Biomolecules

Sequence homology in pre-divergence tRNA species revealed cofactor/adaptors cognate for 16 amino acids derived from oxaloacetate, pyruvate, phosphoglycerate, or phosphoenolpyruvate were related. Synthesis path-distances of these amino acids correlated with phylogenetic depth, reflecting relative residue frequency in pre-divergence sequences. Both metrics were thus aligned in the four sub-families of the Aspartate family, and misaligned in the small Glutamate family; a functional difference was noted and seen to parallel synthetase duality. Amino acid synthetic order, based on path-distances, indicate NH4+ fixer amino acids, Asp1, Asn2, and homologues, Glu1, Gln2, formed the first code. Together with a termination signal, they acquired all four triplet 4-sets in the XAN column (X, 5 coding site; N, any 3-base). An invariant mid-A conformed with pre-code translation on a poly(A) template by a ratchet-equipped ribosome resulting in random, polyanionic polypeptides. Code expansion occurred in a compact (mutation minimizing) columnwise pattern, (XAN) XCN XGN XUN; with increasing mean path-distance, (1.5) 4 5 7 steps; amino acid side-chain hydrophobicity, (+6.6) -0.8 -1.5 -3.2 kcal/ mol; codon:anticodon H bond enthalpy (selection for bond-strength), (-12.5) -17.5 -15.5 -14.5 kcal/ mol; and precursorspecific 5-base, A, oxaloacetate, G, pyruvate/oxaloacetate, U, phosphoglycerate/oxaloacetate, C, oxoglutarate, forming horizontal code domains. Codon bias evidence corroborated the XCN XGN step in expansion, and revealed row GNN coevolved with ANN, on correction for overprinting. Extended surfaceattachment (Fajan-Paneth principle) by pro-Fd[5] and bilayer partitioning by H+ ATPase proteolipid-h1 subunit implicated expansion phase proteins in driving increases in side-chain hydrophobicity during code expansion. 3-Base recruitment in pre-assigned codon boxes added six long (9-to 14-step) path amino acid, bearing a basic, or cyclic, side-chain; 3 of 4 polar, post-expansion amino acids acquired polar cluster NAN codons and 2 of 3 non-polar (Ile7 included) acquired non-polar cluster NUN codons, yieldng a split-box pair homology of p = 5.4x10-3. All eight overprinted codon boxes (GAYR for Asp1, Glu1 included) exhibit weak codon:anticodon H-bond enthalpy, -14 kcal/mol or higher, in three of six distinct code enthalpy states.

Glioblastoma multiforme (GBM) is the most aggressive type of brain cancer with a poor prognosis. GBM cells, developing in the environment of neural tissue, often exploit neurotransmitters and their receptors to promote their growth and invasion. Nicotinic acetylcholine receptors (nAChRs) play a crucial role in the central nervous system signal transmission, are widely represented in the brain, the GBM cells expressing several subtypes of nAChRs which are suggested to transmit signals from neurons, thus promoting tumor invasion and growth. Functional 1*, 7 and 9 nAChRs are demonstrated on several patient-derived GBM neurosphere cultures and U87MG cell line using neurotoxins and fluorescent calcium assay. Selective 1*, 7 and 9 nAChR antagonists stimulated cell growth in presence of nicotinic agonists. Choline, normally present in blood, is capable of activating 1*, 7 and 9 nAChR subtypes, mediates the antagonists influence on cell proliferation. Several cultivating conditions have been shown to directly change sensitivity of primary GBM lines to nAChR ligands. Thus, results of in vitro testing of nAChR ligands on GBM lines should be interpreted and reviewed in cell culture conditions-aware manner.

