Effects of prenatal exposure to inflammation coupled with prepubertal stress on prefrontal white matter structure and related molecules in adult mouse offspring.

Maternal immune activation (MIA) by inflammatory agents such as lipopolysaccharide (LPS) and prepubertal stress (PS) may individually and collectively affect the central nervous system (CNS) during adulthood. Here, we intended to assess the effects of MIA, alone or combined with PS, on prefrontal white matter structure and its related molecules in adult mice offspring. Pregnant mice received either an i.p. dose of LPS (50 µg/kg) on gestational day 17 (GD17) or normal saline. Their pups were exposed to stress from postnatal days (PD) 30 to PD38 or no stress during prepubertal development. We randomly chose 56-day-old male offspring (n = 2 offspring per mother) from each group and isolated their prefrontal areas according to relevant protocols. The tissue samples were prepared for structural, histological, and molecular examinations. The LPS + stress group had evidence of increased damage in the white matter structures compared to the control, stress, and LPS groups (p < 0.05). The LPS + stress group also had significant downregulation of the genes involved in white matter formation (Sox10, Olig1, myelin regulatory factor, and Wnt compared with the control, stress, and LPS groups (p < 0.05). In conclusion, although each manipulation individually resulted in small changes in myelination, their combined effects were more pronounced. These changes were parallel to abnormal expression levels of the molecular factors that contribute to myelination.

Alpha lipoic acid ameliorates detrimental effects of maternal lipopolysaccharides exposure on prefrontal white matter in adult male offspring rats.

BACKGROUND: Activation of the maternal immune system by lipopolysaccharide (LPS) increases the production of proinflammatory cytokines, free radicals, and reactive oxygen species (ROS), all of which play a significant role in the pathogenesis of many offspring neurodevelopmental disorders. Alpha Lipoic Acid (ALA) is a natural compound that has anti-inflammatory and antioxidant properties. This study was performed to assess the effect of prenatal exposure to LPS on the prefrontal white matter of rat offspring and evaluate the potential protective effects of ALA co-administration during pregnancy. METHODS: Pregnant Wistar rats were randomly divided into six groups (n = 6 each group): (1) control, (2) received LPS (100 µg/kg, intraperitoneally (IP) on gestational day 9.5 (GD 9.5), (3) received ALA (20 mg/kg) from GD1 to GD11, (4) LPS+ALA received LPS on GD9.5 and ALA from GD1 to GD11, (5 and 6) received LPS and ALA vehicle respectively. In each group, 21-day old male offspring (2 male pups from each mother) was harvested, and then their prefrontal white matter was separated and prepared for the ultrastructural, stereological, and molecular assays. RESULTS: In utero exposure to LPS led to a significant decrease in nerve cell counts, ultrastructural alterations in myelinated axons, and abnormal changes in genes expression of Sox10,Olig1,yrf,Wnt in the prefrontal of the rat offspring. Co-administration of ALA resulted in amelioration of those abnormal changes in the LPS rat offspring. CONCLUSION: The findings of our preclinical study, explore that prenatal ALA treatment efficiently protects the nervous system against LPS induced abnormal changes in the offspring.

Risperidone accelerates bone loss in rats with autistic-like deficits induced by maternal lipopolysaccharides exposure.

AIMS: Patients with neurodevelopmental disorders, usually suffer from bone diseases. Many studies have revealed a higher risk of fracture after atypical antipsychotic drug Risperidone (RIS) treatment, which is usually used to treat such disorders. It remains debatable whether neurodevelopmental disorders by itself are the cause of bone diseases or pharmacotherapy may be the reason. MATERIALS AND METHODS: This study attempts to evaluate the biomechanical, histological, stereological, and molecular properties of bones in the offspring of Lipopolysaccharide (LPS) and saline-treated mothers that received saline, drug vehicle or the atypical antipsychotic drug risperidone (RIS) at different days of postnatal development. After postnatal drug treatment, animals were assessed for autistic-like behaviors. Then their bones were taken for evaluations. RESULTS: Maternal LPS exposure resulted in deficits in all behavioral tests and RIS ameliorated these behaviors (p < 0.01& p < 0.05). The administration of LPS and RIS individually led to a significant decrease in the biomechanical parameters such as bone stiffness, strength and the energy used to fracture of bone. The numerical density of osteocalcin-positive cells were significantly decreased in these groups. These rats also had decreased RUNX2 and osteocalcin gene expression. When LPS rats were treated with RIS, these conditions were accelerated (p < 0.001). DISCUSSIONS: The results of our preclinical study, consistent with previous studies in animals, explore that autistic-like deficits induced by prenatal exposure to LPS, can reduce bone stability and bone mass similar to those observed in neurodevelopmental disorders, and, for the first time, reveal that this condition worsened when these animals were treated with RIS.

Peripubertal stress following maternal immune activation sex-dependently alters depression-like behaviors in offspring.

There is an increasing evidence that maternal immune activation can render the offspring more vulnerable to the impacts of peripubertal stress on behavioral abnormalities in adulthood. The aim of this study was to investigate the combined effects of maternal immune activation and peripubertal stress on depression-related behaviors in male and female offspring. Pregnant mice were treated with lipopolysaccharides (LPS) or vehicle, and then offspring were subjected to stressful conditions or left unstressed during peripubertal period. Four behavioral tests including novelty-suppressed feeding test, sucrose preference test, tail suspension test, and forced swim test were used to measure depression-related behaviors in offspring. The activity of hypothalamic-pituitary-adrenal (HPA) or - gonadal (HPG) axes were also evaluated by measuring basal and stress-induced corticosterone, testosterone and estradiol levels in the serum of offspring. Our findings revealed that mild maternal immune activation and peripubertal stress interacted synergistically to induce depression-related symptoms and HPA axis hyperactivity in male offspring, whereas no significant changes were observed in female offspring. We also found that this combination of environmental factors significantly decreased serum testosterone and estradiol levels in adult male and female offspring respectively. There were also significant correlations between behavioral parameters and hormones. Taken together, these findings show that the combination of two environmental risk factors can predispose the male offspring to increased depression-related symptoms in adulthood as compared to the females. This study suggests that the combination of maternal immune activation and peripubertal stress can alter depression-related behaviors and HPA axis function in a sex-dependent manner.

