Newly designed pyrrolo[2,1-c][1,4]benzodiazepines tricyclic skeleton has shown potential clusters of cannabinoid receptors CB1/CB2 selective ligands. CB2 plays a critical role in microglial-derived neuroinflammation, where it modulates cell proliferation, migration, and differentiation into M1 or M2 phenotypes. Beginning with computer-based docking studies accounting the recently discovered X-ray crystal structure of CB2, we designed a series of PBD analogs as potential ligands of CB2 and tested their binding affinities. Interestingly, computational studies and theoretical binding affinities of several selected (S,E)-11-[2-(arylmethylene)hydrazono]-PBD analogs, have revealed the presence of potential selectivity in binding attraction toward CB1 and CB2. Reported here is the discovery of the first representatives of this series of selective binding to CB2. Preliminary data showed that this class of molecules display potential binding efficacy toward the cannabinoid receptors tested. Intriguingly, initial cannabinoid binding assay showed a selective binding affinity of 4g and 4h showed Ki of 0.49 and 4.7 μM toward CB2 receptors while no binding was observed to CB1. The designed leads have shown remarkable stability pattern at the physiological pH magnifying their therapeutic values. We hypothesize that the PBD tricyclic structure offers the molecule an appropriate three-dimensional conformation to fit snugly within the active site of CB2 receptors, giving them superiority over the reported CB2 agonists/inverse agonists. Our findings suggested that the attachment of heterocyclic ring through the condensation of diazepine hydrazone and S- or N-heterocyclic aldehydes enhances the selectivity of CB2 over CB1. [Figure not available: see fulltext.].

Indiana University-Purdue University Indianapolis (IUPUI) / Damage Associated Molecular Patterns (DAMPs) act largely as endogenous ligands to initiate and maintain the signaling of both inflammatory processes and the acquired immune response. Prolonged action of these endogenous signals are thought to play a significant role sterile inflammation which may be integral to the development of chronic inflammation pathology. HMGB1 (High Mobility Group Box 1) is a highly conserved non-acetylated protein which is among the most important chromatin proteins and serves to organize DNA and regulate transcription. Following stress or injury to the cell, hyperacetylation of lysine residues causes translocation of HMGB1 and eventual release into the extracellular environment where it can take the form of a DAMP and interact with cell types bearing either the Receptor for Advanced Glycation End-products (RAGE) or Toll-Like Receptor 4 (TLR4). Activation of these surface receptors contribute directly to both acute and chronic inflammation. This project investigated the role of HMGB1 through its receptors Receptor for Advanced Glycation End-products (RAGE) and Toll-Like Receptor 4 (TLR4) as it pertained to the development of chronic inflammation and pathology in small diameter, nociceptive sensory neurons. It was demonstrated that the neuronal signaling associated with exposure to HMGB1 is dependent upon the ligands conformational states, as the state dictates its affinity and types of neuronal response. Neuronal activation by bacterial endotoxin or the disulfide state of HMGB1 is dependent on TLR4 and the associated signaling adapter protein, Myeloid differentiation primary response gene 88 (MYD88). Interruption of the receptor-mediated signaling cascade associated with MyD88 was shown to be sufficient to mitigate ligand-dependent neuronal activation and demonstrated significant behavioral findings. Further downstream signaling of HMGB1 in the neuron has yet to be identified, however important steps have been taken to elucidate the role of chronic neuroinflammation with hopes of eventual translational adaptation for clinical therapeutic modalities.

