Neurofilament heavy chain and chitinase 3-like 1 as markers for monitoring therapeutic response in multiple sclerosis.

AIMS: The aim of this study was to evaluate the association of serum neurofilament heavy chain (sNfH) and chitinase 3-like 1 (sCHI3L1) with treatment response and disease activity in multiple sclerosis (MS). METHODS: This single-center, prospective, observational cohort study was conducted at the MS Centre, University Hospital Ostrava, Czech Republic, from May 2020 to August 2023. sNfH and sCHI3L1 were determined using ELISA. A mixed-effects linear model with a log-transformed outcome variable was applied. RESULTS: We analyzed 459 samples from 57 people with MS. Patients were sampled an average of 8.05 times during 21.9 months of follow-up. Those experiencing a relapse at sampling had a sNfH concentration 50 % higher than those in remission (exp(ß) 1.5, 95 % CI 1.15-1.96). A longer duration of treatment was associated with lower sNfH (exp(ß) 0.95, 95 % CI 0.94-0.96). Patients switched from low- to high-efficacy disease-modifying therapies (DMTs) had higher sNfH than patients treated with low-efficacy DMTs only (exp(ß) 1.95, 95 % CI 1.35-2.81). Higher sCHI3L1 was associated with older age (exp(ß) 1.01, 95 % CI 1.00-1.02) and longer DMT use (exp(ß) 1.01, 95 % CI 1.00-1.02). sCHI3L1 values were not associated with relapse at the time of sampling, renal function, sex, or type of DMT. CONCLUSION: In contrast to sCHI3L1, sNfH may be a potential biomarker for monitoring treatment response and confirming clinical relapse in MS. Further research is needed to determine the long-term dynamics of sNfH and develop related treatment strategies.

Orthopedic Skin Closure in South India: Sutures Versus Staples and Their Postoperative Outcomes.

Introduction Skin closure is an essential step in deciding the success of a surgery. Despite this, the choice of skin closure material is frequently overlooked when making surgical decisions. Skin closure plays an important role in promoting rapid wound healing and decreasing the length of hospital stay, especially in orthopedic surgeries. Our study focused on comparing the outcome of wound closure in orthopedic surgeries with sutures and staples in a South Indian population. Materials and methods We enrolled 120 patients undergoing orthopedic procedures at Chettinad Hospital and Research Institute from July 2023 to February 2024. Patients were randomly assigned to skin closure with either staples or sutures. Wound inspection was done on the 2nd, 5th, 7th and 12th post-operative days. The patients were evaluated at six months using the Visual Analog Scale (VAS) and Hollander Wound Evaluation Score (HWES). Results Staple closure significantly reduced mean closure time (5.2 ± 0.9 minutes) compared to sutures (12.6 ± 1.5 minutes, p < 0.0001). Pain during staple removal was less (VAS score 1.41 ± 0.15) than with suture removal (VAS score 1.57 ± 0.2, p = 0.024). Although patient satisfaction was similar between the groups (Staples: 8.35 ± 0.45 vs. Sutures: 8.0 ± 0.5, p = 0.062), staples provided superior cosmetic outcomes (HWES: 4.1 ± 0.7) compared to sutures (HWES: 3.3 ± 0.6, p = 0.003). Complication rates, including infection, discharge, and hypertrophic scar formation, were comparable between the two methods. Conclusion Staple closure in orthopedic surgeries offers several advantages over sutures, including reduced operative time, less pain during removal, and superior cosmetic results. These benefits occur without an increased risk of wound complications. This study suggests that staples may be a preferable option for skin closure in orthopedic procedures, though further research with extended follow-up is needed to fully assess long-term outcomes.

Understanding physician preferences about combined thrombolysis and thrombectomy in patients with large vessel occlusion: An international cross-sectional survey.