Alpha lipoic acid ameliorates THIM-induced prefrontal cell loss and abnormal enzymatically contents in the developing rat.

Thimerosal (THIM) is a common preservative used in many pharmaceutical drugs, vaccines, cosmetics and many other products. Today, it was somewhat clear that Thimerosal (THIM) is a neurotoxicant preservative. We aimed to use of a suitable agent for preventing of THIM side effects on brain. Therefore, in this research, the protective effects of Alpha Lipoic Acid (ALA), against THIM-induced brain cell loss, changes in neuroimmune cell and enzymatically contents were examined. Male Wistar rats (n = 60) were randomly distributed into five groups: 1- THIM group; this group received THIM at dose of 300 µg /kg on 7, 9, 11, 15 days after birth 2- ALA group; received ALA (20 mg/kg) in the same order. 3- THIM & ALA group; this group received ALA in the same dose, 30 min before THIM administration.4& 5; Saline and ALA vehicle groups were also included. At 56th postnatal day, samples of the prefrontal cortex were collected and prepared for stereological, immune-histochemical, and enzymatic evaluations. The result showed that ALA, prevents the adverse effects of THIM on brain cell loss, abnormal changes in neuroimmune cells (p < 0.05), prefrontal cortex volume (p < 0.05), and the glutathione content of prefrontal cortex (p < 0.05). In conclusion, neonatal exposure to THIM can induce abnormal alterations in neuroimmune cells and brain cell density as well as prefrontal cortex volume & glutathione content, and ALA can ameliorate these abnormalities.

Alterations of neuroimmune cell density and pro-inflammatory cytokines in response to thimerosal in prefrontal lobe of male rats.

Evidence suggests that the effect of heavy metals on neuroimmune cells lead to neurogenic inflammatory responses. In this study, immune cells [mast cells (MCs) and microglia] and pro-neuroinflammation cytokines (interleukin-1b and tumor necrosis factor-α) were assessed in the prefrontal lobe of rat brains exposed to thimerosal in different timeframes. A total of 108 neonatal Wistar rats were divided into three groups having three subgroups. The experimental groups received a single dose of thimerosal (300 µg/kg) postnatally at 7, 9, 11, and 15 days. The vehicle groups received similar injections of phosphate-buffered saline in a similar manner. The control groups received nothing. Samples of the prefrontal cortex were collected and prepared for stereological, immunohistochemical, and molecular studies at timeframes of 12 or 48 h (acute phase) and 8 days (subchronic phase) after the last injection. The average density of the microglia and MCs increased significantly in the experimental groups. This increase was more evident in the 48 h group. At 8 days after the last injection, there was a significant decrease in the density of the MCs compared to the 12 and 48 h groups. Alterations in pro-inflammatory cytokines were significant for all timeframes. This increase was more evident in the 48 h group after the last injection. There was a significant decrease in both neuroinflammatory cytokines at 8 days after the last injection. It was found that ethylmercury caused abnormal neurogenic inflammatory reactions and alterations in the neuroimmune cells that remained for a longer period in the brain than in the blood.

Protective role of alpha-lipoic acid in impairments of social and stereotyped behaviors induced by early postnatal administration of thimerosal in male rat.

Aim Thimerosal, a mercury-containing preservative has been widely used in a number of biological and drug products, including many vaccines, and has been studied as a possible etiological factor for some neurodevelopmental disabilities. Here, the protective effects of Alpha Lipoic Acid (ALA), an organosulfur compound derived from Octanoic Acid, on Thimerosal-induced behavioral abnormalities in rat were examined. METHODS: 108 male Wistar rats were divided into three cohorts and treated as follows: 1) Thimerosal at different doses (30, 300, or 3000 µg Hg/kg) in four i.m. injections on 7, 9, 11, 15postnatal days. 2) ALA (at doses of 5, 10 and 20 mg/kg), following the same order; 3) single dose of Thimerosal (3000 µg Hg/kg) plus ALA at different doses (5, 10 or 20 mg/kg), by the previously described method. A saline treated control group and a ALA vehicle control (0.1% NaOH) were also included. At 5 and 8 weeks after birth, rats were evaluated with behavioral tests, to assess locomotor activity, social interactions and stereotyped behaviors, respectively. RESULTS: The data showed that Thimerosal at all doses (30, 300 and 3000 µg Hg/kg) significantly impacted locomotor activity. Thimerosal at doses of 300 and 3000 but not 30 µg Hg/kg impaired social and stereotyped behaviors. In contrast, ALA (at doses of 5, 10 and 20 mg/kg) did not alter behaviors by itself, at doses of 20 mg/kg, it reduced social interaction deficits induced by the highest dose of Thimerosal (3000 µg Hg/kg). Moreover, ALA, at all doses prevented the adverse effects of Thimerosal on stereotyped behaviors. CONCLUSIONS: the results of this preclinical study, consistent with previous studies on mice and rats, reveals that neonatal dose-dependent exposure to Thimerosal mimicking the childhood vaccine schedule can induce abnormal social interactions and stereotyped behaviors similar to those observed in neurodevelopmental disorders such as autism, and, for the first time, revealed that these abnormalities may be ameliorated by ALA. This indicates that ALA may protect against mercurial-induced abnormal behaviors.