The contribution of redox active properties of cysteines in intrinsically disordered regions (IDRs) of proteins is not very well acknowledged. Despite of providing structural stability and rigidity, intrinsically disordered cysteines are exceptional redox sensors and the redox status of the protein defines its structure. Experimental evidence suggests that the conformational heterogeneity of cysteines in intrinsically disordered proteins (IDPs) is related to numerous functions including regulation, structural changes and fuzzy complex formation. The unusual plasticity of IDPs make them suitable candidate to interact with many clients under specific conditions. Binding capabilities, dimerization and folding or unfolding nature of IDPs upon interaction with multiple clients assign distinct conformational changes associated with disulfide formation. Here we are going to focus on redox activity of IDPs, their dramatic roles that are not only restricted to cellular redox homeostasis and signaling pathways but also provide antioxidant, anti-apoptotic, binding and interactive power.

Multiple paracrine factors regulate barrier properties of human brain capillary endothelial cells (BCECs). Understanding precise mode of action of these factors remains a challenging task because of the limited availability of functionally competent BCECs and use of serum-containing medium. In the present study we employed defined protocol for producing BCECs from human inducible pluripotent stem cells. We found that autocrine secretion of basic fibroblast growth factor (bFGF) is necessary for the establishment a tight BCECs barrier, as revealed by measurements of trans-endothelial electric resistance (TEER). In contrast, exogenous bFGF in concentrations exceeding 4 ng/ml inhibited TEER and proliferation of BCECs in a concentration-dependent manner. Exogenous bFGF did not significantly affect expression and distribution of tight junction proteins claudin-5, occludin and ZO-1. Treatment with FGF receptor blocker PD173074 (15 M) suppressed inhibitory effects of bFGF and induced nuclear translocation of protein ZO-1. Inhibition of phosphoinositide 3-Kinase (PI-3K) with LY294002 (25 M) significantly potentiated inhibitory effect of bFGF on TEER indicating that PI-3K signalling pathway partially suppress inhibitory effects of bFGF on TEER. In conclusion we show that autocrine bFGF secretion is necessary for the proper barrier function of BCECs, whereas exogenous bFGF suppresses barrier resistance in a concentration-dependent manner. Our findings demonstrate a dual role for bFGF in the regulation of BCEC barrier function.

