MicroRNAs (miRNAs) are endogenously expressed small, non-coding transcripts that regulate protein expression. Substantial evidences suggest that miRNAs are enriched in central nervous system, where they are hypothesized to play pivotal roles during neural development. In the present study, we analyzed miRNAs expression in mice cerebral cortex and hippocampus at different developmental stages and found miR-29a increased dramatically at postnatal stages. In addition, we provided strong evidences that miR-29a is enriched in mature neurons both in vitro and in vivo. Further investigation demonstrated that the activation of glutamate receptors induced endogenous miR-29a level in primary neurons. Moreover, we showed that miR-29a directly regulated its target protein Doublecortin (DCX) expression, which further modulated axon branching in primary culture. Together, our results suggested that miR-29a play an important role in neuronal development of mice cerebrum.
Animals ; Axons ; metabolism ; physiology ; Hippocampus ; growth & development ; metabolism ; Mice ; MicroRNAs ; genetics ; metabolism ; Microtubule-Associated Proteins ; genetics ; Neurogenesis ; Neurons ; metabolism ; Neuropeptides ; genetics ; Primary Cell Culture

The current epidemic of obesity and its associated metabolic syndromes impose unprecedented challenges to our society. Despite intensive research on obesity pathogenesis, an effective therapeutic strategy to treat and cure obesity is still lacking. Exciting studies in last decades have established the importance of the leptin neural pathway in the hypothalamus in the regulation of body weight homeostasis. Important hypothalamic neuropeptides have been identified as critical neurotransmitters from leptin-sensitive neurons to mediate leptin action. Recent research advance has significantly expanded the list of neurotransmitters involved in body weight-regulating neural pathways, including fast-acting neurotransmitters, gamma-aminobutyric acid (GABA) and glutamate. Given the limited knowledge on the leptin neural pathway for body weight homeostasis, understanding the function of neurotransmitters released from key neurons for energy balance regulation is essential for delineating leptin neural pathway and eventually for designing effective therapeutic drugs against the obesity epidemic.
Animals ; Energy Metabolism ; Gene Expression ; Humans ; Hunger ; Hypothalamus ; metabolism ; physiology ; Leptin ; metabolism ; physiology ; Neural Pathways ; metabolism ; Neuropeptides ; genetics ; metabolism ; Obesity ; metabolism

AIMTo study the effect and significances of two-week hypoxia on the expression of intermedin/adrenomedullin2 (IMD/ADM2) in plasma and the tissues of heart and lung in rats.

METHODSTwenty male SD rats were randomly divided into normal control group and hypoxia group. The concentrations of IMD/ADM2 and adrenomedullin (ADM) in plasma, right ventricle and lung tissue were measured by radioimmunoassay. RT-PCR was used to detect the mRNA levels of IMD/ADM2 and ADM in right ventricle and lung tissue.

RESULTS(1) The mean pulmonary arterial pressure (mPAP) and the weight ratio of right ventricle (RV) to left ventricle plus septum (LV + S) of hypoxia group were significantly higher than those of normal control group (P < 0.01). (2) The concentrations of IMD/ADM2 and ADM in plasma were significantly higher in hypoxia group, compared with normal control group (P < 0.01). (3) The concentration of ADM in right ventricle and lung tissue in hypoxia group was significantly higher than that in normal control group (P < 0.01), while there was no significant difference in IMD/ADM2 between the two groups. (4) The mRNA levels of IMD/ADM2 and ADM in right ventricle and lung tissues were significantly up-regulated in hypoxia group (P < 0.05).

CONCLUSIONThe expressions of IMD/ADM2 peptides and gene in plasma, right ventricular and pulmonary tissues are different in the early-middle pathological proceeding of pulmonary hypertension induced by two-week hypoxia in rats.

