COX1 and COX2 expression in non-neuronal cellular compartments of the rhesus macaque brain during lentiviral infection

Review of triazole scaffolds for treatment and diagnosis of Alzheimer's disease

Triazole scaffolds, a series of 5-membered heterocycles, are well known for their high efficacy, low toxicity, and superior pharmacokinetics. Alzheimer's disease (AD) is the first neurodegenerative disorder with complex pathological mechanisms. Triazole, as an aromatic group with three nitrogen atoms, forms polar and non-polar interactions with diverse key residues in the receptor-ligand binding procedure, and has been widely used in the molecular design in the development of anti-AD agents. Moreover, considering the simple synthesis approaches, triazole scaffolds are commonly used to link two pharmacodynamic groups in one chemical molecule, forming multi-target directed ligands (MTDLs). Furthermore, the click reaction between azide- and cyano-modified enzyme and ligand provides feasibility for the new modulator discovery, compound tissue distribution evaluation, enzyme localization, and pharmacological mechanism study, promoting the diagnosis of AD course.

Serum COX-2 and FOXO3a in patients with rheumatoid arthritis and correlation with disease activity

Expression levels of serum cyclooxygenase (COX)-2 and forkhead box O3a (FOXO3a) in patients with rheumatoid arthritis (RA) and the correlation with disease activity were investigated. Sixty patients with RA admitted to the People's Hospital of Guangxi Zhuang Autonomous Region (study group; 28 active patients and 32 remissive patients), and further 30 healthy subjects undergoing physical examinations during the same period (control group) were enrolled in this study. RT-qPCR and enzyme-linked immunosorbent assay (ELISA) were used to detect the expression levels of COX-2 and FOXO3a in serum. According to DAS28 score, the patients were divided into active and remissive patients, between whom the expression levels were compared. Receiver operating characteristic (ROC) curves were plotted to analyze the diagnostic values of COX-2 and FOXO3a for disease activity. Pearson's correlation coefficient was used to analyze the correlation of the two markers with erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and DAS28 score. The expression levels of COX-2 and FOXO3a in active and remissive patients were significantly higher than those in the control group (both P<0.05), and those in active patients were significantly higher than those in remissive patients (both P<0.05). The areas under the ROC curves (AUCs) of COX-2 and FOXO3a were 0.748 and 0.802, respectively, suggesting that the two markers have high diagnostic value. The expression levels of COX-2 and FOXO3a were positively correlated with ESR, CRP, and DAS28 score of active and remissive patients (both P<0.05). In conclusion, the expression levels of COX-2 and FOXO3a in patients with RA are upregulated, thus, the two markers may be involved in the development and progression of the disease. The expression levels of COX-2 and FOXO3a are related to the disease activity of RA, and therefore can be used as diagnostic indicators for the disease activity.

First-in-human evaluation of [11C]PS13, a novel PET radioligand, to quantify cyclooxygenase-1 in the brain

PURPOSE

This study assessed whether the newly developed PET radioligand [¹¹C]PS13, which has shown excellent in vivo selectivity in previous animal studies, could be used to quantify constitutive levels of cyclooxygenase-1 (COX-1) in healthy human brain.

METHODS

Brain test-retest scans with concurrent arterial blood samples were obtained in 10 healthy individuals. The one- and unconstrained two-tissue compartment models, as well as the Logan graphical analysis were compared, and test-retest reliability and time-stability of total distribution volume (V_T) were assessed. Correlation analyses were conducted between brain regional V_T and COX-1 transcript levels provided in the Allen Human Brain Atlas.

RESULTS

In the brain, [¹¹C]PS13 showed highest uptake in the hippocampus and occipital cortex. The pericentral cortex also showed relatively higher uptake compared with adjacent neocortices. The two-tissue compartment model showed the best fit in all the brain regions, and the results from the Logan graphical analysis were consistent with those from the two-tissue compartment model. V_T values showed excellent test-retest variability (range 6.0-8.5%) and good reliability (intraclass correlation coefficient range 0.74-0.87). V_T values also showed excellent time-stability in all brain regions, confirming that there was no radiometabolite accumulation and that shorter scans were still able to reliably measure V_T. Significant correlation was observed between V_T and COX-1 transcript levels (r = 0.82, P = 0.007), indicating that [¹¹C]PS13 binding reflects actual COX-1 density in the human brain.

