroposterior direction. Furthermore, a significant positive correlation was noted between arch width reduction in the premolar region and the ratio between the symphyseal bone height and width (P = 0.0003, r = 0.72). CONCLUSION: The reduction in arch width was higher in the molar region than in the premolar region during mouth opening. Moreover, the reduction could be high in the mandibular symphyseal bone because of its greater height and lesser width. The ratio between the symphyseal bone height and width is defined as the mandibular deformation index (MDI) and is used to predict the rate of mandibular bone deformation.
Asunto(s)
Implantes Dentales , Arcada Edéntula , Boca Edéntula , Implantación Dental Endoósea/métodos , Implantes Dentales/efectos adversos , Prótesis Dental de Soporte Implantado/efectos adversos , Humanos , Arcada Edéntula/cirugía , Mandíbula/cirugíaRESUMEN
PURPOSE: The purpose of this study was to investigate serum undercarboxylated osteocalcin (ucOC) levels in partially edentulous patients scheduled to receive implant treatment and determine the association between ucOC levels, vegetable intake, vitamin K, dietary fiber intake, and functional tooth number in the posterior region (p-FTN). METHODS: A total of 46 patients (20 male and 26 female, 61.9 ± 12.7 years old) were included. The association among serum ucOC levels, vegetable intake, vitamin K and dietary fiber intake was assessed using Spearman's rank correlation coefficient and binary logistic regression analysis. RESULTS: In total, 35% of patients (16/46 subjects) showed an abnormally high ucOC level (⧠4.5 ng/mL). p-FTN showed a weak positive correlation with vegetable intake, vitamin K and dietary fiber intake (r = 0.28, 0.21, and 0.14, respectively) and a significant negative correlation with ucOC levels (r = - 0.51). Multivariate analysis demonstrated that p-FTN as well as vitamin K intake showed a significant negative association with serum ucOC levels. CONCLUSIONS: More than one-third of patients showed abnormally high ucOC levels. p-FTN showed a negative association with serum ucOC levels, which indicated the possibility that oral status affected bone quality.
Asunto(s)
Estado Nutricional , Vitamina K , Humanos , Masculino , Femenino , Persona de Mediana Edad , Anciano , Osteocalcina , Huesos , Fibras de la DietaRESUMEN
The loss of bone quantity and quality in postmenopausal female patients can be a problem for dental treatment. A sufficient intake of nutrients such as calcium, magnesium, and vitamins D and K is likely correlated with the mechanical properties of bone. In particular, vitamin K2, also called menaquinone (MK), inhibits bone loss in postmenopausal women. Here we demonstrate the microstructural and mechanical properties of bone recovery in ovariectomized (OVX) rats during MK-7 administration. Bilateral ovariectomy and a sham operation were performed on 14-week-old female SPF Wistar rats. MK-4 and -7 were orally administered at 30 mg/kg daily for 12 weeks. The femur was used for the 3-point bending test and microstructural analysis of the cancellous bone by micro-CT, and the mandibular cortical bone for the evaluation of mechanical properties on a nanoscale. Micro-computed tomography revealed irregular trabecular architecture, hollow marrow cavities, and sparse trabecular bone in the femurs of the OVX group. Trabecular bone structure analysis showed that the MK-7 group had greater bone volume per tissue volume (BV/TV) and a higher trabecular number than the OVX group. The bulk-scale 3-point bending test did not allow the mechanical properties between OVX and OVX/MK7 groups to be discerned, yet at the smallest level, the elastic-plastic transition point of the nanoindentation stress-strain curve of the mandibular cortical bone was higher in the MK-7 group than in the OVX group. These findings suggest that MK-7 enables bone microstructural and mechanical recovery in the OVX model.
Asunto(s)
Densidad Ósea , Animales , Femenino , Humanos , Ovariectomía , Ratas , Ratas Wistar , Vitamina K 2/análogos & derivados , Vitamina K 2/farmacología , Microtomografía por Rayos XRESUMEN
PURPOSE: In this study, we aimed to investigate the effect of glucose metabolism on bone healing after tooth extraction in an osteoporosis rat model administered zoledronic acid (ZA) and dexamethasone (DX). METHODS: In total, 24 male Wistar rats (4 weeks old) were randomly assigned to four groups: Control (subcutaneous physiological saline), ZD (subcutaneous ZA and DX twice a week), Ins+ZD (subcutaneous insulin followed by ZD treatment), and Met+ZD (oral metformin followed by ZD treatment). Blood was collected every two weeks . Two weeks after treatment initiation, the first molar tooth on the right maxilla was extracted from all rats. Four weeks later, the rats were sacrificed, and bone healing was assessed. Maxillae samples were fixed and scanned using micro-computed tomography for quantifying areas of bone defects. Hematoxylin-eosin and tartrate-resistant acid phosphatase (TRAP) staining were performed to evaluate bone apoptosis and osteoclast number. RESULTS: In all experimental groups, body weight was statistically lower than that in the Control group, with no changes observed in uncarboxylated osteocalcin concentrations. The radiological analysis revealed that insulin or metformin administration improved healing in the tooth extraction socket (p < 0.01). Histological examination revealed that the osteonecrosis area was reduced in the Ins+ZD and Met+ZD groups (p < 0.01). TRAP staining presented increased osteoclast numbers in the ZD group when compared with that observed in the Control. CONCLUSIONS: Tooth extraction with long-term ZA and DX administration inhibited bone remodeling and induced bisphosphonate-related osteonecrosis of the jaw-like lesions. Metformin exerted protective effects ag ainst osteonecrosis of the jaw.
