Comparing the effects of small molecules BIX-01294, Bay K8644, RG-108 and valproic acid, and their different combinations on induction of pluripotency marker-genes by Oct4 in the mouse brain

Every cell type is characterized by a specific transcriptional profile together with a unique epigenetic landscape. Reprogramming factors such as Oct4, Klf4, Sox2 and c-Myc enable somatic cells to change their transcriptional profile and convert them to pluripotent cells. Small molecules such as BIX-01294, Bay K8644, RG-108 and valproic acid [VPA] are reported as effective molecules for enhancing induction of pluripotency in vitro, however, their effects during in vivo reprogramming are addressed in this experimental study. In this experimental study, Oct4 expressing lentiviral particles and small molecules BIX-01294, Bay K8644 and RG-108 were injected into the right ventricle of mice brain and VPA was systematically administered as oral gavages. Animals treated with different combinations of small molecules for 7 or 14 days in concomitant with Oct4 exogenous expression were compared for expression of pluripotency markers. Total RNA was isolated from the rims of the injected ventricle and quantitative polymerase chain reaction [PCR] was performed to evaluate the expression of endogenous Oct4, Nanog, c-Myc, klf4 and Sox2 as pluripotency markers, and Pax6 and Sox1 as neural stem cell [NSC] markers. Results showed that Oct4 exogenous expression for 7 days induced pluripotency slightly as it was detected by significant enhancement in expression of Nanog [p<0.05]. Combinatorial administration of Oct4 expressing vector and BIX-01294, Bay K8644 and RG-108 did not affect the expression of pluripotency and NSC markers, but VPA treatment along with Oct4 exogenous expression induced Nanog, Klf4 and c-Myc [p<0.001]. VPA treatment before the induction of exogenous Oct4 was more effective and significantly increased the expression of endogenous Oct4, Nanog, Klf4, c-Myc [p<0.01], Pax6 and Sox1 [p<0.001]. These results suggest VPA as the best enhancer of pluripotency among the chemicals tested, especially when applied prior to pluripotency induction by Oct4

Chronic cold-water-induced hypothermia impairs memory retrieval and nepeta menthoides as a traditional "hot" herb reverses the impairment

Iranian Traditional Medicine [ITM] describes a kind of dementia with similar signs and symptoms of Alzheimer's disease [AD]. It explains the pathology of dementia with cold intemperament of the brain, which means that the brain is colder than its healthy form. ITM strategy for treatment of dementia is to heat the brain up by medical "hot" herbs. Nepeta menthoides [NM] is one of these "hot" herbs. To evaluate the veracity of ITM concept about dementia and its treatment, we first try to examine if coldness of brain can make memory impairment. If so, can NM reverse memory impairment? Rats in cold-water-induced hypothermic [CWH] groups were immersed up to the neck in 3.5 [degree sign]C water, for 5 min during 14 consecutive days. As a control, rats were forced to swim in warm water at the same conditions. To eliminate the impact of forced swimming stress, a group of intact rats was also added. After last swimming in day 14, some groups received drug [100 or 500 mg/Kg aqueous extract of NM] or vehicle via i.p. injection. Learning and memory were assessed by Morris water maze, and tau hyperphosphorylation was measured by western blotting. The results showed that CWH impairs learning and memory and induces tau hyperphosphorylation. 100 mg/Kg of NM reversed memory impairment as well as tau hyperphosphorylation. ITM theory about the relationship between brain hypothermia and dementia is in accordance with our findings

Can social instability, food deprivation and food inequality accelerate neuronal aging?

Based on both animal and human studies, inequality in food intake and social instability has adverse effects on the health of individuals and the community. However, it is not known whether social instability, food deprivation and food inequality affect neuronal death and premature aging in young animals. To address this question, the effects of these adverse situations, histopathological changes in hippocampal pyramidal cells and aging process were investigated. Forty eight New Zeeland white male rabbits were divided into six groups and all of them were housed in similar conditions, with 2 animals per cage in a temperaturecontrolled colony room under light-dark cycle. All experimental animals were fed on standard rabbit commercial pellets and different social situations such as food deprivation, inequality in food intake, and unstable social status were applied to experimental groups during eight weeks. Afterward, lipofuscin accumulation and apoptosis, as main markers of aging, were compared to the control group by Long Ziehl Nelseen staining and the terminal deoxynucleotidyl transferase dUTP nick end labeling [TUNEL reaction] assay to reveal the rate of lipofuscin pigment accumulation and TUNEL-reactive apoptotic bodies in the hippocampal pyramidal cells. Serum cortisol level was also measured. Inequality in social situation raised chronic stress [i.e. food deprivation, social inequality and instability] and caused significant changes in lipofuscin accumulation in hippocampal pyramidal cells in comparison to the control group [p<0.005]. The results also showed a significant increase in the ratio of apoptotic to normal cells in all of the stressed groups compared to the control group [p<0.05]. Moreover, application of the social inequality and stresses alone or together modulated levels of cortisol in the experimental group. These findings suggest that food deprivation, inequality and social instability enhance the susceptibility of hippocampal pyramidal cells to apoptosis and premature aging induced by lipofuscin accumulation

effect of swim stress on morphine tolerance development and the possible role of nitric oxide in this process

It has been shown that stress and chronic pain could prevent the development of tolerance to morphine analgesia, which appears to be related to the activation of hypothalamus-pitutitary-adrenal [HPA] axis, activation of neuroendocrine systems and changes in neurochemical levels. Moreover, the involvement of nitric oxide [NO] in the development of tolerance to morphine analgesia has been implicated. In the present study, we have tried to investigate the effect of swim stress, as a painless kind of stress, on the development of tolerance to find out whether the inhibition of tolerance is mediated by the direct effect of pain on the pain conduction pathway, or by its stress aspect. Besides, we evaluated the probable interactions between swim stress, nitric oxide level and the development of morphine tolerance. Adult male Wistar rats, weighing 180-220 g, were used in all these experiments. The experimental groups received chronic morphine [20 mg/kg, i.p], swim stress in 20°C water bath [4 min], or a combination of swim stress and chronic morphine [20 mg/kg, i.p], each for 4 days, while the first control group received saline [1 ml/kg, i.p] for 4 days. On the 5th day, all the experimental and control groups received a single dose of morphine [10 mg/kg i.p]. The second control group received saline for 5 days. The intact group received only one single dose of morphine [10 mg/kg, i.p]. All the mentioned groups were subjected to tail-flick and formalin tests on the 5th day. Other experimental groups were subjected to the assay for measuring nitrite as an indicator of NO, using the Griess method. Our results showed that co-administration of swim stress with chronic morphine prevented the development of morphine tolerance and the level of NO increased in the presence of swim stress [p<0001]. The combination of morphine and swim stress significantly decreased NO production in comparison with the chronic morphine administered group [p<0.001]. These data suggest that the activation of HPA axis and consequently the suppression of [NO] production induced by chronic morphine, lead to the inhibition of morphine tolerance