CONCLUSIONS

These results from the first-in-human evaluation of the ability of [¹¹C]PS13 to image COX-1 in the brain justifies extending the study to disease populations with neuroinflammation.

CLINICAL TRIAL REGISTRATION

NCT03324646 at https://clinicaltrials.gov/ . Registered October 30, 2017. Retrospectively registered.

3-Substituted 1,5-Diaryl-1 H-1,2,4-triazoles as Prospective PET Radioligands for Imaging Brain COX-1 in Monkey. Part 1: Synthesis and Pharmacology

Cyclooxygenase-1 (COX-1) is a key enzyme in the biosynthesis of proinflammatory thromboxanes and prostaglandins and is found in glial and neuronal cells within brain. COX-1 expression is implicated in numerous neuroinflammatory states. We aim to find a direct-acting positron emission tomography (PET) radioligand for imaging COX-1 in human brain as a potential biomarker of neuroinflammation and for serving as a tool in drug development. Seventeen 3-substituted 1,5-diaryl-1 H-1,2,4-triazoles were prepared as prospective COX-1 PET radioligands. From this set, three 1,5-(4-methoxyphenyl)-1 H-1,2,4-triazoles, carrying a 3-methoxy (5), 3-(1,1,1-trifluoroethoxy) (20), or 3-fluoromethoxy substituent (6), were selected for radioligand development, based mainly on their high affinities and selectivities for inhibiting human COX-1, absence of carboxyl group, moderate computed lipophilicities, and scope for radiolabeling with carbon-11 ( t_1/2 = 20.4 min) or fluorine-18 ( t_1/2 = 109.8 min). Methods were developed for producing [¹¹C]5, [¹¹C]20, and [ d₂-¹⁸F]6 from hydroxy precursors in a form ready for intravenous injection for prospective evaluation in monkey with PET.

Effect of Zishenpingchan granule prepared from Chinese medicinal substances on the c-Jun N-terminal protein kinase pathway in mice with Parkinson's disease induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine

OBJECTIVE

To investigate the regulatory mechanism of the c-Jun N-terminal protein kinase (JNK) signaling pathway in substantia nigra (SN) dopaminergic neurons inflammation and apoptosis, and the neuroprotective effect of Zishenpingchan granules in mice with Parkinson's disease (PD) induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP).

METHODS

PD model mice were established by intraperitoneally injecting MPTP. Sixty mice were divided into a model group, Traditional Chinese Medicine (TCM) group and control group. The mice of the TCM group were administered Zishenpingchan granules 7 days before PD induction. Seven days after PD induction, we examined locomotor activity, and performed the rotarod test and swimming test, to evaluate limb movement function. Furthermore, we used immunohistochemistry and western blotting to examine the expression of tyrosine hydroxylase (TH), cyclooxygenase-2 (Cox-2), caspase-3 and p-JNK. The terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) method was used to examine neuron apoptosis in the SN.

RESULTS

Compared with the control group, the mean score of locomotor activity, rotarod test and swimming test was significantly lower in the model group (P < 0.05); the TH-positive neuron expression was significantly decreased in the SN pars compacta (SNpc); the protein expression levels of Cox-2, caspase-3 and p-JNK was obviously increased; and the number of TUNEL-positive neurons in the SN was increased (P < 0.01). Compared with the model group, the mean score of neurobehavioral tests in the TCM group was obviously higher, the loss of TH-positive neurons ignificantly decreased, the protein expression levels of Cox-2, caspase-3 and p-JNK obviously decreased, and the number of TUNEL- positive neurons in the SN clearly decreased (P < 0.01).

CONCLUSION

The JNK pathway plays an important role in the regulation of inflammation and apoptosis in nigral cells in PD mice. TCM can suppress the over-activation of the JNK pathway in the SN, and alleviate the inflammatory response in nigral cells and dopaminergic neuron apoptosis in PD mice.