Stress granules are cytoplasmic inclusions1 with cyto-protective functions2-6 assembling in response to stress. They are now accepted to be part of the pathological mechanism in several diseases, from cancer to neurodegenerative disorders7-10. However, the field is still struggling to find common regulators of their assembly and function7,11. In this study, we describe an unraveled mechanism involving lipid raft, via gangliosides and cholesterol, in the regulation of SG formation. This is the first report about regulation of SG by the cell membrane composition. This discovery could have a significant impact on the understanding of several disease mechanism. MATERIAL AND METHODESO_ST_ABSCell culture & cell treatmentC_ST_ABSMDA-MB-231 (ATCC) and SH-SY5Y (ATCC) cells were maintained at 37 {degrees}C with 5% CO2 in Gibco Dulbeccos Modified Eagle Medium: Nutrient Mixture F12 (DMEM-F12, GIBCO, Waltham, MA, USA) supplemented with 10% Fetal Bovine Serum (FBS, Eurobio, Les Ulis, France), 20 mM HEPES (GIBCO, Waltham, MA, USA), 1X Penicillin streptomycin (GIBCO, Waltham, MA, USA). Cells are treated with methyl-{beta}-cyclodextrine (M{beta}CD) (MDA-MD-231 5mM, SH-SY5Y 1mM) 48h before experimentation, or with d,l-threo-l-Phenyl-2-hexadecanoylamino-3-morpholino-1-propanol (PPMP) (MDA-MD-231 5M, SH-SY5Y 10M) for 24h. ImmunofluorescenceCells were seeded on coverslips, treated 48h with PPMP or 24h with M{beta}CD before the experiment. After stress treatment, cells are washed quickly with PBS before to be fixed for 15min with 4% Paraformaldehyde (Thermo Scientific, Waltham, MA, USA) in PBS. Cells were then permeabilized and blocked with IF buffer PBS-0.3% TX100 (Euromedex, Souffelweyersheim, France), 1% Glycine (Sigma, Saint-Louis, MO, USA), 5% Normal Horse Serum (Sigma, Saint-Louis, MO, USA), 5% Bovine Serum Albumine (Sigma, Saint-Louis, MO, USA) for 30 min at room temperature. Primary antibodies (Table S1) were diluted in IF buffer and incubated 1 h at room temperature. Coverslips were washed three times for 5 min with 1X PBS between primary and secondary antibody incubations. Subsequently, secondary antibodies (Table S1) were added along with DAPI for 1 h at room temperature in IF buffer. Cells were washed extensively 3 times with 1X PBS and mounted with ProLong Antifade reagent (Invitrogen, Carlsbad, CA, USA). Pictures were taken with confocal microscope LEICA LSM880 Western BlotFollowing drug(s) treatment(s), cells were washed with phosphate-buffered saline (PBS) and lysed in RIPA buffer (150mM NaCl, 50mM Tris pH7.4, 1%TritonX100, 0.1% SDS, 1% Sodiun desoxycholate) with Halt phosphatase and protease inhibitors (Thermo Scientific). Laemmlis sample buffer supplemented was added to samples to 1X final concentration. Samples were boiled, 5min 95{degrees}C before being loaded on a NuPAGE 4-12% Bis-Tris gel (Invitrogen) and transferred to nitrocellulose membrane (GE Healthcare). Membranes were blocked with Tris-buffered saline with 0.1% Tween-20 (TBS-T) with 5% BSA for at least 30 min at room temperature. Antibodies were diluted in 2.5% BSA in TBS-T. Primary antibodies were incubated overnight at 4{degrees}C and secondary antibodies for 1 h at room temperature; mouse anti G3BP1 antibody (Santa Cruz sc-365338), rabbit anti Caprin-1 antibody (ProteinTech Group 15112-1-AP), mouse anti puromycin antibody (Millipore MABE342), mouse anti GAPDH (abcam ab8245). Antibody detection was performed using SuperSignal West Pico Chemiluminescent Substrate (Thermo Scientific). Revelation of the blot was made using G:BOX machine (Syngene) via the GeneSys software. Blot analysis and quantification were done using ImageJ software. Statistical AnalysisStatistical analyses were done on 3 independent experiments. Student T-TEST were performed to compare control to PPMP samples or control to M{beta}CD samples.

The highly conserved Hsp90 chaperones control stability and activity of many essential signaling and regulatory proteins including many protein kinases, E3 ligases and transcription factors. Thereby, Hsp90s couple cellular homeostasis of the proteome to cell fate decisions. High-throughput mass spectrometry revealed 178 and 169 posttranslational modifications (PTMs) for human cytosolic Hsp90 and Hsp90{beta}, but for only a few of the modifications the physiological consequences are investigated in some detail. In this study, we explored the suitability of the yeast model system for the identification of key regulatory residues in human Hsp90. Replacement of three tyrosine residues known to be phosphorylated by phosphomimetic glutamate and by non-phosphorylatable phenylalanine individually and in combination influenced yeast growth and the maturation of 7 different Hsp90 clients in distinct ways. Furthermore, wild-type and mutant Hsp90 differed in their ability to stabilize known clients when expressed in HepG2 HSP90AA1-/- cells. The purified mutant proteins differed in their interaction with the cochaperones Aha1, Cdc37, Hop and p23 and in their support of the maturation of glucocorticoid receptor ligand binding domain in vitro. In vivo and in vitro data correspond well to each other confirming that the yeast system is suitable for the identification of key regulatory sites in human Hsp90s. Our findings indicate that even closely related clients are affected differently by the amino acid replacements in the investigated positions, suggesting that PTMs could bias Hsp90s client specificity.