Asunto(s)
Osteonecrosis de los Maxilares Asociada a Difosfonatos , Conservadores de la Densidad Ósea , Metformina , Animales , Osteonecrosis de los Maxilares Asociada a Difosfonatos/etiología , Osteonecrosis de los Maxilares Asociada a Difosfonatos/prevención & control , Difosfonatos , Imidazoles , Masculino , Ratas , Ratas Wistar , Extracción Dental , Microtomografía por Rayos XRESUMEN
Reconstruction of a critical-sized osseous defect is challenging in maxillofacial surgery. Despite novel treatments and advances in supportive therapies, severe complications including infection, nonunion, and malunion can still occur. Here, we aimed to assess the use of a beta-tricalcium phosphate (ß-TCP) scaffold loaded with high mobility group box-1 protein (HMGB-1) as a novel critical-sized bone defect treatment in rabbits. The study was performed on 15 specific pathogen-free New Zealand rabbits divided into three groups: Group A had an osseous defect filled with a ß-TCP scaffold loaded with phosphate-buffered saline (PBS) (100 µL/scaffold), the defect in group B was filled with recombinant human bone morphogenetic protein 2 (rhBMP-2) (10 µg/100 µL), and the defect in group C was loaded with HMGB-1 (10 µg/100 µL). Micro-computed tomography (CT) examination demonstrated that group C (HMGB-1) showed the highest new bone volume ratio, with a mean value of 66.5%, followed by the group B (rhBMP-2) (31.0%), and group A (Control) (7.1%). Histological examination of the HMGB-1 treated group showed a vast area covered by lamellar and woven bone surrounding the ß-TCP granule remnants. These results suggest that HMGB-1 could be an effective alternative molecule for bone regeneration in critical-sized mandibular bone defects.
Asunto(s)
Regeneración Ósea/efectos de los fármacos , Proteína HMGB1/farmacología , Mandíbula/metabolismo , Traumatismos Mandibulares/tratamiento farmacológico , Animales , Fosfatos de Calcio/farmacología , Humanos , Masculino , Mandíbula/patología , Traumatismos Mandibulares/mortalidad , Traumatismos Mandibulares/patología , ConejosRESUMEN
Corticosteroids are used in the treatment of many diseases; however, they also induce various side effects. Dexamethasone is one of the most potent corticosteroids, and it has been reported to induce the side effect of impaired salivary gland function. This study aimed to evaluate the effects of dexamethasone on mouse submandibular gland function to gain insight into the mechanism of dexamethasone-induced salivary hypofunction. The muscarinic agonist carbachol (CCh) induced salivary secretion and was not affected by short-term dexamethasone treatment but was decreased following long-term dexamethasone administration. The expression levels of the membrane proteins Na+-K+-2Cl- cotransporter, transmembrane member 16A, and aquaporin 5 were comparable between the control and long-term dexamethasone treatment groups. The CCh-induced increase in calcium concentration was significantly lower in the presence of extracellular Ca2+ in the long-term dexamethasone treatment group compared to that in the control group. Furthermore, CCh-induced salivation in the absence of extracellular Ca2+ and Ca2+ ionophore A23187-induced salivation was comparable between the control and long-term dexamethasone treatment groups. Moreover, salivation induced by the Ca2+-ATPase inhibitor thapsigargin was diminished in the long-term dexamethasone treatment group. In summary, these results demonstrate that short-term dexamethasone treatment did not impair salivary gland function, whereas long-term dexamethasone treatment diminished store-operated Ca2+ entry, resulting in hyposalivation in mouse submandibular glands.
Asunto(s)
Células Acinares/metabolismo , Señalización del Calcio/efectos de los fármacos , Calcio/metabolismo , Carbacol/farmacología , Dexametasona/uso terapéutico , Agonistas Muscarínicos/farmacología , Saliva/metabolismo , Salivación/efectos de los fármacos , Glándula Submandibular/efectos de los fármacos , Células Acinares/efectos de los fármacos , Animales , Ratones , Glándula Submandibular/metabolismoRESUMEN
BACKGROUND: Hypofunction of different organs in the body is associated with diabetes, including in the oral cavity. Diabetes is often associated with xerostomia, but the underlying mechanism is not well characterized. Thus, the mechanisms underlying diabetes-induced xerostomia were investigated in this study in KK-A y mice as an experimental model of type 2 diabetes. METHODS: The mechanisms involved in diabetes-induced xerostomia were investigated using the ex vivo glandular perfusion technique, histological analysis, and immunohistochemical and intracellular signaling analyses. RESULTS: Ex vivo submandibular gland secretions from KK-Ay mice decreased by 30% following stimulation with 0.3 µmol/L carbachol (CCh), a cholinergic agonist. Acinar cell weight was comparable between KK-Ay and control mice, whereas duct cell weight was significantly greater in KK-Ay mice. Concentrations of Na+ and Cl- in the secreted saliva decreased significantly in KK-Ay mice, supporting the finding of increased ductal tissue in KK-Ay mice. Immunohistochemistry revealed no significant differences between KK-Ay and control mice in terms of the expression of Cl- and water channels, Na+ -K+ -2Cl- cotransporters, and membrane proteins critical for fluid secretion. Cellular signaling analysis revealed that the increase in [Ca2+ ]i in response to 0.3 µmol/L CCh was reduced by 30% in KK-Ay mice, although there was no significant difference in the thapsigargin (1.0 µmol/L)-induced increase in store-depleted calcium between KK-Ay and control mice. CONCLUSIONS: These results demonstrate that submandibular fluid secretion is diminished in KK-Ay mice because of a diminished increase in [Ca2+ ]i . Duct cell weight increased in KK-Ay mice, possibly leading to increased ion reabsorption and thus decreased Na+ and Cl- concentrations in the secreted saliva.