BACKGROUND: A recently published individual participant-level meta-analysis found that EVT alone was not non-inferior to combined intravenous thrombolysis (IVT) and EVT. Our aim was to determine factors that influence physicians' treatment choice of IVT-alone versus EVT-alone versus a combined approach. METHODS: We performed an international, structured, invite-only survey among physicians treating patients presenting with AIS. Respondents were asked 16 multiple choice questions. Fourteen questions involved the respondent being provided with a clinical scenario. In each scenario, a patient was presenting with an AIS with LVO, varying a single clinical or imaging feature. RESULTS: A total of 282 stroke physicians (mean age 46 years, 75 % males) participated in the survey. In LVO stroke, eligible for both IVT and EVT, without other qualifiers, 220 (85.9 %) respondents chose to pursue a combined approach. For age over 80 years, 191 (74 %) participants opted for combined approach, which decreased to 121 (48.2 %) with dementia and 148 (57.4 %) if the patient was on dual anti-platelet therapy (DAPT). Of respondents choosing combination therapy in a patient above the age of 80, only 105 (56.8 %) would pursue the same in a patient with dementia. For imaging factors, 177 (72.8 %) opted for a combined approach for intracranial carotid occlusion, which decreased to 160 (65.3 %) in tandem occlusions. Overall, 88 (38 %) respondents agreed to the statement "I am uncomfortable with uncertainty in patient care". CONCLUSIONS: In a typical patient with AIS due to LVO, most respondents still choose a combined revascularization approach but discrepancy in decision-making increases in complex scenarios.

Negative allosteric modulation of CB1 cannabinoid receptor signalling decreases intravenous morphine self-administration and relapse in mice.

The endocannabinoid system interacts with the reward system to modulate responsiveness to natural reinforcers, as well as drugs of abuse. Previous preclinical studies suggested that direct blockade of CB1 cannabinoid receptors (CB1R) could be leveraged as a potential pharmacological approach to treat substance use disorder, but this strategy failed during clinical trials due to severe psychiatric side effects. Alternative strategies have emerged to circumvent the side effects of direct CB1 binding through the development of allosteric modulators. We hypothesized that negative allosteric modulation of CB1R signalling would reduce the reinforcing properties of morphine and decrease behaviours associated with opioid misuse. By employing intravenous self-administration in mice, we studied the effects of GAT358, a functionally-biased CB1R negative allosteric modulator (NAM), on morphine intake, relapse-like behaviour and motivation to work for morphine infusions. GAT358 reduced morphine infusion intake during the maintenance phase of morphine self-administration under a fixed ratio 1 schedule of reinforcement. GAT358 also decreased morphine-seeking behaviour after forced abstinence. Moreover, GAT358 dose dependently decreased the motivation to obtain morphine infusions under a progressive ratio schedule of reinforcement. Strikingly, GAT358 did not affect the motivation to work for food rewards in an identical progressive ratio task, suggesting that the effect of GAT358 in decreasing opioid self-administration was reward specific. Furthermore, GAT58 did not produce motor ataxia in the rotarod test. Our results suggest that CB1R NAMs reduced the reinforcing properties of morphine and could represent a viable therapeutic route to safely decrease misuse of opioids.

Negative allosteric modulation of CB1 cannabinoid receptor signaling suppresses opioid-mediated tolerance and withdrawal without blocking opioid antinociception.

The direct blockade of CB1 cannabinoid receptors produces therapeutic effects as well as adverse side-effects that limit their clinical potential. CB1 negative allosteric modulators (NAMs) represent an indirect approach to decrease the affinity and/or efficacy of orthosteric cannabinoid ligands or endocannabinoids at CB1. We recently reported that GAT358, a CB1-NAM, blocked opioid-induced mesocorticolimbic dopamine release and reward via a CB1-allosteric mechanism of action. Whether a CB1-NAM dampens opioid-mediated therapeutic effects such as analgesia or alters other unwanted opioid side-effects remain unknown. Here, we characterized the effects of GAT358 on nociceptive behaviors in the presence and absence of morphine in male rats. We examined the impact of GAT358 on formalin-evoked pain behavior and Fos protein expression, a marker of neuronal activation, in the lumbar spinal cord. We also assessed the impact of GAT358 on morphine-induced slowing of colonic transit, tolerance, and withdrawal behaviors in male mice. GAT358 attenuated morphine antinociceptive tolerance without blocking acute antinociception and reduced morphine-induced slowing of colonic motility without impacting fecal boli production. GAT358 also produced antinociception in the presence and absence of morphine in the formalin model of inflammatory nociception and reduced the number of formalin-evoked Fos protein-like immunoreactive cells in the lumbar spinal cord. Finally, GAT358 mitigated the somatic signs of naloxone-precipitated, but not spontaneous, opioid withdrawal following chronic morphine dosing. Our results support the therapeutic potential of CB1-NAMs as novel drug candidates aimed at preserving opioid-mediated analgesia while preventing their unwanted side-effects. Our studies also uncover previously unrecognized antinociceptive properties associated with an arrestin-biased CB1-NAM.