Aim & ObjectivesThe aim of the present study is to evaluate the regeneration efficacy of rhEGF impregnated in collagen membrane for the management of Millers class I & class II gingival recession defects. Patients and methods18 patients with 30 Millers class I & class II gingival recession defects were treated with one of the following interventions and randomly allocated into each of the following experimental groups; Test group: rhEGF impregnated in collagen membrane, Control group: plain collagen membrane. Clinical measurements at baseline, 3 months and 6 months included decreased probing depth, recession depth and increase in width of keratinized gingiva. ResultsThere was an improvement in tissue biotype in test group and statistically significant increase in KGW from baseline to 3 months which remained constant from 3 months to 6 months(p[≤]0.001) in both the groups. Similarly, RD shows constant increase from baseline to 6 months in test group whereas there is reduction in control group (p[≤]0.003). There was significant difference in clinical parameters in both test and control groups. All the patients had an uneventful healing phase. ConclusionThe beneficial effects of rhEGF resulted in healthy wound healing process with less scarring offers more potential properties showed promising results over collagen membrane. Further larger samples are required to confirm the efficacy of rhEGF in root coverage for soft tissue regeneration.

BACKGROUNDTooth loss has been established as a correlate with an increased risk of cardiovascular disease (CVD) and hypertension. However, the influence of complete denture usage on hypertension remains inadequately explored in scientific literature. METHODSThis case-control study evaluated the microbial load of the biofilm of dentures and the palate, salivary levels of cytokines (IL-2, IL-4, IL-6, IL-10, TNF-, IFN-{gamma}, and IL-17) and Salivary Flow (SF) of healthy (CG), controlled hypertensives (G1), underreported hypertensives (G2) and uncontrolled hypertensives (G3). The sample was characterized by sociodemographic data, clinical information, systolic (SBP), and Diastolic Blood Pressure (DBP). The microbial load of Candida spp., Staphylococcus spp., enterobacteria, and mutans group streptococci was evaluated by quantifying colony-forming unit (CFU), SF of unstimulated saliva by mL per minute, and salivary cytokines by flow cytometry. RESULTS80 patients were evaluated (66{+/-}7.2 years). The time of edentulism was longer in G3 and positively associated with SBP. The CFU of mutans group streptococci on the denture was higher in G3 and showed a negative association with smoking habit, and this had a positive association with salivary cytokines (IL-4, IL-2, IL-17, IFN-{gamma}), diabetes, and CVD. Patients in group G3, who only use upper dentures, had significantly higher SBP (p=0.024) and levels of IL-2 (p=0.024). CONCLUSIONSTime of edentulism may play a role in hypertension. Smoking habits modulated microbiota and interleukins, especially in diabetic and CVD patients. Furthermore, non-functional dentures had an association with hypertensive patients not controlled by medication, reflected in an increase in SBP and IL-2.

It is well known that hypersensitivity affects patients recently treated with scaling and root planing. Some studies have demonstrated that photobiomodulation (PBM) can alleviate dentinal hypersensitivity by modulating pain. However, to date, there is no established protocol for its application after scaling and root planning. To evaluate tooth hypersensibility after photobiomodulation in sensitive scaling and root planning treated teeth. Study design: Randomized, controlled, double-blind split-mouth clinical trial. Methods: Forty-four patients with dentin sensibility after non-surgical scaling and root planning (SRP) will be randomly included in 2 groups: Experimental Group: SRP+ Photobiomodulation (PBM) (660nm, 100W, area 0,5cm2, 200w/cm2, 30 seconds, 3 J, 6J/cm2) and Control Group: Scaling and root planning +FBM simulation. After 7 days of scaling and root planning, all patients will be evaluated for hypersensibility. The cutoff of VAS will be 3. These patients will be included in the study. The primary outcome of the study will be the assessment of dentin hypersensitivity after 7 days of RAR measured with the visual analog scale (VAS). Also, it will be assessed the impact of oral health on the participants quality of life, with the OHIP-14 questionnaire. The use of analgesics (paracetamol) will be prescribed as needed and the amount of medication will be calculated. These outcomes will be evaluated after 7 days and 1 month of application. If the data are normal, they will be submitted to the ANOVA test - one way. Data will be presented as means {+/-} SD and the p-value will be set to < 0.05.

