Rainbow trout DUBA inhibits type I interferon signaling by deubiquitinating TRAF3.

Deubiquitinating enzyme A (DUBA), a member of the ovarian tumor (OTU) subfamily of deubiquitinases (DUBs), is recognized for its negative regulatory role in type I interferon (IFN) expression downstream of Toll-like receptor 3 (TLR3). However, its involvement in the TLR3 signaling pathway in fish remains largely unexplored. In this study, we investigated the regulatory role of DUBA (OmDUBA) in the TLR3 response in rainbow trout (Oncorhynchus mykiss). OmDUBA features a conserved OTU domain, and its expression increased in RTH-149 cells following stimulation with the TLR3 agonist poly(I:C). Gain- and loss-of-function experiments demonstrated that OmDUBA attenuated the activation of TANK-binding kinase 1 (TBK1), resulting in a subsequent reduction in type I IFN expression and IFN-stimulated response element (ISRE) activation in poly(I:C)-stimulated cells. OmDUBA interacted with TRAF3, a crucial mediator in TLR3-mediated type I IFN production. Under poly(I:C) stimulation, there was an augmentation in the K63-linked polyubiquitination of TRAF3, a process significantly inhibited upon OmDUBA overexpression. These findings suggest that OmDUBA may function similarly to its mammalian counterparts in downregulating the poly(I:C)-induced type I IFN response in rainbow trout by removing the K63-linked ubiquitin chain on TRAF3. Our study provides novel insights into the role of fish DUBA in antiviral immunity.

Dopamine D2 receptors in WFS1-neurons regulate food-seeking and avoidance behaviors.

The selection and optimization of appropriate adaptive responses depends on interoceptive and exteroceptive stimuli as well as on the animal's ability to switch from one behavioral strategy to another. Although growing evidence indicate that dopamine D2R-mediated signaling events ensure the selection of the appropriate strategy for each specific situation, the underlying neural circuits through which they mediate these effects are poorly characterized. Here, we investigated the role of D2R signaling in a mesolimbic neuronal subpopulation expressing the Wolfram syndrome 1 (Wfs1) gene. This subpopulation is located within the nucleus accumbens, the central amygdala, the bed nucleus of the stria terminalis, and the tail of the striatum, all brain regions critical for the regulation of emotions and motivated behaviors. Using a mouse model carrying a temporally controlled deletion of D2R in WFS1-neurons, we demonstrate that intact D2R signaling in this neuronal population is necessary to regulate homeostasis-dependent food-seeking behaviors in both male and female mice. In addition, we found that reduced D2R signaling in WFS1-neurons impaired active avoidance learning and innate escape responses. Collectively, these findings identify a yet undocumented role for D2R signaling in WFS1-neurons as a novel effector through which dopamine optimizes appetitive behaviors and regulates defensive behaviors.

Prefrontal circuits encode both general danger and specific threat representations.

Behavioral adaptation to potential threats requires both a global representation of danger to prepare the organism to react in a timely manner but also the identification of specific threatening situations to select the appropriate behavioral responses. The prefrontal cortex is known to control threat-related behaviors, yet it is unknown whether it encodes global defensive states and/or the identity of specific threatening encounters. Using a new behavioral paradigm that exposes mice to different threatening situations, we show that the dorsomedial prefrontal cortex (dmPFC) encodes a general representation of danger while simultaneously encoding a specific neuronal representation of each threat. Importantly, the global representation of danger persisted in error trials that instead lacked specific threat identity representations. Consistently, optogenetic prefrontal inhibition impaired overall behavioral performance and discrimination of different threatening situations without any bias toward active or passive behaviors. Together, these data indicate that the prefrontal cortex encodes both a global representation of danger and specific representations of threat identity to control the selection of defensive behaviors.

Novel Genetically Engineered Probiotics for Targeted Elimination of Pseudomonas aeruginosa in Intestinal Colonization.