Association of parent-reported timing of first tooth emergence and ECC: a secondary analysis of a case-control study.

PURPOSE: Tooth eruption is a dynamic process. Appearance of any part of the cusp through gingiva may be a clinical marker of eruption. Early childhood caries (ECC) is a public health problem globally. This study aimed to assess the relationship between parent-reported timing of first tooth emergence and ECC in toddlers. METHODS: This study is a secondary data analysis of 627 toddlers involved in a case-control study on sleep-time feeding practises in children. The children were categorised into four groups based on the parent-reported timing of first primary tooth emergence (G1-when the first primary tooth emerged before 6 months of age, G2-between 7 and 9 months; G3-10 to 12 months and G4-when the first primary tooth emerged after 12 months of age). Univariate binary logistic regression analysis was performed to evaluate the association between timing of first tooth emergence and ECC. RESULTS: The mean age of the children was 24.4 ± 7.3 months (cases, that is children with ECC-25.4 ± 6.9 months, controls, that is children without ECC-23.6 ± 7.5 months). Of 60 children, whose first tooth erupted before 6 months of age, 35 (12%) were cases compared to 25(8%) controls. Amongst the cases, boys had more caries than girls (p < 0.05). Of the anterior teeth, 22% of the emerged teeth were decayed in the first group, followed by 19%, 16% and 10% in the second, third and fourth groups, respectively (p < 0.05). Analysis of the posterior teeth showed a lower percentage of decayed teeth with delayed emergence of the first primary tooth (p < 0.05). Children whose teeth emerged before 6 months of age had an odds ratio of 3.5 (95% CI 1.49, 8.42) (p = 0.004). CONCLUSION: This study concluded that the early emergence of the first primary tooth, as reported by the parent, was associated with an increased risk of developing ECC.

Explorations of Agonist Selectivity for the α9* nAChR with Novel Substituted Carbamoyl/Amido/Heteroaryl Dialkylpiperazinium Salts and Their Therapeutic Implications in Pain and Inflammation.

There is an urgent need for nonopioid treatments for chronic and neuropathic pain to provide effective alternatives amid the escalating opioid crisis. This study introduces novel compounds targeting the α9 nicotinic acetylcholine receptor (nAChR) subunit, which is crucial for pain regulation, inflammation, and inner ear functions. Specifically, it identifies novel substituted carbamoyl/amido/heteroaryl dialkylpiperazinium iodides as potent agonists selective for human α9 and α9α10 over α7 nAChRs, particularly compounds 3f, 3h, and 3j. Compound 3h (GAT2711) demonstrated a 230 nM potency as a full agonist at α9 nAChRs, being 340-fold selective over α7. Compound 3c was 10-fold selective for α9α10 over α9 nAChR. Compounds 2, 3f, and 3h inhibited ATP-induced interleukin-1ß release in THP-1 cells. The analgesic activity of 3h was fully retained in α7 knockout mice, suggesting that analgesic effects were potentially mediated through α9* nAChRs. Our findings provide a blueprint for developing α9*-specific therapeutics for pain.

Key lessons from the establishment of a nurse-led infection prevention and control program for COVID-19 in an Australian hotel quarantine and isolation service.

BACKGROUND: A key aspect of Australia's response to the COVID-19 pandemic was to control transmission through legislated quarantine and isolation of overseas returning travellers and potentially infectious community members. In New South Wales, Special Health Accommodation (SHA) was rapidly established as a comprehensive health service for individuals that were at risk of having COVID-19, were confirmed to have COVID-19 or for those with complex health needs that were deemed inappropriate for management in Police managed Quarantine Hotels. SHA services were later expanded to care for community members who were COVID-19 positive and unable to effectively isolate, or contacts of individuals who were unable to quarantine effectively in their homes. SHA's unique nurse-led Infection Prevention and Control (IPC) program offers key lessons that may impact future programs. METHODS: A reflection on the experience of leading an Infection Prevention and Control program in SHA was undertaken. This was supported by a review of SHA admission, workforce and transmission data and data obtained from a cross-sectional questionnaire aimed to better understand the experiences of a novel population of health workers (HW) in a comprehensive health-led quarantine and isolation service. RESULTS: SHA program data demonstrates how its IPC program implementation prevented transmission of COVID-19 to SHA staff and patients. Responses from the questionnaire suggested staff felt safe and well-prepared through the IPC education they received. They also gained transferrable knowledge and skills, which they intend to use in future healthcare roles. CONCLUSION: The SHA nurse-led IPC program offered successful quarantine and isolation for COVID-19 in non-purpose-built facilities. A review of IPC strategies and key lessons from the establishment of the SHA IPC program are of critical importance to planning and management of current and future pandemics.