Background and AimsSevere alcoholic hepatitis (SAH) has a high mortality and corticosteroid therapy is effective in 60% patients. Reliable indicators of response to therapy and mortality in SAH are needed. A total of 223 SAH patients, 70 in derivative [50 responders (R) and 20 non-responders (NR)] and 153 in validation cohort [136R, 17NR] were subjected to plasma metabolic/meta-proteomic analysis using UHPLC-HRMS and validated using Machine-Learning (ML). Temporal metabolic changes were assessed using Weighted Metabolome Correlation Network Analysis (WMCNA). Functionality (inflammatory-nature, effect on membrane integrity and glucocorticoid receptor) of non-response indicator was assessed in-vitro on primary healthy neutrophils or mice enterocytes. Baseline plasma metabolomics and meta-proteomics clearly discriminated NR and showed significant increase in urobilinogen (3.6-fold), cholesterol sulfate (6.9-fold), Adenosine monophosphate (4.7-fold) and others (p<0.05, FC>1.5, FDR<0.01). Increase in alpha/beta diversity, biosynthesis of secondary metabolites was a characteristic feature of NR (p<0.05). NR were metabolically inactive however R showed temporal change in the metabolite expression post-corticosteroid therapy (p<0.05). Plasma urobilinogen predicted non-response [AUC=0.94] with a hazard-ratio of 1.5(1.2-1.6) and cut-off >0.07mg/ml segregated non-survivors (p<0.01) and showed >98% accuracy using ML. Plasma urobilinogen directly correlated with circulating bacterial peptides linked to bilirubin to urobilinogen metabolising bacteria (r2>0.7;p<0.05). Urobilinogen induced neutrophil activation, oxidative-stress and pro-inflammatory cytokines (CXCR1, NGAL, NOXO1, NOX4, IL15, TNF and others, p<0.05), promoted corticosteroid resistance by increasing the expression of GR-Beta and trans-repression genes under GR-alpha (inflammatory-NFkB, MAPK-MAP) and reducing GR-alpha, and transactivation (anti-inflammatory) gene levels. Urobilinogen also promoted leaky gut by deregulating intestinal membrane junction proteins. ConclusionPlasma metabolome/meta-proteome can stratify pre-therapy steroid response. Increase in plasma Urobilinogen pedals a vicious cycle of bacterial translocation and increase in inflammation and corticosteroid non-response in SAH patients.

Amyotrophic lateral sclerosis (ALS) is an irreversible neurodegenerative disease caused by the degeneration of motor neurons, and cytoskeletal instability is considered to be involved in neurodegeneration. A hexanucleotide repeat expansion of the C9orf72, one of the most common causes of familial ALS, produces toxic proline:arginine (PR) poly-dipeptides. PR poly-dipeptides binds polymeric forms of low complexity sequences and intracellular puncta, thereby altering intermediate filaments (IFs). However, how PR poly-dipeptides affect the cytoskeleton, including IFs, microtubules and actin filaments, remains unknown. Here we performed a synthetic PR poly-dipeptide treatment on mammalian cells and investigated how it affects morphology of cytoskeleton and cell behaviors. We observed that PR poly-dipeptide treatment induce the degradation of vimentin bundles at perinucleus and dissociation of {beta}-tubulin network. PR poly-dipeptides also lead to alteration of actin filaments toward to cell contours and strength cortical actin filaments via activation of ERM (ezrin/radixin/moesin) proteins. In addition, we found that PR poly-dipeptides promote phosphorylation of paxillin and recruitment of vinculin on focal adhesions, which lead to maturation of focal adhesions. Finally, we evaluated the effects of PR poly-dipeptides on mechanical property and stress response. Interestingly, treatment of PR poly-dipeptides increased the elasticity of the cell surface, leading to maladaptive response to cyclic stretch. These results suggest that PR poly-dipeptides cause mechanically sensitive structural reorganization and disrupt the cytoskeleton architecture.