The intestinal carriage rates of Pseudomonas aeruginosa are notably elevated in immunosuppressed individuals and hospitalized patients, increasing the risk of infection and antibiotic-associated diarrhea. A potential solution to this issue lies in autonomous antibacterial therapy, remaining inactive until a pathogen is detected, and releasing antibacterial compounds on demand to eliminate the pathogen. This study focuses on the development of genetically engineered probiotics capable of detecting and eradicating P. aeruginosa by producing and secreting PA2-GNU7, a P. aeruginosa-selective antimicrobial peptide (AMP), triggered by the presence of P. aeruginosa quorum-sensing molecule N-(3-oxododecanoyl)-L-homoserine lactone (3OC12HSL). To achieve this goal, plasmid-based systems were constructed to produce AMPs in response to 3OC12HSL and secrete them into the extracellular medium using either the microcin V secretion system or YebF as a carrier protein. Following the transfer of these plasmid-based systems to Escherichia coli Nissle 1917 (EcN), we successfully demonstrated the ability of the engineered EcN to express and secrete PA2-GNU7, leading to the inhibition of P. aeruginosa growth in vitro. In addition, in a mouse model of intestinal P. aeruginosa colonization, the administration of engineered EcN resulted in reduced levels of P. aeruginosa in both the feces and the colon. These findings suggest that engineered EcN holds promise as a potential option for combating intestinal P. aeruginosa colonization, thus mitigating the risk of future endogenous infections in vulnerable patients.

Interferon-γ enhances neocortical synaptic inhibition by promoting membrane association and phosphorylation of GABAA receptors in a protein kinase C-dependent manner.

Interferon-γ (IFN-γ), an important mediator of the antiviral immune response, can also act as a neuromodulator. CNS IFN-γ levels rise acutely in response to infection and therapeutically applied IFN-γ provokes CNS related side effects. Moreover, IFN-γ plays a key role in neurophysiological processes and a variety of chronic neurological and neuropsychiatric conditions. To close the gap between basic research, behavioral implications and clinical applicability, knowledge of the mechanism behind IFN-γ related changes in brain function is crucial. Here, we studied the underlying mechanism of acutely augmented neocortical inhibition by IFN-γ (1.000 IU ml-1) in layer 5 pyramidal neurons of male Wistar rats. We demonstrate postsynaptic mediation of IFN-γ augmented inhibition by pressure application of GABA and analysis of paired pulse ratios. IFN-γ increases membrane presence of GABAAR γ2, as quantified by cell surface biotinylation and functional synaptic GABAAR number, as determined by peak-scaled non-stationary noise analysis. The increase in functional receptor number was comparable to the increase in underlying miniature inhibitory postsynaptic current (mIPSC) amplitudes. Blockage of putative intracellular mediators, namely phosphoinositide 3-kinase and protein kinase C (PKC) by Wortmannin and Calphostin C, respectively, revealed PKC-dependency of the pro-inhibitory IFN-γ effect. This was corroborated by increased serine phosphorylation of P-serine PKC motifs on GABAAR γ2 upon IFN-γ application. GABAAR single channel conductance, intracellular chloride levels and GABAAR driving force are unlikely to contribute to the effect, as shown by single channel recordings and chloride imaging. The effect of IFN-γ on mIPSC amplitudes was similar in female and male rats, suggesting a gender-independent mechanism of action. Collectively, these results indicate a novel mechanism for the regulation of inhibition by IFN-γ, which could impact on neocortical function and therewith behavior.

Flapless implant surgery using a mini-incision.

BACKGROUND: Traditional flapless implant surgery using a soft tissue punch device requires a circumferential excision of keratinized tissue at the implant site. A new flapless implant technique that can submerge implant fixtures is needed. PURPOSE: This article describes a flapless implant surgery method using a mini-incision and compares the effects of soft tissue punch and mini-incision surgery on both the amount of osseointegration and the bone height around the implants using a canine mandible model. MATERIALS AND METHODS: Bilateral, edentulated, flat alveolar ridges were created in the mandibles of six mongrel dogs. After a 3-month healing period, two implants were placed on each side of the mandible using either soft tissue punch or mini-incision procedures. After an additional 3-month healing period, a second stage surgery and transmucosal abutment attachment was performed for mini-incision implant cases. Following a 2-month healing period, the dogs were sacrificed to evaluate the osseointegration and bone height around the implants. RESULTS: Average bone height was 9.6 ± 0.4 mm in the soft tissue punch group and 9.8 ± 0.3 mm in the mini-incision group (p > .05). Average osseointegration was 70.4 ± 6.3% in the soft tissue punch group and 71.2 ± 7.1% in the mini-incision group (p > .05). No significant differences were noted between the two groups in vertical alveolar ridge height or bone/implant contact. CONCLUSIONS: Our findings support the clinical use of mini-incision implant surgery at sites where implants need to be protected below the soft tissue during the early phase of healing, particularly for patients with poor bone quality and/or low primary implant stability.

Effects of flapless implant surgery on soft tissue profiles: a prospective clinical study.