Unusual Presentation of Synovial Lipomatosis Mimicking As Septic Arthritis of Knee: A Case Report.

Synovial lipomatosis or lipoma arborescens is a very uncommon pseudo-tumorous lesion of the synovium which more commonly affects the knee joint. The most probable cause of this pathological lesion is degenerative articular disorders of the joint and improper fat accumulation. It is characterized by presence of villous proliferation of the synovium and replacement of the sub-synovial tissue by mature adipocytes which is infiltrated by dense chronic inflammatory cells like lymphocytes, plasma cells and eosinophils. This condition is rarely seen in smaller joints. Its aetiology is still unknown. We report a patient who presented with features of septic arthritis which on intraoperative and histopathological assessment showed features of synovial lipomatosis.

New Alpha9 nAChR Ligands Based on a 5-(Quinuclidin-3-ylmethyl)-1,2,4-oxadiazole Scaffold.

Several lines of evidence have indicated that nicotinic acetylcholine receptors (nAChR) that contain α9 subunits, probably in combination with α10 subunits, may be valuable targets for the management of pain associated with inflammatory diseases through a cholinergic anti-inflammatory system (CAS), which has also been associated with α7 nAChR. Both α7- and α9-containing neuronal nAChR can be pharmacologically distinguished from the high-affinity nicotinic receptors of the brain by their sensitivity to α-bungarotoxin, but in other ways, they have quite distinct pharmacological profiles. The early association of α7 with CAS led to the development of numerous new ligands, variously characterized as α7 agonists, partial agonists, or silent agonists that desensitized α7 receptors without activation. Subsequent reinvestigation of one such family of α7 ligands based on an N,N-diethyl-N'-phenylpiperazine scaffold led to the identification of potent agonists and antagonists for α9. In this paper, we characterize the α9/α10 activity of a series of compounds based on a 5-(quinuclidin-3-ylmethyl)-1,2,4-oxadiazole (QMO) scaffold and identify two new potent ligands of α9, QMO-28, an agonist, and QMO-17, an antagonist. We separated the stereoisomers of these compounds to identify the most potent agonist and discovered that only the 3R isomer of QMO-17 was an α9 antagonist, permitting an in silico model of α9 antagonism to be developed. The α9 activity of these compounds was confirmed to be potentially useful for CAS management of inflammatory pain in cell-based assays of cytokine release.

Structural mechanisms of α7 nicotinic receptor allosteric modulation and activation.

The α7 nicotinic acetylcholine receptor is a pentameric ligand-gated ion channel that plays an important role in cholinergic signaling throughout the nervous system. Its unique physiological characteristics and implications in neurological disorders and inflammation make it a promising but challenging therapeutic target. Positive allosteric modulators overcome limitations of traditional α7 agonists, but their potentiation mechanisms remain unclear. Here, we present high-resolution structures of α7-modulator complexes, revealing partially overlapping binding sites but varying conformational states. Structure-guided functional and computational tests suggest that differences in modulator activity arise from the stable rotation of a channel gating residue out of the pore. We extend the study using a time-resolved cryoelectron microscopy (cryo-EM) approach to reveal asymmetric state transitions for this homomeric channel and also find that a modulator with allosteric agonist activity exploits a distinct channel-gating mechanism. These results define mechanisms of α7 allosteric modulation and activation with implications across the pentameric receptor superfamily.

Negative allosteric modulation of CB1 cannabinoid receptor signaling decreases intravenous morphine self-administration and relapse in mice.

