6-hydroxydopamine lesions of the striatum lead to the alterations of dopamine receptor mrna in parkinsonian rats

The effects of four-site intrastriatal 6-hydroxydopamine (6-OHDA) lesions were examined in adult male rats. Five days after the lesions the animals were checked for specific rotational behavior induced by middle dose of amphetamine and the results confirmed the effectiveness of the lesions. The RNAs from the striatum were isolated at different time points after the lesion, and the RT-PCR analyse were performed for the D1 and D2 receptor mRNA. The results show a decline in the D2 receptor mRNA level (40%) at 6 h and 24 h points while this change was not observed seven days after the lesion. In contrast, no statistically significant changes in the level of the D1 receptor mRNA after the lesion at any time point were found.Ispitivani su efekti četiri ubodne 6-hidroksidopaminske (6-OHDA) lezije striatuma kod odraslih mužjaka pacova. Pet dana nakon lezije, životinje su testirane na specifično rotaciono ponaš anje pod uticajem srednje doze amfetamina i rezultati su potvrdili efikasnost lezije. RNK iz striatuma su izolovane u različitim vremenskim tačkama nakon lezije i urađena je RT-PCR analiza iRNK za D1 i D2 dopaminske receptore. Rezultati pokazuju smanjivanje nivoa iRNK za D2 receptor (40%) 6 h i 24 h nakon lezije, dok sedam dana nakon lezije nema promena. Za razliku od ovih rezultata, u nivou iRNK za D1 receptor ne postoje statistički značajne razlike u bilo kojoj vremenskoj tački

Changes in expression of GFAP, ApoE and APP mRNA and protein levels in the adult rat brain following cortical injury

The recovery period following cortical injury (CI) is characterized by a dynamic and highly complex interplay between beneficial and detrimental events. The aim of this study was to examine the expressions of Glial Fibrillary Acidic Protein (GFAP), Apolipoprotein E (ApoE) and Amyloid Precursor Protein (APP), all of which are involved in brain plasticity and neurodegeneration. Our results reveal that CI strongly influenced GFAP, ApoE and APP mRNA expression, as well as GFAP and ApoE protein expression. Considering the pivotal role of these proteins in the brain, the obtained results point to their potential contribution in neurodegeneration and consequent Alzheimer's disease development.Projekat ministarstva br. 17305

The high-dose fish oil (FO) supplementation increased Mfsd2a expression in the retina of healthy mice

Mfsd2a is expressed mainly in the endothelial cells and is an essential regulator of blood vessel transcytosis. Therefore, decrease in Mfsd2a expression can be a risk factor for developing leaky blood vessels. Mfsd2a is also the main docosahexaenoic acid (DHA, C22:6n3) transporter. DHA, an omega-3 fatty acid, is one of the main structural lipids of the neuronal and vascular retina, crucial for the normal functioning of photoreceptors (PRs). However, the capacity of the retina to synthesize DHA is limited, and the maintenance of retinal DHA content relies on the uptake from bloodborne lipids. The currently recommended FO doses yielded low PUFAs tissue bioavailability, and supplementation with higher doses has been increasingly recommended. Nevertheless, the effects of higher FO doses on retinal Mfsd2a expression and blood vessels coverage are unknown. Western blot and qPCR analyses showed that high dose FO supplementation increased Mfsd2a expression in the retina. Immunohistochemical analyses of Mfsd2a expression on retinal blood vessels (labeled with 488-conjugated Lycopersicon esculentum, lectin) and subsequent ImageJ analyses revealed 1.32-fold increase in the Mfsd2a retinal blood vessel coverage. In the same time the pericyte blood vessel coverage (CD13+ cells) was not affected with FO supplementation, and the increase in Mfsd2a blood vessel expression is not the result of the increased pericyte coverage. Therefore, the high-dose FO supplementation emerges as the prophylactic fortifier of the retinal blood vessels that can serve either as prophylaxis in the healthy eye or as an adjuvant in developing targeted manipulations of the barrier during diseases.Poster Session: Brain Metabolism & Dietary Intervention

Neonatal Propofol Anesthesia Changes Expression of Synaptic Plasticity Proteins and Increases Stereotypic and Anxyolitic Behavior in Adult Rats

Propofol is a general anesthetic commonly used in pediatric clinical practices. Experimental findings demonstrate that anesthetics induce widespread apoptosis and cognitive decline in a developing brain. Although anesthesia-mediated neurotoxicity is the most prominent during intense period of synaptogenesis, the effects of an early anesthesia exposure on the synapses are not well understood. The aim of this study was to examine the effects of neonatal propofol anesthesia on the expression of key proteins that participate in synaptogenesis and synaptic plasticity and to evaluate long-term neurobehavioral abnormalities in the mature adult brain. Propofol-injected 7-day-old rats were maintained under 2-, 4-, and 6-h-long anesthesia and sacrificed 0, 4, 16, and 24 h after the termination of each exposure. We showed that propofol anesthesia strongly influenced spatiotemporal expression and/or proteolytic processing of crucial presynaptic (GAP-43, synaptophysin, α-synuclein), trans-synaptic (N-cadherin), and postsynaptic (drebrin, MAP-2) proteins in the cortex and thalamus. An overall decrease of synaptophysin, α-synuclein, N-cadherin, and drebrin indicated impaired function and structure of the synaptic contacts immediately after anesthesia cessation. GAP-43 and MAP-2 adult and juvenile isoforms are upregulated following anesthesia, suggesting compensatory mechanism in the maintaining of the structural integrity and stabilization of developing axons and dendritic arbors. Neonatal propofol exposure significantly altered spontaneous motor activity (increased stereotypic/repetitive movements) and changed emotional behavior (reduced anxiety-like response) in the adulthood, 6 months later. These findings suggest that propofol anesthesia is synaptotoxic in the developing brain, disturbing synaptic dynamics and producing neuroplastic changes permanently incorporated into existing networks with long-lasting functional consequences