Based on our previous findings, we hypothesized that the long non-coding RNA RP11-502I4.3 may be involved in angiogenesis associated with Diabetic retinopathy (DR). We investigated the role of RP11-502I4.3 in DR by examining its regulation of vascular endothelial growth factor (VEGF). We assessed differences in RP11-502I4.3 expression between the normal control group and streptozotocin-induced diabetic rats or high glucose (HG)-stimulated human retinal microvascular endothelial cells (HRMECs). VEGF expression was measured with and without lentiviral vectors overexpressing RP11-502I4.3. We analyzed the structural and functional alterations related to DR. Our analysis revealed that RP11-502I4.3 expression was lower in the retinas of diabetic rats and in HG-stimulated HRMECs compared with normal glucose conditions. Overexpressing of RP11-502I4.3 resulted in decreased VEGF levels. Diabetic rats exhibited retinopathy characterized by thinning of the retinal layer thickness, structural changes in the inner and outer nuclear layers, a reduced count of retinal ganglion cells, and the presence of acellular capillaries. The proliferative activity, migration count, and tube formation ability of HG-treated HRMECs were significantly higher than those of the normal control group; however, these changes were delayed by RP11-502I4.3 overexpression. RP11-502I4.3 downregulation in DR appears to promote angiogenesis.

The intracellular transport system is pivotal for cellular function and integrity, facilitated by cytoskeletal motor proteins such as dynein, which traverse along microtubules (MTs). The heterogeneity of the tubulin isotypes composing MTs introduces functional diversity, potentially affecting cytoskeletal motor proteins interactions with the MT. This in silico study investigated the influence of amino acid sequence variations in the C-terminal tails (CTTs) of six different Homo sapiens tubulin isotypes, TUBB2A, TUBB2B, TUBB2C, TUBB3, TUBB4A, and TUBB5, highly expressed in human brain tumors, and assessed the isotypes effect on the binding of motor protein dynein to MT. Among these isotypes, TUBB2A, TUBB2B, and TUBB2C were found to affect conformational motions of the dyneins microtubule-binding domain (MTBD) and stalk domain. The investigation highlighted the novel role of isotype-specific variations in lateral interactions between tubulin protofilaments (PFs) in determining the proximity of the {beta}-CTT of the adjacent PF to the MTBD, potentially affecting dyneins motility and suggesting how changes in isotype expression directly influence dyneins velocity and processivity and contribute to transport defects associated with neurological disorders and cancers. Isolating specific tubulin isotypes experimentally is challenging due to their high sequence similarity and complex interactions with other microtubule-associated proteins. This makes it challenging to distinguish between different tubulin isotypes and their effects, particularly in tissues where multiple isotypes are co-expressed. Additionally, these isotypes are heavily modified in vivo by post-translational modifications, which further complicate the isolation of a single, unmodified tubulin isotype. As a result, computational approaches have been necessary in this study for exploring these effects in a controlled, isotype-specific manner.

The neurotrophin receptors p75 and TrkA play an important role in the development and survival of the nervous system. Biochemical data suggest that p75 and TrkA regulate the activities of each other. For instance, p75 is able to regulate the response of TrkA to lower concentrations of NGF and TrkA promotes p75 shedding by -secretases in a ligand-dependent manner. The current model is that p75 and TrkA are regulated by means of a physical direct interaction, however the nature of such interaction has been elusive so far. Here using NMR in micelles, multiscale molecular dynamics (MD), FRET and functional studies we identified and characterized the direct interaction between TrkA and p75 through the transmembrane domains (TMDs). MD of p75-TMD mutants suggests that although the interaction between TrkA and p75 TMDs is maintained, a specific protein interface is required to facilitate TrkA active homodimerization in the presence of NGF. The same mutations in the TMD protein interface of p75 reduced the activation of TrkA by NGF and cell differentiation. In summary we provide a structural model of the p75/TrkA receptor complex stabilized by transmembrane domain interactions.