Adrenomedullin ; blood ; genetics ; metabolism ; Animals ; Hypertension, Pulmonary ; etiology ; metabolism ; Hypoxia ; complications ; metabolism ; Lung ; metabolism ; Male ; Myocardium ; metabolism ; Neuropeptides ; blood ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley

OBJECTIVE: To explore the change of orexin-A expression in hepatic reperfusion and their association with liver injury, and to find out the role of orexin-A in traumatic stress responses. METHODS: A 70% hepatic reperfusion model of rats was established, setting groups of sham-operation and injury ones with different reperfusion time. A self-produced radioimmunoassay and relevant kits were used to detect the protein level of orexin-A in the plasma and the hypothalamus, serum glucose, total anti-oxidation capacity and alanine transaminase, HE staining and immunohistochemistry were used to investigate the pathological variation and protein expression of orexin-A in the liver, while RT-PCR was applied to observe mRNA expression of orexin-A in the hypothalamus and the liver. RESULTS: Both the shape of standard curve and metrical results of the self-produced orexin-A radioimmunoassay were good. Protein levels of orexin-A in the plasma and the hypothalamus in each reperfusion group showed no significant change. Serum glucose and total anti-oxidation capacity increased significantly at the later phase of injury. There was significant and positive linear correlation between the plasma orexin-A and serum glucose and total anti-oxidation capacity; serum alanine transaminase in each reperfusion group was significantly higher, and liver damage was significantly alleviated at the later phase of the injury. Different extents of variation were observed in protein expression of orexin-A in the liver and its mRNA expression in the hypothalamus and the liver. CONCLUSION Orexin-A undergoes significant changes during hepatic reperfusion, indicating that orexin-A participates in the modulation of hepatic reperfusion-induced liver injury and internal disorders.
Animals ; Hypothalamus ; metabolism ; Intracellular Signaling Peptides and Proteins ; genetics ; metabolism ; Liver ; blood supply ; metabolism ; Male ; Neuropeptides ; genetics ; metabolism ; Orexins ; RNA, Messenger ; genetics ; metabolism ; Radioimmunoassay ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; metabolism

BACKGROUNDSleep/wake disturbances in patients with amyotrophic lateral sclerosis (ALS) are well-documented, however, no animal or mechanistic studies on these disturbances exist. Orexin is a crucial neurotransmitter in promoting wakefulness in sleep/wake regulation, and may play an important role in sleep disturbances in ALS. In this study, we used SOD1-G93A transgenic mice as an ALS mouse model to investigate the sleep/wake disturbances and their possible mechanisms in ALS.

METHODSElectroencephalogram/electromyogram recordings were performed in SOD1-G93A transgenic mice and their littermate control mice at the ages of 90 and 120 days, and the samples obtained from these groups were subjected to quantitative reverse transcriptase-polymerase chain reaction, western blotting, and enzyme-linked immunosorbent assay.

RESULTSFor the first time in SOD1-G93A transgenic mice, we observed significantly increased wakefulness, reduced sleep time, and up-regulated orexins (prepro-orexin, orexin A and B) at both 90 and 120 days. Correlation analysis confirmed moderate to high correlations between sleep/wake time (total sleep time, wakefulness time, rapid eye movement [REM] sleep time, non-REM sleep time, and deep sleep time) and increase in orexins (prepro-orexin, orexin A and B).

CONCLUSIONSleep/wake disturbances occur before disease onset in this ALS mouse model. Increased orexins may promote wakefulness and result in these disturbances before and after disease onset, thus making them potential therapeutic targets for amelioration of sleep disturbances in ALS. Further studies are required to elucidate the underlying mechanisms in the future.

Amyotrophic Lateral Sclerosis ; genetics ; metabolism ; Animals ; Female ; Intracellular Signaling Peptides and Proteins ; genetics ; metabolism ; Male ; Mice ; Mice, Transgenic ; Neuropeptides ; genetics ; metabolism ; Orexins ; Reverse Transcriptase Polymerase Chain Reaction ; Sleep ; physiology ; Superoxide Dismutase ; genetics ; metabolism ; Superoxide Dismutase-1 ; Wakefulness ; physiology

OBJECTIVETo examine the changes of expressions of orexin A, orexin receptor-1 (OX1R), prepro-orexin (Prepro-OX) mRNA, OX1R mRNA and ob-R of hypothalamus in rats with chronic renal failure (CRF).

