Heterotypic interactions can drive selective co-condensation of prion-like low-complexity domains of FET proteins and mammalian SWI/SNF complex.

Prion-like domains (PLDs) are low-complexity protein sequences enriched within nucleic acid-binding proteins including those involved in transcription and RNA processing. PLDs of FUS and EWSR1 play key roles in recruiting chromatin remodeler mammalian SWI/SNF (mSWI/SNF) complex to oncogenic FET fusion protein condensates. Here, we show that disordered low-complexity domains of multiple SWI/SNF subunits are prion-like with a strong propensity to undergo intracellular phase separation. These PLDs engage in sequence-specific heterotypic interactions with the PLD of FUS in the dilute phase at sub-saturation conditions, leading to the formation of PLD co-condensates. In the dense phase, homotypic and heterotypic PLD interactions are highly cooperative, resulting in the co-mixing of individual PLD phases and forming spatially homogeneous condensates. Heterotypic PLD-mediated positive cooperativity in protein-protein interaction networks is likely to play key roles in the co-phase separation of mSWI/SNF complex with transcription factors containing homologous low-complexity domains.

Heterotypic interactions in the dilute phase can drive co-condensation of prion-like low-complexity domains of FET proteins and mammalian SWI/SNF complex.

Prion-like domains (PLDs) are low-complexity protein sequences enriched within nucleic acid-binding proteins including those involved in transcription and RNA processing. PLDs of FUS and EWSR1 play key roles in recruiting chromatin remodeler mammalian SWI/SNF complex to oncogenic FET fusion protein condensates. Here, we show that disordered low-complexity domains of multiple SWI/SNF subunits are prion-like with a strong propensity to undergo intracellular phase separation. These PLDs engage in sequence-specific heterotypic interactions with the PLD of FUS in the dilute phase at sub-saturation conditions, leading to the formation of PLD co-condensates. In the dense phase, homotypic and heterotypic PLD interactions are highly cooperative, resulting in the co-mixing of individual PLD phases and forming spatially homogeneous co-condensates. Heterotypic PLD-mediated positive cooperativity in protein-protein interaction networks is likely to play key roles in the co-phase separation of mSWI/SNF complex with transcription factors containing homologous low-complexity domains.

The Antimicrobial Effect of Pomegranate Peel Extract versus Chlorhexidine in High Caries Risk Individuals Using Quantitative Real-Time Polymerase Chain Reaction: A Randomized Triple-Blind Controlled Clinical Trial.

The aim of the present study was to compare the antibacterial effectiveness of chlorhexidine and PPE oral rinse on S. mutans, Lactobacilli, and Veillonella, in clinical salivary samples of patients with advanced stages of dental caries at baseline and two and four weeks with PCR technique. This triple-blind randomized clinical trial involved 60 high caries risk adult patients, 19-59 years of age, randomly allocated into two groups of 30 subjects each. The intervention group received pomegranate peel extract mouthwash, whereas the control group received chlorhexidine mouthwash. Unstimulated pooled saliva was collected from the floor of the mouth before and after the intervention. The quantitative real-time polymerase chain reaction was employed to analyze the bacterial copies of each salivary sample at baseline and two and four weeks. The significance level was fixed at 5% (α = 0.05). Overall comparison of antimicrobial effectiveness across both groups revealed insignificant outcomes. The control group evinced a significant reduction in S. mutans between a specific time, i.e., baseline and 4 weeks (p=0.043). PPE oral rinse as a natural product or ecological alternative was effective in disrupting activity across all microorganisms tested in this triple-blind RCT; however, the nutraceutical, when compared to chlorhexidine, was not as effective against S. mutans.

Management of Intracanal Separated File Fragment in a Four-Rooted Mandibular Third Molar.

The success of endodontic therapy is attributed to complete arbitration of the bound entities concealed within the complexity and absolute disinfection of the root canal system, thus, deeming it mandatory to effectively negotiate and overcome the challenges posed by obstruction, either iatrogenic or anatomic. To achieve this, considerable depth of knowledge and expertise with reference to variations in root canal morphology and clinical mishap management is substantially as important as developing fine observation skills in conjunction with an appropriate armamentarium and a keen sense of determination, thereby enhancing one's clinical acumen by several folds. In the present case, following rubber dam isolation, the temporary restoration was removed, and the remaining carious dentin was excavated. Endodontic access cavity was refined and explored with a DG-16 probe, following which three separate canal orifices were identified in the pulp chamber floor (mesiobuccal, mesiolingual, and distal). On further observation under a surgical operating microscope and continuous exploration with the DG-16 probe, a fourth canal was found in the mesial aspect of the tooth (middle mesial). With instrumentation, it was confirmed that a fractured object was indeed present at the apical third of the mesiolingual root of tooth 38. Bypassing of the fractured fragment was initiated with a size 10 SS K-file coupled with copious irrigation with 3% sodium hypochlorite. In the present case report, four distinct canals comprising 3 mesial and 1 distal canal were recognized, and the fractured instrument in one of the canals was bypassed successfully.