The endocannabinoid system interacts with the reward system to modulate responsiveness to natural reinforcers, as well as drugs of abuse. Previous preclinical studies suggested that direct blockade of CB1 cannabinoid receptors (CB1R) could be leveraged as a potential pharmacological approach to treat substance use disorder, but this strategy failed during clinical trials due to severe psychiatric side effects. Alternative strategies have emerged to circumvent the side effects of direct CB1 binding through the development of allosteric modulators. We hypothesized that pharmacological inhibition of CB1R signaling through negative allosteric modulation (NAM) would reduce the reinforcing properties of morphine and decrease opioid addictive behaviors. By employing i.v. self-administration in mice, we studied the effects of the CB1-biased NAM GAT358 on morphine intake, relapse-like behavior, and motivation to work for morphine infusions. Our data revealed that GAT358 reduced morphine infusion intake during the maintenance phase of morphine self-administration under fixed ratio 1 schedule of reinforcement. GAT358 decreased morphine-seeking behavior after forced abstinence. Moreover, GAT358 dose-dependently decreased the motivation to obtain morphine infusions in a progressive ratio schedule of reinforcement. Strikingly, GAT358 did not affect the motivation to work for food rewards in an identical progressive ratio task, suggesting that the effect of GAT358 in decreasing opioid self-administration is reward specific. Furthermore, GAT58 did not produce motor ataxia in the rota-rod test. Our results suggest that CB1R NAMs reduced the reinforcing properties of morphine and could represent a viable therapeutic route to safely decrease opioid-addicted behaviors.

Negative allosteric modulation of cannabinoid CB 1 receptor signaling suppresses opioid-mediated tolerance and withdrawal without blocking opioid antinociception.

The direct blockade of CB 1 cannabinoid receptors produces therapeutic effects as well as adverse side-effects that limit their clinical potential. CB 1 negative allosteric modulators (NAMs) represent an indirect approach to decrease the affinity and/or efficacy of orthosteric cannabinoid ligands or endocannabinoids at CB 1 . We recently reported that GAT358, a CB 1 -NAM, blocked opioid-induced mesocorticolimbic dopamine release and reward via a CB 1 -allosteric mechanism of action. Whether a CB 1 -NAM dampens opioid-mediated therapeutic effects such as analgesia or alters other unwanted side-effects of opioids remain unknown. Here, we characterized the effects of GAT358 on nociceptive behaviors in the presence and absence of morphine. We examined the impact of GAT358 on formalin-evoked pain behavior and Fos protein expression, a marker of neuronal activation, in the lumbar dorsal horn. We also assessed the impact of GAT358 on morphine-induced slowing of colonic transit, tolerance, and withdrawal behaviors. GAT358 attenuated morphine antinociceptive tolerance without blocking acute antinociception. GAT358 also reduced morphine-induced slowing of colonic motility without impacting fecal boli production. GAT358 produced antinociception in the presence and absence of morphine in the formalin model of inflammatory nociception and reduced the number of formalin-evoked Fos protein-like immunoreactive cells in the lumbar spinal dorsal horn. Finally, GAT358 mitigated the somatic signs of naloxone-precipitated, but not spontaneous, opioid withdrawal following chronic morphine dosing in mice. Our results support the therapeutic potential of CB 1 -NAMs as novel drug candidates aimed at preserving opioid-mediated analgesia while preventing their unwanted side-effects. Our studies also uncover previously unrecognized antinociceptive properties associated with an arrestin-biased CB 1 -NAMs. Highlights: CB 1 negative allosteric modulator (NAM) GAT358 attenuated morphine tolerance GAT358 reduced morphine-induced slowing of colonic motility but not fecal productionGAT358 was antinociceptive for formalin pain alone and when combined with morphineGAT358 reduced formalin-evoked Fos protein expression in the lumbar spinal cordGAT358 mitigated naloxone precipitated withdrawal after chronic morphine dosing.

Development and validation of a questionnaire to assess commonality knowledge of traumatic dental injuries and management of emergencies.

