Statherin and alpha-amylase levels in saliva from patients with gingivitis and periodontitis.

OBJECTIVES: Salivary statherin and alpha-amylase play significant roles in biofilm formation and pathogenic bacteria adhesion. Examination of these proteins may provide information on their roles in periodontal diseases. The present study was based on the hypothesis that; the salivary proteins -statherin and alpha-amylase- effective on biofilm formation, may play important roles in the etiology of periodontal disease. Therefore, we aimed to analyze the differences in periodontal diseases compared to periodontal health in order to search their roles in periodontal disease. METHODS: Patients with gingivitis (n = 26) and periodontitis (n = 20), and periodontally healthy individuals (n = 21) were included in this study. Unstimulated whole saliva samples were obtained from a total of 67 individuals. Salivary statherin level and alpha-amylase activity were determined using ELISA and enzymatic methods, respectively. RESULTS: Statherin levels in saliva were significantly higher in the periodontitis group compared to the gingivitis group (p = 0.014), while alpha-amylase activities and total protein levels were slightly higher in the periodontitis and gingivitis groups compared to controls, without significant differences among the groups (p = 0.295 and p = 0.019, respectively). Statherin levels showed positive correlations with gingival and plaque indices in the disease groups. CONCLUSIONS: The results suggest that statherin level in saliva increase to provide a protective effect against periodontitis, and higher salivary statherin level is related to the degree of gingival inflammation and plaque accumulation.

In vitro comparison of nanofibrillar and macroporous-spongious composite tissue scaffolds for periodontal tissue engineering.

PURPOSE/AIM OF THE STUDY: The ultimate goal of periodontal treatment is to regenerate the lost periodontal tissues. The interest in nanomaterials in dentistry is growing rapidly and has focused on improvements in various biomedical applications, such as periodontal regeneration and periodontal tissue engineering. To enhance periodontal tissue regeneration, hydroxyapatite (HA) was used in conjunction with other scaffold materials, such as Poly lactic-co-glycolic-acid (PLGA) and collagen (C). The main target of this study was to compare the effects of nano and macrostructures of the tissue scaffolds on cell behavior in vitro for periodontal tissue engineering. MATERIALS AND METHODS: Nanofibrillar and macroporous-spongious composite tissue scaffolds were produced using PLGA/C/HA. Subgroups with BMP-2 signal molecule and without HA were also created. The scaffolds were characterized by FTIR, SEM/EDX techniques, and mechanical tests. The scaffolds were compared in the periodontal ligament (PDL) and MCT3-E1 cell cultures. The cell behaviors; adhesions by SEM, proliferation by WST-1, differentiation by ALP and mineralization with Alizarin Red Tests were determined. RESULTS: Cell adhesion and mineralization were higher in the nanofibrillar scaffolds compared to the macroporous-spongious scaffolds. Macroporous-spongious scaffolds seemed better for the proliferation of PDL cells and differentiation of MC3T3-E1-preosteoblastic cells, while nanofibrillar scaffolds were more convenient for the differentiation of PDL cells and proliferation of MC3T3-E1-preosteoblastic cells. CONCLUSIONS: In general, nanofibrillar scaffolds showed more favorable results in cell behaviors, compared to the macroporous-spongious scaffolds, and mostly, BMP-2 and HA promoted the activities of the cells.

Hippo Signaling: A Stress Response Pathway in Stem Cells.

The Hippo pathway, with its core components and the downstream transcriptional coactivators, controls the self-renewable capacity and stemness features of stem cells and serves as a stress response pathway by regulating proliferation, differentiation and apoptosis. The Hippo pathway interaction with other signaling pathways plays an important role in response to various stress stimuli arising from energy metabolism, hypoxia, reactive oxygen species, and mechanical forces. Depending on the energy levels, the Hippo pathway is regulated by AMP-activated protein kinase (AMPK) and mechanistic target of rapamycin (mTOR), which in turn determines stem cell proliferation (cell survival and growth) and differentiation. Oxidative stress-driven by ROS production also affects the Hippo pathway with transcriptional changes through MST/YAP/FoxO pathway and leads to the activation of pro-apoptotic genes and eventually cell death. HIF1alpha/YAP signaling is critical for the long-term maintenance of mesenchymal stem cells (MSCs) under hypoxia. In this review, we present an overview of stem cell response to stress, including mechanical, hypoxia, metabolic and oxidative stress through the modulation of the Hippo pathway. The biological effects such as autophagy, apoptosis and senescence were discussed in the context of the Hippo pathway in stem cells.