METHODSSixty-two male Wister rats weighing 200-250 g were divided into three groups, including group 1 (normal, n = 5), group 2 (sham-operated, n = 25) and group 3 (CRF, n = 32). Hypothalamus orexin A was assayed by radioimmunoassay. Serum leptin was assayed by enzyme linked immunosorbent assay. The expression of Prepro-OX mRNA and OX1R mRNA of hypothalamus were measured by reverse transcription polymerase chain reaction, and expression of orexin A, OX1R and ob-R by immunohistochemistry. Automatic biochemical analyzer was used to measure the serum creatinine.

RESULTSHypothalamus orexin A levels were negatively correlated (r = -0.63, P < 0.001) with serum leptin levels in the rats. The expression of hypothalamus Prepro-OX mRNA in CRF rats was significantly lower than that of sham-operation at week 12 (P < 0.01). Hypothalamus Prepro-OX mRNA levels were negatively correlated (r = -0.81, P < 0.001) with the levels of serum leptin and serum creatinine (r = -0.68, P < 0.05) in the rats at week 12. The expression of hypothalamus OX1R mRNA in CRF rats was lower than that of sham-operation at week 12 (P > 0.05). Specific immunoreactivity for orexin A was present in perikeryon of the hypothalamus neuron. Specific OX1R-like immunoreactivity was observed in some nerve fibres. Specific immunoreactivity for ob-R was present in membranes of the hypothalamus neuron. Hypothalamus neurons of orexin A-like specific immunoreactivity in CRF rats were significantly fewer than those in shamoperated rats at week 8. Hypothalamus neurons of OX1R-like specific immunoreactivity in CRF rats were similar to those in sham-operated rat at week 8. Hypothalamus neurons of ob-R-like specific immunoreactivity in CRF rats were significantly more than those in sham-operated rats at week 8.

CONCLUSIONSThe lower hypothalamus orexin A levels may be induced by high serum leptin level in CRF rats. The lower expression of hypothalamus Prepro-OX mRNA in CRF rats may be one of the main causes inducing lower hypothalamus orexin A. The expression of OX1R in hypothalamus neurons is somewhat reduced and the expression of ob-R in hypothalamus neurons is somewhat raised in CRF rats. These remain to be studied further.

Animals ; Carrier Proteins ; genetics ; metabolism ; Hypothalamus ; metabolism ; Intracellular Signaling Peptides and Proteins ; Kidney Failure, Chronic ; metabolism ; Leptin ; genetics ; metabolism ; Male ; Neuropeptides ; genetics ; metabolism ; Neurotransmitter Agents ; genetics ; metabolism ; Orexin Receptors ; Orexins ; Protein Precursors ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Random Allocation ; Rats ; Rats, Wistar ; Receptors, Cell Surface ; genetics ; metabolism ; Receptors, G-Protein-Coupled ; Receptors, Leptin ; Receptors, Neuropeptide ; genetics ; metabolism

Brain ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; Gene Expression ; Neuropeptides ; biosynthesis ; genetics ; Proto-Oncogene Proteins c-fos ; biosynthesis ; genetics ; Proto-Oncogene Proteins c-jun ; biosynthesis ; genetics ; RNA, Messenger ; biosynthesis ; genetics

OBJECTIVETo observe the expression and function of extraction.

METHODSReal-time reverse transcription PCR paralleled with vitro-established cRNA standard curves was applied to measure the expression of Nav1.8, Nav1.9 at 30 min, 2 h, 1 d, 3 d and 6 d respectively after extraction of rat right mandibular molars. The right mandibular molars were used as control.

RESULTSBoth Nav1.8 and Nav1.9 mRNA in right trigeminal ganglion showed little change after 30 min, and increased slowly after 2 h. Nav1.8, Nav1.9 mRNA expressions increased by 27% and 24.5% respectively compared to the left trigeminal ganglion after 3 d, reaching the highest level (P < 0.05), and then the expressions began decreasing from 6 d.

CONCLUSIONSThe pain caused by molar extraction is related to the up-regulation of expressions of sodium channels protein Nav1.8 and Nav1.9 mRNA, indicating the participation of sodium channels in regulations of peripheral tissue pain after molar extraction.