Changes in expression of GFAP, ApoE and APP mRNA and protein levels in the adult rat brain following cortical injury

The recovery period following cortical injury (CI) is characterized by a dynamic and highly complex interplay between beneficial and detrimental events. The aim of this study was to examine the expressions of Glial Fibrillary Acidic Protein (GFAP), Apolipoprotein E (ApoE) and Amyloid Precursor Protein (APP), all of which are involved in brain plasticity and neurodegeneration. Our results reveal that CI strongly influenced GFAP, ApoE and APP mRNA expression, as well as GFAP and ApoE protein expression. Considering the pivotal role of these proteins in the brain, the obtained results point to their potential contribution in neurodegeneration and consequent Alzheimer's disease development.Projekat ministarstva br. 17305

Antiproliferative Effect of 13-cis-Retinoic Acid is Associated with Granulocyte Differentiation and Decrease in Cyclin B1 and Bcl-2 Protein Levels in G0/G1 Arrested HL-60 Cells

Retinoic acid (RA), similar to specific growth factors, can induce differentiation of proliferating promyelocytic precursors into terminally differentiated granulocytes, although little is known about effects of its 13-cis isomer on promyelocytic leukemia (PML). In this study we demonstrate that 13-cis-RA has a dose and time-dependant antiproliferative effect on HL-60 PML cell line, that it induces cell accumulation in resting G0/G1 phase of the cell cycle followed by an increase in CD11b granulocyte differentiation antigen expression. The obtained increase in the percentage of HL-60 cells in G0/G1 phase and complementary decrease in S phase of the cell cycle are accompanied by a decrease in the expression of cell cycle regulatory molecule cyclin B1. We also show the induction of interferon regulatory factor-I (IRF- I) transcription that can, also, to some extent contribute to the antiproliferative effect of l 3-cis-RA. Furthermore, down-regulation of BcI-2 protein expression in I 3-cis-RA treated HL-60 cells may contribute to sensitivity to apoptosis of growth arrested HL-60 promyelocytic cells.Ministry of Science and technology of the Republic of Serbia [145056

The influence of propofol anesthesia exposure on nonaversive memory retrieval and expression of molecules involved in memory process in the dorsal hippocampus in peripubertal rats.

BACKGROUND The effects of anesthetic drugs on postoperative cognitive function in children are not well defined and have not been experimentally addressed. AIMS The present study aimed to examine the influence of propofol anesthesia exposure on nonaversive hippocampus-dependent learning and biochemical changes involved in memory process in the dorsal hippocampus, in peripubertal rats as the rodent model of periadolescence. METHODS The intersession spatial habituation and the novel object recognition tasks were used to assess spatial and nonspatial, nonaversive hippocampus-dependent learning. The exposure to anesthesia was performed after comparably long acquisition phases in both tasks. Behavioral testing lasted for 2 consecutive days (24-hour retention period). Changes in the expression of molecules involved in memory retrieval/reconsolidation were examined in the dorsal hippocampus by Western blot and immunohistochemistry, at the time of behavioral testing. RESULTS Exposure to propofol anesthesia resulted in inappropriate assessment of spatial novelty at the beginning of the test session and affected continuation of acquisition in the spatial habituation test. The treatment did not affect recognition of the novel object at the beginning of the test session but it attenuated overall preference to novelty, reflecting retrieval of a weak memory. The expression of phosphorylated extracellular signal-regulated kinase 2 (involved in memory retrieval) was decreased while the level of phosphorylated Ca2+ /calmodulin-dependent protein kinase IIα and early growth response protein 1 (involved in memory reconsolidation) was increased in the dorsal hippocampus. The level of Finkel-Biskis-Jinkins murine osteosarcoma viral oncogene homolog B (neuronal activity indicator) was increased in the dorsal dentate gyrus. Enhanced exploratory activity was still evident in the propofol anesthesia exposure (PAE) group 48 hour after the treatment in both tasks. CONCLUSION In peripubertal rats, propofol anesthesia exposure affects memory retrieval and acquisition of new learning in the spatial and nonspatial, nonaversive learning tasks 24 hour after the treatment, along with the expression of molecules that participate in memory retrieval/reconsolidation in the dorsal hippocampus. These results may have clinical implications, favoring control of basic cognitive functions in older children after the propofol exposure