Major depressive disorder (MDD) is a leading cause of disability worldwide, with a lifetime prevalence rate of approximately 20%. Inadequate pharmacological treatment methods for MDD are a significant debilitating factor. Patient estimates suggest that the treatment resistance rate for pharmacological interventions is over 30%. Postmortem analyses of human tissue of individuals diagnosed with MDD have shown an increase in Poly (ADP-ribose) polymerase 1 (PARP-1) mRNA gene expression in prefrontal cortical white matter when compared to psychiatrically normal brain tissue. In order to further investigate this issue, the present study used the social defeat stress/chronic unpredictable stress (SDS + CUS) rodent model of depression to induce a state of chronic psychological distress. Rats were treated with either the PARP-inhibitor, 3-aminobenzamide (3-AB); a common selective serotonin reuptake inhibitor (SSRI) fluoxetine (FLX), or saline. During the stress manipulation we conducted the sucrose preference test, results revealed that saline-treated rats which had undergone SDS + CUS showed significant reductions in sucrose preference compared to all other groups. In addition, a social interaction test was conducted one day after the stress manipulation, and saline-treated stressed animals demonstrated less social interaction compared to all other groups, indicating the stress manipulation was effective. Neurobiological assays were conducted to examine PARP expression, microglial morphology, and proinflammatory cytokine expression. Though we expected to find a decrease, results from immunofluorescence studies of tissue sections revealed an elevation of PARP-1 protein expression in prefrontal cortical gray matter in the FLX/Stress group compared with SAL/Stress group. Microglial morphological changes indicated that the SAL/Stress group had significantly more prolate microglia when compared to all other treatment groups, suggesting early activation of microglia, an indicator of neuroinflammation. Increases in IL-1β and TNF-⍺ expression was observed in the hippocampus of the SAL/Stress group when compared to all other treatment groups. Interestingly, IL-6 expression was significantly elevated in the SAL/Stress group when compared to the FLX/Stress group and the CTRL/No stress group but did not significantly differ from the 3-AB/Stress group. This study revealed therapeutic potential of 3-AB for the treatment of stress-related disorders, as well as the neuroinflammatory mechanisms associated with chronic stress.

No description available.

Toxoplasma gondii infection is common in humans and is a significant risk factor for developing the disease schizophrenia. Genetic risk factors are likely required for the disease of schizophrenia to develop. Nurr1 – heterozygous (+/-) mice and wild-type (+/+) mice were evaluated using immune activation of astrocytes within the prefrontal cortex, dopamine levels within the striatum, and measuring the acoustic startle response reaction time by using prepulse inhibition (PPI). T. gondii infected heterozygous (+/-) mice exhibited increased GFAP expression within the prefrontal cortex. Dopamine levels within the striatum were measured and T. gondii infected wild-type (+/+) mice exhibited increased dopamine levels. The acoustic startle response reaction time was measured using PPI and T. gondii infected mice exhibited slower reaction times when compared to controls. These data demonstrate that the Nurr1 (+/-) genotype predisposes mice to T. gondii-induced alterations in behaviors that involve dopamine neurotransmission and are associated with symptoms of schizophrenia.

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Post-traumatic stress disorder (PTSD) is a debilitating disorder with a prevalence rate of approximately 5%. Unfortunately, this disorder is commonly associated with another debilitating disorder, alcohol use disorder (AUD). Of the 5% of people diagnosed with PTSD, 30%-59% also suffer from AUD. Currently, there are limited effective treatment options for those suffering from comorbid PTSD/AUD. Previous research has suggested that biological sex differentially impacts PTSD comorbid with AUD, however, the underlying mechanisms are enigmatic. The goal of this study was to better understand the underlying mechanisms that mediate sex differences in a rodent model of comorbid PTSD/AUD by analyzing specific behavioral tasks and changes in neuronal function of specific brain regions. Chronic inflammation has been implicated in PTSD and AUD respectively, with differences between sexes being observed. Females tend to express elevated levels of inflammation in both disorders compared to males in brain regions such as, the hippocampus, amygdala, and prefrontal cortex. Tumor necrosis factor α (TNF-α) is a proinflammatory cytokine that is released during neuronal inflammation. To further examine these sex differences, a comorbid PTSD/AUD rodent model was implemented using restraint stress (RS) and chronic intermittent ethanol use (CIE). Following the exposure to RS and CIE a fear conditioning procedure was implemented to assess changes in future stress sensitivity. The fear conditioning paradigm was accomplished by conditioning the animal to pair a tone with a foot shock, followed by extinction of that behavior in a different context where the animal received the tone but no foot shock. Thereafter, the animal was placed back in the context they received the foot shock, known as context renewal, but acquired no tone or foot shock. The behavior in these different contexts was analyzed to test memory and stress sensitivity. Brain tissue was collected to analyze TNF-α protein expression in regions associated with learning, memory, and addiction such as, the prelimbic cortex (PrL), infralimbic cortex (IfL), and the hippocampus. The results of the fear conditioning revealed that the females froze more altogether compared to the males, and there was more freezing of the females with RS and CIE during context renewal. It is expected that TNF-α protein expression will be significantly elevated in females when compared to males, regardless of treatment group. Females exposed to RS and CIE will have significantly higher TNF-α levels when compared to all other treatment groups. Finally, increases in TNF-α protein expression will be region specific with the PrL and IfL regions exhibiting significantly greater expression than the hippocampus. This study will aid in better understanding the sex differences and lead to better treatment options that are sex-dependent for those diagnosed with comorbid PTSD/AUD.

No description available.