BACKGROUND: Dental trauma represents a significant public health problem, causing a burden for both individuals and society. The aim of this study is to systematically develop and validate a questionnaire on 'traumatic dental injuries and management of emergencies' (TIME) for assessing the knowledge, attitude and practice (KAP) for a commonality. METHODS: The scale development phases included conceptual framework, systematic development of an item pool, refinement of the item pool by Focus-group discussion (n = 23), validity-testing using Content Validity Index (n = 5), translation and back-translation, Cognitive interviewing (n = 30,45), and reliability testing (n = 40). The conceptual framework was built based on six broad constructs, such as broken teeth, knocked-out (avulsion) teeth, pushed/moved-in and loosened teeth (luxation injuries), soft tissue injuries, follow-up and management, and prevention and protection. RESULTS: Reviews of existing questionnaires significantly helped to generate an initial pool of 68 items (refined to 51 items). Lawshe's content validity was 0.92. High test-retest reliability was demonstrated (kappa value = 0.98). The questionnaire showed a high level of reliability (Cronbach's alpha = 0.86) with great internal consistency. CONCLUSION: TIME is the first validated scale for recording knowledge, attitude and practices on traumatic dental injuries and management of emergencies for non-dental professionals. The 51-tem tool will allow dentists to evaluate KAP of commonality. KAP measured across the globe would have a significant impact on planning awareness programs by dentists and dental associations.

Modulating the dynamics of NFκB and PI3K enhances the ensemble-level TNFR1 signaling mediated apoptotic response.

Cell-to-cell variability during TNFα stimulated Tumor Necrosis Factor Receptor 1 (TNFR1) signaling can lead to single-cell level pro-survival and apoptotic responses. This variability stems from the heterogeneity in signal flow through intracellular signaling entities that regulate the balance between these two phenotypes. Using systematic Boolean dynamic modeling of a TNFR1 signaling network, we demonstrate that the signal flow path variability can be modulated to enable cells favour apoptosis. We developed a computationally efficient approach "Boolean Modeling based Prediction of Steady-state probability of Phenotype Reachability (BM-ProSPR)" to accurately predict the network's ability to settle into different phenotypes. Model analysis juxtaposed with the experimental observations revealed that NFκB and PI3K transient responses guide the XIAP behaviour to coordinate the crucial dynamic cross-talk between the pro-survival and apoptotic arms at the single-cell level. Model predicted the experimental observations that ~31% apoptosis increase can be achieved by arresting Comp1 - IKK* activity which regulates the NFκB and PI3K dynamics. Arresting Comp1 - IKK* activity causes signal flow path re-wiring towards apoptosis without significantly compromising NFκB levels, which govern adequate cell survival. Priming an ensemble of cancerous cells with inhibitors targeting the specific interaction involving Comp1 and IKK* prior to TNFα exposure could enable driving them towards apoptosis.

Development of alkali activated paver blocks for medium traffic conditions using industrial wastes and prediction of compressive strength using random forest algorithm.

Geopolymer is an environment friendly construction material that could be synthesized using either the natural source or the industrial byproducts such as flyash and GGBS. The characteristics of the Geopolymer rely on the proportion of the flyash and GGBS and the concentration of the activator solution used. In this research work, the effect of partial replacement of flyash with GGBS in proportions such as 0, 10, 20, 30 and 40% is investigated. Also Molarity of NaOH are tested from 8 to 14 M and both the parameters are optimized. In this optimized Geopolymer concrete, the utilization of iron slag as a partial substitute for river sand in various proportions such as 10, 15, 20, 25, 30 35, 40 and 45% are investigated. The optimized Geopolymer concrete with iron slag is investigated for its performance as a paver block with incorporation of banana fiber in proportions such as 0, 0.5, 1 and 1.5 and is compared with conventional cement concrete paver block. The results show that there is a significant enhancement in the properties of Geopolymer concrete with the different levels of optimization and the utilization of natural banana fiber. The developed sustainable paver block was found to with stand medium traffic conditions as per IS 15658:2006. Further this study employed random forest (RF) algorithm for the prediction of compressive strength of geopolymer concrete specimens for the variable parameters such as molarity of alkaline solution, Flyash/GGBS ratio and partial replacement of river sand with iron slag. The performance evaluation parameters represented high accuracy of developed RF model. This research work unleashes a heft potential of Geopolymer concrete to develop economical eco-friendly sustainable paver blocks to the society through mitigation of environmental strain on the ecosystem.

Dose-dependent effects of GAT107, a novel allosteric agonist-positive allosteric modulator (ago-PAM) for the α7 nicotinic cholinergic receptor: a BOLD phMRI and connectivity study on awake rats.