Antiproliferative Effect of 13-cis-Retinoic Acid is Associated with Granulocyte Differentiation and Decrease in Cyclin B1 and Bcl-2 Protein Levels in G0/G1 Arrested HL-60 Cells

Retinoic acid (RA), similar to specific growth factors, can induce differentiation of proliferating promyelocytic precursors into terminally differentiated granulocytes, although little is known about effects of its 13-cis isomer on promyelocytic leukemia (PML). In this study we demonstrate that 13-cis-RA has a dose and time-dependant antiproliferative effect on HL-60 PML cell line, that it induces cell accumulation in resting G0/G1 phase of the cell cycle followed by an increase in CD11b granulocyte differentiation antigen expression. The obtained increase in the percentage of HL-60 cells in G0/G1 phase and complementary decrease in S phase of the cell cycle are accompanied by a decrease in the expression of cell cycle regulatory molecule cyclin B1. We also show the induction of interferon regulatory factor-I (IRF- I) transcription that can, also, to some extent contribute to the antiproliferative effect of l 3-cis-RA. Furthermore, down-regulation of BcI-2 protein expression in I 3-cis-RA treated HL-60 cells may contribute to sensitivity to apoptosis of growth arrested HL-60 promyelocytic cells.Ministry of Science and technology of the Republic of Serbia [145056

Brain molecular changes and behavioral alterations induced by propofol anesthesia exposure in peripubertal rats

Background: Propofol is commonly used in modern anesthesiology. Some findings suggest that it is highly addictive. Aim: In this study it was examined whether propofol anesthesia exposure was able to induce behavioral alterations and brain molecular changes already described in addictive drug usage in peripubertal rats, during the onset of mid/periadolescence as a developmental period with increasing vulnerability to drug addiction. Methods: The expression of D1 dopamine receptor, a dopamine, and cAMP-regulated phosphoprotein with a Mr 32 000; Ca 2+ /calmodulin-dependent protein kinase IIα; and Finkel-Biskis-Jinkins murine osteosarcoma viral oncogene homolog-B was examined in peripubertal rats 4, 24, and 48 hour after propofol anesthesia exposure by Western blot and immunohistochemistry. Brain regions of interest were the medial prefrontal cortex, the striatum, and the thalamus. Anxiety and behavioral cross-sensitization to d-amphetamine were examined as well. Results: Significant increase in the expression of dopamine and cAMP-regulated phosphoprotein with a Mr 32 000 phosphorylated at threonine 34, a postsynaptic marker of dopaminergic neurotransmission, and Finkel-Biskis-Jinkins murine osteosarcoma viral oncogene homolog-B, a marker of neuronal activity, was detected in the thalamus of experimental animals 4-24 hour after the treatment, with the accent on the paraventricular thalamic nucleus. Significant increase in the expression of Ca 2+ /calmodulin-dependent protein kinase IIα phosphorylated at threonine 286, a sensor of synaptic activity, was observed in the prefrontal cortex and the striatum 24 hour after propofol anesthesia exposure. It was accompanied by a significant decrease in Finkel-Biskis-Jinkins murine osteosarcoma viral oncogene homolog-B expression in the striatum. Decreased behavioral inhibition in aversive environment and increased motor response to d-amphetamine in a context-independent manner were observed as well. Conclusion: In peripubertal rats, propofol anesthesia exposure induces transient molecular and behavioral response that share similarities with those reported previously for addictive drugs. In the absence of additional pharmacological manipulation, all detected effects receded within 48 hour after the treatment.Pediatric Anesthesia (2017), 27(9): 962-97

Short-term fish oil supplementation applied in presymptomatic stage of Alzheimer's disease enhances microglial/macrophage barrier and prevents neuritic dystrophy in parietal cortex of 5xFAD mouse model.

Dystrophic neurites and activated microglia are one of the main neuropathological characteristics of Alzheimer's disease (AD). Although the use of supplements with omega-3 fatty acids has been associated with reduced risk and lessened AD pathology, it still remains elusive whether such a treatment could affect dystrophic neurites (DNs) formation and microglia/macrophage behavior in the early phase of disease. We analyzed the effects of short-term (3 weeks) fish oil supplementation on DNs formation, tau hyperphosphorylation, Amyloid-beta peptide 1-42 (Aβ42) levels and microglial/macrophage response to AD pathology in the parietal cortex of 4-month-old 5xFAD mice, a mouse model of AD. The present study shows for the first time that short-term FO supplementation applied in presymptomatic stage of AD, alters the behaviour of microglia/macrophages prompting them to establish a physical barrier around amyloid plaques. This barrier significantly suppresses DNs formation through the reduction of both Aβ content and tau hyperphosphorylation. Moreover, the short-term FO treatment neither suppresses inflammation nor enhances phagocytic properties of microglia/macrophages in the response to Aβ pathology, the effects most commonly attributed to the fish oil supplementation. Our findings suggest that fish oil consumption may play an important role in modulating microglial/macrophage response and ameliorating the AD pathology in presymptomatic stage of Alzheimer's disease