Biomolecular Condensates: Sequence Determinants of Phase Separation, Microstructural Organization, Enzymatic Activity, and Material Properties.

This perspective article highlights recent progress and emerging challenges in understanding the formation and function of membraneless organelles (MLOs). A long-term goal in the MLO field is to identify the sequence-encoded rules that dictate the formation of compositionally controlled biomolecular condensates, which cells utilize to perform a wide variety of functions. The molecular organization of the different components within a condensate can vary significantly, ranging from a homogeneous mixture to core-shell droplet structures. We provide many examples to highlight the richness of the observed behavior and potential research directions for improving our mechanistic understanding. The tunable environment within condensates can, in principle, alter enzymatic activity significantly. We examine recent examples where this was demonstrated, including applications in synthetic biology. An important question about MLOs is the role of liquid-like material properties in biological function. We discuss the need for improved quantitative characterization tools and the development of sequence-structure-dynamics relationships.

Concentrated Growth Factor: A Novel Platelet Concentrate for Revascularization of Immature Permanent Teeth-A Report of Two Cases.

This article elucidates the utilization of a novel platelet concentrate-concentrated growth factor (CGF) for rapid and successful healing outcome in regenerative endodontics. This case report focusses on two cases: 23-year-old and 21-year-old patients with incomplete root formation and periapical lesion. Case 1 and case 2 are classified as stage IV and stage II, respectively, in accordance with Cvek's classification of open apex and had varied outcomes. The extent of open apex, root dentin thickness, and lesion were assessed using periapical radiograph and CBCT. Revascularization procedure was carried out after obtaining patient consent. Following bleeding induction, CGF was prepared, placed, and condensed using pluggers in the root canal space, followed by the placement of mineral trioxide aggregate (MTA) up to the level of CEJ. At 1-year follow-up, apical closure with increased root dentin thickness and reduced periapical radiolucency was evident.

Concentrated Growth Factor - Surgical Management of Large Periapical Lesion Using a Novel Platelet Concentrate in Combination with Bone Graft.

Although endodontic therapy is typically successful, in approximately 10%-15% of the cases, symptoms can persist or reoccur. Periapical surgery is the preferred treatment of choice in failed root canal therapy, chronic periapical lesion, persistent apical periodontitis, etc., i.e., when conventional treatment modalities fail. Over the past few decades, although the list of indications for endodontic surgery has diminished, there exist definite cases in which the tooth cannot be retained without surgery. This case report, however, sheds light on the incorporation of a novel autologous platelet concentrate-concentrated growth factor (CGF) coupled with an osseograft in surgical endodontic procedure to ensure a swift and successful recovery of the periapical region subjected to extensive lesions. The use of an osseograft combined with CGF has numerous advantages as well due to the formation of sticky bone. There are no articles published in the literature with respect to the potent application of CGF and bone graft (sticky bone) in large periapical lesions to aid in the reparative process. In this case report, the 1-year follow-up radiographs and cone-beam computed tomography showed complete healing of the hard and soft-tissue lesions that conform to achieving repair and regeneration at a rapid rate in extensive periapical lesions.

Identifying sequence perturbations to an intrinsically disordered protein that determine its phase-separation behavior.

Phase separation of intrinsically disordered proteins (IDPs) commonly underlies the formation of membraneless organelles, which compartmentalize molecules intracellularly in the absence of a lipid membrane. Identifying the protein sequence features responsible for IDP phase separation is critical for understanding physiological roles and pathological consequences of biomolecular condensation, as well as for harnessing phase separation for applications in bioinspired materials design. To expand our knowledge of sequence determinants of IDP phase separation, we characterized variants of the intrinsically disordered RGG domain from LAF-1, a model protein involved in phase separation and a key component of P granules. Based on a predictive coarse-grained IDP model, we identified a region of the RGG domain that has high contact probability and is highly conserved between species; deletion of this region significantly disrupts phase separation in vitro and in vivo. We determined the effects of charge patterning on phase behavior through sequence shuffling. We designed sequences with significantly increased phase separation propensity by shuffling the wild-type sequence, which contains well-mixed charged residues, to increase charge segregation. This result indicates the natural sequence is under negative selection to moderate this mode of interaction. We measured the contributions of tyrosine and arginine residues to phase separation experimentally through mutagenesis studies and computationally through direct interrogation of different modes of interaction using all-atom simulations. Finally, we show that despite these sequence perturbations, the RGG-derived condensates remain liquid-like. Together, these studies advance our fundamental understanding of key biophysical principles and sequence features important to phase separation.