Background: Alpha 7 nicotinic acetylcholine receptor (α7nAChR) agonists have been developed to treat schizophrenia but failed in clinical trials due to rapid desensitization. GAT107, a type 2 allosteric agonist-positive allosteric modulator (ago-PAM) to the α7 nAChR was designed to activate the α7 nAChR while reducing desensitization. We hypothesized GAT107 would alter the activity of thalamocortical neural circuitry associated with cognition, emotion, and sensory perception. Methods: The present study used pharmacological magnetic resonance imaging (phMRI) to evaluate the dose-dependent effect of GAT107 on brain activity in awake male rats. Rats were given a vehicle or one of three different doses of GAT107 (1, 3, and 10 mg/kg) during a 35 min scanning session. Changes in BOLD signal and resting state functional connectivity were evaluated and analyzed using a rat 3D MRI atlas with 173 brain areas. Results: GAT107 presented with an inverted-U dose response curve with the 3 mg/kg dose having the greatest effect on the positive BOLD volume of activation. The primary somatosensory cortex, prefrontal cortex, thalamus, and basal ganglia, particularly areas with efferent connections from the midbrain dopaminergic system were activated as compared to vehicle. The hippocampus, hypothalamus, amygdala, brainstem, and cerebellum showed little activation. Forty-five min post treatment with GAT107, data for resting state functional connectivity were acquired and showed a global decrease in connectivity as compared to vehicle. Discussion: GAT107 activated specific brain regions involved in cognitive control, motivation, and sensory perception using a BOLD provocation imaging protocol. However, when analyzed for resting state functional connectivity there was an inexplicable, general decrease in connectivity across all brain areas.

GAT107-mediated α7 nicotinic acetylcholine receptor signaling attenuates inflammatory lung injury and mortality in a mouse model of ventilator-associated pneumonia by alleviating macrophage mitochondrial oxidative stress via reducing MnSOD-S-glutathionylation.

Supraphysiological concentrations of oxygen (hyperoxia) can compromise host defense and increase susceptibility to bacterial and viral infections, causing ventilator-associated pneumonia (VAP). Compromised host defense and inflammatory lung injury are mediated, in part, by high extracellular concentrations of HMGB1, which can be decreased by GTS-21, a partial agonist of α7 nicotinic acetylcholine receptor (α7nAChR). Here, we report that a novel α7nAChR agonistic positive allosteric modulator (ago-PAM), GAT107, at 3.3 mg/kg, i.p., significantly decreased animal mortality and markers of inflammatory injury in mice exposed to hyperoxia and subsequently infected with Pseudomonas aeruginosa. The incubation of macrophages with 3.3 µM of GAT107 significantly decreased hyperoxia-induced extracellular HMGB1 accumulation and HMGB1-induced macrophage phagocytic dysfunction. Hyperoxia-compromised macrophage function was correlated with impaired mitochondrial membrane integrity, increased superoxide levels, and decreased manganese superoxide dismutase (MnSOD) activity. This compromised MnSOD activity is due to a significant increase in its level of glutathionylation. The incubation of hyperoxic macrophages with 3.3 µM of GAT107 significantly decreases the levels of glutathionylated MnSOD, and restores MnSOD activity and mitochondrial membrane integrity. Thus, GAT107 restored hyperoxia-compromised phagocytic functions by decreasing HMGB1 release, most likely via a mitochondrial-directed pathway. Overall, our results suggest that GAT107 may be a potential treatment to decrease acute inflammatory lung injury by increasing host defense in patients with VAP.

Ccn2a-FGFR1-SHH signaling is necessary for intervertebral disc homeostasis and regeneration in adult zebrafish.

Intervertebral disc (IVD) degeneration is the primary cause of back pain in humans. However, the cellular and molecular pathogenesis of IVD degeneration is poorly understood. This study shows that zebrafish IVDs possess distinct and non-overlapping zones of cell proliferation and cell death. We find that, in zebrafish, cellular communication network factor 2a (ccn2a) is expressed in notochord and IVDs. Although IVD development appears normal in ccn2a mutants, the adult mutant IVDs exhibit decreased cell proliferation and increased cell death leading to IVD degeneration. Moreover, Ccn2a overexpression promotes regeneration through accelerating cell proliferation and suppressing cell death in wild-type aged IVDs. Mechanistically, Ccn2a maintains IVD homeostasis and promotes IVD regeneration by enhancing outer annulus fibrosus cell proliferation and suppressing nucleus pulposus cell death through augmenting FGFR1-SHH signaling. These findings reveal that Ccn2a plays a central role in IVD homeostasis and regeneration, which could be exploited for therapeutic intervention in degenerated human discs.