Cross-Coupling Effects of Silencing of Cyclooxygenase-2 (COX-2)/Aggrecanase-1 and Over-Expressed Insulin-Like Growth Factor 1 (IGF-1) in an Osteoarthritis Animal Model

BACKGROUND This study aimed to observe the effect of lentivirus-mediated cyclooxygenase-2 and aggrecanase-1 silencing and insulin-like growth factor-1 overexpression in human bone marrow mesenchymal stem cells after injection into model osteoarthritic knees. MATERIAL AND METHODS Using genetic recombination technique, the genes of cyclooxygenase-2, aggrecanase-1, and insulin-like growth factor-1 were recombined into the lentiviral vectors, and we transfected the human bone marrow stem cells in vitro. The BMSC transfected with lentivirus without genes served as a blank-virus group, and saline was used for another control group. One week later, the cytokines PGE2, aggrecanase-1, hIGF-1, and IL-1 were detected and compared between groups. RESULTS Compared with blank-virus group, the expression of COX-2 (85.81±5.12 ng/L) and aggrecanase1 (6.256±1.66) were decreased in the virus group (p<0.05), while the expression of hIGF-1 (17.46±1.86) was increased (p<0.05). The concentrations of PGE2 (85.81±5.12 ng/L), aggrecanase1 (51.34±5.463 ng/L), and IL-1 (82.31±4.321 ng/L) decreased (p<0.05) within the knee, but the concentration of hIGF-1 (44.33±0.7194 ng/L) increased (p<0.05). Compared with the other groups, the results of histological and immunohistochemical examinations demonstrated that the abrasion of articular cartilage was significantly improved and repaired. CONCLUSIONS Lentivirus-mediated RNAi can inhibit the expression of COX-2 mRNA and aggrecanase-1mRNA, and enhance the hIGF-1 mRNA expression, thereby influencing the concentration of cytokines in the early osteoarthritic model knee joints.

Attenuated SIV causes persisting neuroinflammation in the absence of a chronic viral load and neurotoxic antiretroviral therapy

Using simian models, where SIV chronic viral loads are naturally controlled in the absence of potentially neurotoxic therapies, we investigated the neuropathological events occurring during times of suppressed viraemia and when these events were initiated.

Lentiviral infection of rhesus macaques causes long-term injury to cortical and hippocampal projections of prostaglandin-expressing cholinergic basal forebrain neurons

The simian immunodeficiency virus (SIV) macaque model resembles human immunodeficiency virus-acquired immunodeficiency syndrome (AIDS) and associated brain dysfunction. Altered expression of synaptic markers and transmitters in neuro-AIDS has been reported, but limited data exist for the cholinergic system and lipid mediators such as prostaglandins. Here, we analyzed cholinergic basal forebrain neurons with their telencephalic projections and the rate-limiting enzymes for prostaglandin synthesis, cyclooxygenase isotypes 1 and 2 (COX1 and COX2) in the brains of SIV-infected macaques with or without encephalitis and antiretroviral therapy and uninfected controls.Cyclooxygenase isotype 1, but not COX2, was coexpressed with markers of cholinergic phenotype, that is, choline acetyltransferase and vesicular acetylcholine transporter (VAChT), in basal forebrain neurons of monkey, as well as human, brain. Cyclooxygenase isotype 1 was decreased in basal forebrain neurons in macaques with AIDS versus uninfected and asymptomatic SIV-infected macaques. The VAChT-positive fiber density was reduced in frontal, parietal, and hippocampal-entorhinal cortex. Although brain SIV burden and associated COX1- and COX2-positive mononuclear and endothelial inflammatory reactions were mostly reversed in AIDS-diseased macaques that received 6-chloro-2',3'-dideoxyguanosine treatment, decreased VAChT-positive terminal density and reduced cholinergic COX1 expression were not. Thus, COX1 expression is a feature of primate cholinergic basal forebrain neurons; it may be functionally important and a critical biomarker of cholinergic dysregulation accompanying lentiviral encephalopathy. These results further imply that insufficiently prompt initiation of antiretroviral therapy in lentiviral infection may lead to neurostructurally unremarkable but neurochemically prominent irreversible brain damage.