The CLIC family of proteins display the unique feature of altering their structure from a soluble form to a membrane-bound chloride channel. CLIC1, a member of this family, can be found in the cytoplasm or in nuclear, ER and plasma membranes, with membrane overexpression linked to tumour proliferation. The molecular switch promoting CLIC1 membrane insertion has been related to environmental factors, but still remains unclear. Here, we use solution NMR studies to confirm that both the soluble and membrane bound forms are in the same oxidation state. Our data from fluorescence assays and chloride efflux assays indicate that Ca2+ and Zn2+ trigger association to the membrane into active chloride channels. We use fluorescence microscopy to confirm that an increase of the intracellular Ca2+ leads to re-localisation of CLIC1 to both plasma and internal membranes. Finally, we show that soluble CLIC1 adopts an equilibrium of oligomeric species, and Ca2+/Zn2+ mediated membrane insertion promotes the formation of a tetrameric assembly. Thus, our results identify Ca2+ and Zn2+ binding as the molecular switch promoting CLIC1 membrane insertion.\n\nSIGNIFICANCE STATEMENTCLIC1, a member of the CLIC family of proteins, is expressed as a soluble protein in cells but can insert in the membrane forming a chloride channel. This chloride channel form is upregulated in different types of cancers including glioblastoma and promote tumour invasiveness and metastasis. The factors promoting CLIC1 membrane insertion nor the mechanism of this process are yet understood. Here, we use a combination of solution NMR, biophysics and fluorescence microscopy to identify Ca2+ and Zn2+ binding as the switch to promote CLIC1 insertion into the membrane to form active chloride channels. We also provide a simple mechanism how such transition to the membrane occurs. Such understanding will enable subsequent studies on the structure of the chloride channel form and its inhibition.

The control of Hsp70 functions has been related to the modulation of ATP hydrolysis and substrate capture by Hsp40. Structural and biophysical analyses of Hsp40 variants and their interactions with Hsp70 have identified key residues for this functional control mechanism. Conserved residues in both Hsp40 and Hsp70 have revealed conserved interactions that link Hsp40 binding to the catalytic residues within Hsp70. The current work investigates the effect of documented J-domain dysfunctional mutations (i.e. D35N, H33Q) on the described interaction linkage. Molecular dynamics simulations were used to compare the persistence of individual bond types (i.e. H-bonds, salt bridges, hydrophobic interactions) between Hsp70 and the bound forms of functional and dysfunctional Hsp40 variants. The generated data suggests the involvement of both direct and allosteric effects for the tested mutations. The observed changes relate mutations in the conserved HPD tripeptide of Hsp40 to alterations in the interaction network that induces Hsp70 chaperone functions. STATEMENT OF SIGNIFICANCEThe significance of the work may be summarized as follows. First, the interaction network for the simulated systems were observed to be different from one previously proposed for a disulfide linked complex (9). This may be attributed to altered residue movement and interactions without the restrictions set by the disulfide link. These results support the use of in silico methods to refine investigations of molecular contacts, particularly for systems, whose in vitro structural elucidation are difficult to achieve without modifications. Second, key interactions for intermolecular and intramolecular contacts were observed within a short simulation time (0.1 ns) matched those from much longer runs (500 ns) (4). This result highlights the possibility of identifying key interactions with relatively low computational cost.

Background and ObjectiveThis study aimed to compare the push-out bond strength of fiber posts cemented with three different types of cements: glass ionomer, self-etch resin, and self-adhesive resin cement. The objective was to identify which cement provides the most effective bonding in different sections of the root canal. MethodsThirty extracted central teeth were prepared and divided into three groups, each receiving a different type of cement. The roots underwent standard preparation, including trimming, manual and mechanical filing, and chemical treatment. The push-out test was employed to measure the bond strength of the fiber posts in the coronal, middle, and apical sections of the root canal. ResultsThe study revealed that in the coronal section, there were no significant differences among the groups. However, in the middle and apical sections, both the self-adhesive and self-etch groups demonstrated a statistically significant increase in bond strength compared to the glass ionomer group. ConclusionThe findings suggest that the choice of cement significantly affects bond strength, particularly in the coronal section of the root canal. Self-adhesive resin cements emerge as a preferred option due to their higher bond strength. This study provides crucial insights for dental practitioners in selecting appropriate cements for different root canal sections, enhancing the longevity and effectiveness of dental restorations.