The effect of melatonin on Hippo signaling pathway in dental pulp stem cells.

Dental pulp stem cells (DPSCs) have a high capacity to differentiate into the neuronal cell lineage. Meanwhile, both Hippo signaling and melatonin are key regulators in neuronal differentiation of neuronal progenitor cells. Recently emerging evidences suggest the possible interaction between melatonin and Hippo signaling in different cell lines. But underlying mechanisms involved in the initiation or progression of neurogenic differentiation in DPSCs through this connection need to be explored. Therefore, the scope of this study is to investigate the effect of melatonin on Hippo signaling pathway through the expression of its downstream effector (YAP/p-YAPY357) after the neuronal differentiation of DPSCs. In regard with this, DPSCs were incubated with growth and dopaminergic neuronal differentiation medium with or without melatonin (10 µM) for 21 days. The morphological changes were followed by phase contrast microscopy and differentiation of DPSCs was evaluated by immunofluorescence labelling with NeuN, GFAP, and tyrosine hydroxylase. Furthermore, we evaluated the presence of neural progenitor cells by nestin immunoreactivity. Hippo signaling pathway was investigated by evaluating the immunoreactivity of YAP and p-YAPY357. Our results were also supported by western-blot analysis and SOX2, PCNA and caspase-3 were also evaluated. The positive immunoreactivity for NeuN, tyrosine hydroxylase and negative immunoreactivity for GFAP showed the successful differentiation of DPSCs to neurons, not glial cells. Melatonin addition to dopaminergic media induced tyrosine hydroxylase and decreased significantly nestin expression. The expressions of PCNA and caspase-3 were also decreased significantly with melatonin addition into growth media. Melatonin treatment induced phosphorylation of YAPY357 and reduced YAP expression. In conclusion, melatonin has potential to induce neuronal differentiation and reduce the proliferation of DPSCs by increasing phosphorylation of YAPY357 and eliminating the activity of YAP, which indicates the active state of Hippo signaling pathway.

Glutathione detection in human serum using gold nanoparticle decorated, monodisperse porous silica microspheres in the magnetic form.

A nanozyme for glutathione (GSH) detection in a broad concentration range was synthesized. GSH is usually detected up to an upper limit of 100 µM using current noble metal nanozymes due to the sharp decrease in the colorimetric response with the increasing GSH concentration. Strong inhibition of colorimetric reactions by GSH adsorbed onto noble metal based nanozymes in the form of non-porous, nanoscale particulate materials dispersed in an aqueous medium is the reason for the sharp decrease in the colorimetric response. In the present study, a new magnetic nanozyme synthesized by immobilization of Au nanoparticles (Au NPs) on magnetic, monodisperse porous silica microspheres (>5 µm) obtained by a "staged-shape templating sol-gel protocol" exhibited peroxidase-like activity up to a GSH concentration of 5000 µM. A more controlled linear decrease in the peroxidase-like activity with a lower slope with respect to that of similar nanozymes was observed with the increasing GSH concentration. The proposed design allowed the GSH detection in a broader concentration range depending on the adsorption of GSH onto the Au NPs immobilized on magnetic, monodisperse porous silica microspheres. A calibration plot allowing the detection of GSH in a broad concentration range up to 3300 µM was obtained using the magnetic nanozyme. The GSH concentration was also determined in human serum by elevating the upper detection range and adjusting the sensitivity of detection via controlling the nanozyme concentration.

Comparison of antioxidant reserve capacity of children with acyanotic & cyanotic congenital heart disease.

