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Purpose This study aimed to assess the activity of two phosphodiesterase (PDE) inhibitors, namely GRMS-55 and racemic lisofylline ((±)-LSF)) in vitro and in animal models of immune-mediated disorders. Methods Inhibition of human recombinant (hr)PDEs and TNF-alpha release from LPS-stimulated whole rat blood by the studied compounds were assessed in vitro. LPS-induced endotoxemia, concanavalin A (ConA)-induced hepatitis, and collagen-induced arthritis (CIA) animal models were used for in vivo evaluation. The potency of the investigated compounds was evaluated using PK/PD and PK/PD/disease progression modeling. Results GRMS-55 is a potent hrPDE7A and hrPDE1B inhibitor, while (±)-LSF most strongly inhibits hrPDE3A and hrPDE4B. GRMS-55 decreased TNF-alpha levels in vivo and CIA progression with IC 50 of 1.06 and 0.26 mg/L, while (±)-LSF with IC 50 of 5.80 and 1.06 mg/L, respectively. Moreover, GRMS-55 significantly ameliorated symptoms of ConA-induced hepatitis. Conclusions PDE4B but not PDE4D inhibition appears to be mainly engaged in anti-inflammatory activity of the studied compounds. GRMS-55 and (±)-LSF seem to be promising candidates for future studies on the treatment of immunerelated diseases. The developed PK/PD models may be used to assess the anti-inflammatory and anti-arthritic potency of new compounds for the treatment of rheumatoid arthritis and other inflammatory disorders.

In this study, the neuropathological changes induced by chronic unpredictable stress (CUS) and chronic mild stress (CMS) in calbindin D-28K (CB) and parvalbumin (PV) immunoreactive neurons in the rat hippocampus were demonstrated. We used immunohistochemical techniques to quantify the numerical density and morphological changes of PV immunoreactive and CB immunoreactive neurons in the dentate gyrus (DG) and the CA1 and CA3 regions of the hippocampus. We also assessed cell proliferation (Ki-67) and apoptotic processes (active caspase-3) in the DG. We found a significant decrease (16.6% for CUS and 13.3% for CMS) in the numerical density of granule cells (GC), alterations in the CB immunoreactive cells of the GC in the DG and an impairment of mossy fiber CB immunolabelling in the CA3. These changes were not accompanied by a decrease in Ki-67 labeling or the level of caspase-3 in the DG. These data indicate a stress-induced reduction of calcium binding neuron parameters, which may be related to the behavioral paradigms exhibited in these models.

This study was designed to analyze the effect of environmental oxidative stress on human placental monooxygenases, glutathione S-transferase (GST) activity and polycyclic aromatic hydrocarbon (PAH)–DNA adducts in human term placentas from radioactivity-contaminated and chemically-polluted areas of the Ukraine and Belarus, and to compare these biomarkers to the newborn’s general health status. Placental PAH–DNA adduct formation, GST activity, 7-ethoxycoumarin O-deethylase (ECOD) activity, and thiobarbituric reactive substances (TBARS), an index of lipid peroxidation, were measured in groups of women exposed to different levels of radioactivity and PAH pollution. The in vitro metabolism data, obtained from 143 human placental samples at term, were compared to indices of maternal and newborn health. The highest ECOD activity was recorded in placentas obtained from chemically-polluted areas and a radioactivity-contaminated area; the ECOD activity was 7-fold and 2-fold higher compared to the region considered to be “clean”. Newborns with the most compromised health status displayed the greatest down-regulation of GST activity (144–162 mU mg protein−1 vs. 258–395 mU mg protein−1), enhanced ECOD activity and the highest level of PAH–DNA adduct formation. The highest level of TBARS was observed in women exposed to the highest levels of radiation. The efficiency of placental detoxification negatively correlated with maternal age and the health status of the newborn. Environmental oxidative stress was related to an increase in anemia, threatened abortions, toxemia, fetal hypoxia, spontaneous abortions and fetal hypotrophy. Our data suggest that chemically- or radioactivity-induced oxidative stress enhance cytochrome P450-mediated enzymatic activities potentially resulting in increased formation of reactive metabolites. The activity of GSH-transferase is not enhanced. This imbalance in detoxification capacity can be measured as increased production of PAH–DNA adducts, decreased lipid peroxidation and compromised fetal health.

Reductions in the number and size of neurons in the medial prefrontal cortex (mPFC) have been documented in many post-mortem studies of depressed patients and animals exposed to stress. Here, we examined the effect of chronic unpredictable stress (CUS) and chronic mild stress (CMS) on specific populations of neurons in the rat mPFC. Antibodies directed against parvalbumin (PV), calbindin D-28K (CB) and active caspase-3 have been used to quantify the numerical density of PV-immunoreactive (PV-ir), CB-ir and active caspase-3-ir cells, and to measure the relative optical density of neuropil. CUS decreased the density of CB-ir neurons and the optical density of CB-ir neuropil. In turn, CMS increased the densities of both CB-ir neurons and neuropil, while PV-ir neurons and PV-ir neuropil were not changed. The frequency distribution of neuronal surface areas was significantly different only for PV-ir neurons, and only between the control and CUS group. CMS reduced the density of active caspase-3-ir cells while CUS did not. We concluded that the mPFC reveals a different pattern of changes in neurons containing calcium binding proteins and active caspase-3 immunoreactivity in response to CUS and CMS.