ObjectiveSelf-adhesive resin cements are easy to use and do not need further preparation but their bonding ability to dentin is somehow questionable.Ddentin preparation with acidic solutions and therefore removing smear layer can increase bond strength of self-adhesive resin cements to dentin. As a matter of fact it is assumed that deproteinization of dentin can increase contact between cement and dentin. In the present study the effect of deproteinization of dentin with different concentrations and times of sodium hypochlorite on the push out bond strength of resin cement to dentin is assessed. Materials and methods60 third molar teeth were selected and divided to 4 groups consisting of 5% and 20% concentrations and 2 and 10 minutes of using. Samples were randomly divided into six groups of ten. All samples used size 2 Whitepost FGM fiber posts (FGM, Joinville, SC, Brazil), with a diameter of 1.2 mm. Samples were cemented using dual-cure self-adhesive TheraCem (Bisco, USA), cured for 40 seconds with an LED Plus device from Woodpecker made in China All the specimens were then mounted in plastic cylinders. After 24 hours they were cut with 0.2 mm thickness diamond disc to two coronal and apical parts. Push out strength test was done with Instron 1122R (Universal Testing Machine). ResultsIncreasing the concentration and using time of sodium hypochlorite increased push out bond strength. DiscussionDeproteinization not only can increase push out bond strength but also increase time and concentration can elevate bond strength measures.

Aim & ObjectivesThe aim of the present study was to evaluate the effect of Stevia rebaudiana bertoni on GCF glucose levels and GCF bio-markers in diabetic patients with periodontitis. Patients and methods19 subjects were participated in the study. Randomly, a quadrant was allotted as test site for placing Stevia gel and other quadrant was allotted as a control site for placing placebo in the gingival sulcus having PD[&ge;] 5mm after performing thorough scaling and root planing. GCF samples was collected using sterile paper strips at baseline i.e., after scaling and root planing, 3 months and 6 months using intra-crevicular superficial method. GCF samples was eluted from the strips by placing them in Eppendorf(R) tubes that contained 500 micro-litre of buffer and will be stored at -80 until analysis was done. The levels of GCF glucose and GCF bio-markers was evaluated by using commercially available ELISA kit. ResultsStevia gel was effective in decreasing the GCF glucose and increasing ghrelin levels in diabetic patients with periodontitis. There was significant difference in clinical parameters in both test and control groups. ConclusionThis study concluded that application of Stevia gel in gingival crevice may be of value in controlling diabetes and periodontitis at a time.

AimsIn most ofcases, clinical parameters associated with poor prognosis are the same as the factors associated with increased risk, but the relationship between risk and prognosis remains unclear.The objective of this study was to evaluate the correlation between measured parameters of predictive risk and prognosisin subjects with chronic periodontitis. Methods300 subjects participated in the study. Modified periodontal risk assessment model (MPRA) was used to assess the risk and prognosis was evaluated by using McGuire and Nunn prognostic criteria. ResultsAmong the subjects, 57.3%, 38% and 4.7% were categorized as having high, low and medium risk respectively. Assessment of prognosis among study subjects showed that 38.0%, 24.0%, 17.7%, 17.0%, 2.0%and1.3% had good, fair, excellent, poor, hopeless and questionable prognosis respectively. Though majority of the subjects had good prognosis (114 subjects;38%), there was a substantial variability in the distribution of the measured parameters as per the risk scores within this cohort. A strong positive correlation was seen between prognosis and probing depth (PD)[&ge;]5mm. There was a weak, but statistically significant correlation between predictive risk from MPRA and various types of prognosis(rs=0.507;p<0.001). ConclusionThe measures used to assess risk and prognosis are almost similar;butthe weak correlation between risk and prognosisseems to suggest that an increased risk of developing periodontal disease need notnecessarily indicate a bad prognosis.