BACKGROUND & OBJECTIVES: Oxidative stress can cause many diseases and increases the risk of post-operative complications in children with congenital heart disease. For these reasons, this study was aimed to investigate the differences between cyanotic and acyanotic paediatric patients who underwent heart surgery with markers of oxidative stress. METHODS: Eighty five patients were included in the study. The samples taken before the surgery and within the first 24 h after the surgery were evaluated for haemoglobin (Hb), leukocytes, uric acid, glutathione (GSH), malondialdehyde and total antioxidant capacity. Cyanotic, acyanotic, hyperoxygenated, normo-oxygenated, cardiac surgery with or without cardiopulmonary bypass (CPB) comparisons were made. RESULTS: Positive correlation was found between age and pre-operative total antioxidant status values. Cyanotic and acyanotic patients did not have different antioxidant reserve capacities preoperatively. Although pre-operative thiobarbituric acid reactive substances (TBARS) levels were significantly lower in cyanotic patients, post-operative levels were higher. TBARS levels increased and GSH levels reduced postoperatively. The level of oxygenation did not cause a significant difference on markers of oxidative stress. The duration of CPB did not have negative effects on oxidative stress. INTERPRETATION & CONCLUSIONS: Cyanotic and younger patients were found to be more vulnerable to oxidative stress. The increased levels of TBARS and the decreased levels of GSH could be the indicators of oxidative damage depending on many factors such as surgery, CPB, ischaemia/reperfusion, inflammation, iron overload and oxygenation. The level of oxygenation does not cause a noticeable difference in oxidative stress. CPB causes oxidative stress, but if it is conducted appropriately, the duration of CPB does not cause a significant negative impact on oxidative stress.

Gingival crevicular fluid levels of human beta-defensin-1 in type 2 diabetes mellitus and periodontitis.

OBJECTIVES: Human ß-defensin (hBD)-1 is an important gatekeeper of the gingiva against constant bacterial challenge, and glucose levels are involved in its optimal expression. The aims of the study were to investigate hBD-1 levels in gingival crevicular fluid (GCF) and to compare these levels between type 2 diabetics with or without periodontitis and healthy individuals. MATERIALS AND METHODS: Altogether, 81 subjects were included in the study: 21 subjects with type 2 diabetes mellitus (T2DM) suffering from generalized periodontitis (T2DM + GP), 18 systemically healthy generalized periodontitis patients (GP), 18 periodontally healthy T2DM subjects (T2DM + H), and 24 systemically and periodontally healthy subjects (control). Plaque index (PI), gingival index (GI), probing pocket depth (PPD), and clinical attachment level (CAL) were recorded, and GCF samples were collected. hBD-1 levels in GCF were measured using ELISA. RESULTS: hBD-1 levels were significantly reduced in the T2DM + GP and GP groups. Although PI and GI scores were similar in both periodontally healthy groups, hBD-1 levels were lower in the T2DM + H group. In the whole population, hBD-1 levels correlated negatively with all periodontal parameters. CONCLUSIONS: Both diabetes and periodontitis affect hBD-1 levels in GCF. CLINICAL RELEVANCE: The altered levels of hBD-1 in GCF of diabetics might be associated with the susceptibility of diabetics to periodontitis.

Mycobacterial strains that stimulate the immune system most efficiently as candidates for the treatment of bladder cancer.

BACKGROUND: Intravesical bacillus Calmette-Guérin (BCG) application is widely used in the treatment of superficial bladder carcinoma. Despite being an effective therapy, the pathogenicity and lethal side effects of BCG limits its usage. Intensive research has been carried out to find less toxic and more potent therapeutic agents for the treatment of bladder cancer. Researchers have focused on Mycobacterium phlei as an alternative. The cell wall extract of M. phlei is sufficient for antitumoral activity. Our preliminary experiments indicate that the fractions rich in cell wall proteins cause activation of tumor necrosis factor (TNF)-α and interleukin (IL)-12. This study aims to identify powerful and less harmful mycobacteria among 88 strains in terms of how they stimulate the immune system. METHODS: Eighty-eight mycobacterial strains were grown in Middlebrook 7H9 medium. The bacterial cells were sonicated after heat treatment. The supernatants were incubated with the monocytic cell line THP-1, followed by measurement of TNF-α and IL-12 response. RESULTS AND CONCLUSION: In addition to M. phlei, the following 12 mycobacterial strains were selected as candidates for superficial bladder tumor treatment: M. agri, M. aichiense, M. aurum, M. brumae, M. chitae, M. chubuense, M. diernhoferi, M. gadium, M. murale, M. obuense, M. tokaiense and M. vaccae.