BACKGROUND: Flapless implant surgery has been suggested as a suitable treatment modality for the preservation of soft tissue after implant placement. PURPOSE: The purpose of this study was to determine the extent of soft tissue profile changes around implants after flapless implant surgery. MATERIALS AND METHODS: A total of 44 patients received 76 implants using a flapless implant procedure. The marginal level of the peri-implant soft tissue was evaluated using dental casts 1 week, 1 month, and 4 months after implant placement. RESULTS: The mean soft tissue levels around implants showed 0.7 ± 0.3 mm of coronal growth 1 week after surgery. At 1 month, the levels were 0.2 ± 0.2 mm coronal growth and at 4 months, the values were 0.0 ± 0.3 mm. Soft tissue profiles assessed 4 months after flapless implant placement were similar to profiles assessed immediately before implant placement. CONCLUSION: Flapless implant surgery is advantageous for preserving mucosal form surrounding dental implants.

A comparative study on the extractions of partially impacted mandibular third molars with or without a buccal flap: a prospective study.

PURPOSE: The present report describes a flapless extraction method for partially impacted mandibular third molars and compares the effects of flap and flapless extractions of the teeth in terms of postoperative pain, swelling, and pocket depth of the second molar. PATIENTS AND METHODS: A prospective study was performed of 27 patients who underwent bilateral extraction of partially impacted mandibular third molars. Two molars in the same patient were extracted on each side, either with or without a buccal flap. RESULTS: The postoperative pain, swelling, and pocket depth of the second molar were all significantly greater on the side that underwent flap extraction than on the side that underwent flapless extraction (P < .05). CONCLUSIONS: Our results support the clinical use of flapless extractions when the distal surface of the crown is completely anterior to the anterior border of the mandibular ramus and the occlusal surface of the impacted tooth is level or nearly level with the occlusal plane of the second molar.

The use of autologous venous blood for maxillary sinus floor augmentation in conjunction with sinus membrane elevation: an experimental study.

BACKGROUND: There have been reports of successful bone formation with sinus floor elevation induced by simply elevating the maxillary sinus membrane and filling the sinus cavity with a blood clot. PURPOSE: We investigated the feasibility of maxillary sinus floor augmentation using the patient's own venous blood in conjunction with a sinus membrane elevation procedure. MATERIALS AND METHODS: An implant that protruded 8 mm into the maxillary sinus after sinus membrane elevation was placed in the maxillary sinus of six adult female mongrel dogs. The resulting space between the membrane and the sinus floor was filled with autologous venous blood retrieved from each dog. The implants were left in place for 6 months. RESULTS: During the experimental period, the created space collapsed and the sinus membrane fell down onto the implant. A small amount of new bone formation occurred in the space created by the collapsed membrane. The average height of newly formed bone around the implants in the sinus was 2.7+/-0.7 mm on the buccal side and 0.6+/-0.3 mm on the palatal side. CONCLUSION: The results of this pilot study indicate that blood clots do not have sufficient integrity to enable the sinus membrane to remain in an elevated position for therapeutically effective periods of time. Accordingly, it is recommended that this method be used only when a small amount of new bone formation is necessary around implants in the maxillary sinus cavity.

Effects of soft tissue punch size on the healing of peri-implant tissue in flapless implant surgery.

OBJECTIVE: In an attempt to help produce guidelines for the use of soft tissue punches, this animal study was undertaken to examine the effects of soft tissue punch size on the healing of peri-implant tissue in a canine mandible model. STUDY DESIGN: Bilateral, edentulous, flat alveolar ridges were created in the mandibles of 6 mongrel dogs. After a 3-month healing period, 3 fixtures (diameter 4.0 mm) were placed on each side of the mandible using 3-mm, 4-mm, or 5-mm soft tissue punches. After subsequent healing periods of 3 weeks and 3 months, the peri-implant mucosa was evaluated using clinical, radiologic, and histometric parameters, which included gingival index, bleeding on probing, probing pocket depth, marginal bone loss, and vertical dimension measurements of the peri-implant tissues. RESULTS: The results obtained showed significant differences (P < .05) between the 3-mm, 4-mm, and 5-mm tissue punch groups for the length of the junctional epithelium, probing depth, and marginal bone loss at both 3 weeks and 3 months after implant placement. When the mucosa was punched with a 3-mm tissue punch, the length of the junctional epithelium was shorter, the probing depth was shallower, and less crestal bone loss occurred than when using a tissue punch with a diameter >or=4 mm. CONCLUSIONS: The results show that the size of the soft tissue punch plays an important role in achieving optimal healing. The findings support the use of a tissue punch slightly narrower than the implant itself to obtain better peri-implant tissue healing around flapless implants.