Animals ; Male ; NAV1.8 Voltage-Gated Sodium Channel ; NAV1.9 Voltage-Gated Sodium Channel ; Neuropeptides ; metabolism ; Pain, Postoperative ; metabolism ; RNA, Messenger ; genetics ; Rats ; Rats, Wistar ; Sodium Channels ; metabolism ; Tooth Extraction ; Trigeminal Ganglion ; metabolism

OBJECTIVETo explore the effect of soy isoflavone on obesity in the light of hypothalamus and peripheral orexigenic gene regulation.

METHODSFifty-four female rats were randomly assigned to 6 groups: one sham-operated group (SHAM), one ovariectomized (OVX) control group, three OVX groups fed with 400 ppm (L-SI), 1200 ppm (M-SI) and 3600 ppm (H-SI) isoflavone respectively, and one OVX group receiving 0.45 ppm diethylstilbestrol (EC). All rats were allowed to take high-fat diet for 4 weeks. Some neuropeptides were measured by RT-PCR. These neuropeptides included NPY, pro-opiomelanocortin (POMC), cocaine and amphetamine regulated transcript (CART), orexin, melanin-concentrating hormone (MCH), melanin-concentrating hormone precursor (P-MCH), ghrelin, and leptin.

RESULTSCompared with the OVX control group, the body weight and food intake in the H-SI group were reduced significantly and there was a significant dose-dependent manner in the 3 isoflavone groups. The results of RT-PCR showed that the NPY level in the 3 isoflavone groups was significantly increased and the POMC/CART gene expression decreased significantly in rats' hypothalamus compared with that in the OVX control group. However, the expression of orexin, MCH and P-MCH had no change. The peripheral grelin mRNA expression was higher in the 3 isoflavone groups, while leptin gene expression in the fat was not consistent.

CONCLUSIONSThis research showed that isoflavone could prevent obesity induced by high-fat diet and ovariectomy through regulating hypothalamus and peripheral orexigenic gene expressions associated with food intake.

Animals ; Dietary Fats ; pharmacology ; Feeding Behavior ; drug effects ; physiology ; Female ; Gene Expression Regulation ; drug effects ; Hypothalamus ; Isoflavones ; chemistry ; pharmacology ; Neuropeptides ; genetics ; metabolism ; Obesity ; Ovariectomy ; RNA, Messenger ; genetics ; metabolism ; Rats ; Soybeans ; chemistry

Neural stem cells (NSCs) have been suggested as a groundbreaking solution for stroke patients because they have the potential for self-renewal and differentiation into neurons. The differentiation of NSCs into neurons is integral for increasing the therapeutic efficiency of NSCs during inflammation. Apoptosis signal-regulating kinase 1 (ASK1) is preferentially activated by oxidative stress and inflammation, which is the fundamental pathology of brain damage in stroke. ASK1 may be involved in the early inflammation response after stroke and may be related to the differentiation of NSCs because of the relationship between ASK1 and the p38 mitogen-activated protein kinase pathway. Therefore, we investigated whether ASK1 is linked to the differentiation of NSCs under the context of inflammation. On the basis of the results of a microarray analysis, we performed the following experiments: western blot analysis to confirm ASK1, DCX, MAP2, phospho-p38 expression; fluorescence-activated cell sorting assay to estimate cell death; and immunocytochemistry to visualize and confirm the differentiation of cells in brain tissue. Neurosphere size and cell survival were highly maintained in ASK1-suppressed, lipopolysaccharide (LPS)-treated brains compared with only LPS-treated brains. The number of positive cells for MAP2, a neuronal marker, was lower in the ASK1-suppressed group than in the control group. According to our microarray data, phospho-p38 expression was inversely linked to ASK1 suppression, and our immunohistochemistry data showed that slight upregulation of ASK1 by LPS promoted the differentiation of endogenous, neuronal stem cells into neurons, but highly increased ASK1 levels after cerebral ischemic damage led to high levels of cell death. We conclude that ASK1 is regulated in response to the early inflammation phase and regulates the differentiation of NSCs after inflammatory-inducing events, such as ischemic stroke.
Animals ; Cell Death ; Infarction, Middle Cerebral Artery/*metabolism ; Lipopolysaccharides/pharmacology ; MAP Kinase Kinase Kinase 5/genetics/*metabolism ; Male ; Mice ; Mice, Inbred C57BL ; Microtubule-Associated Proteins/genetics/metabolism ; Neural Stem Cells/cytology/drug effects/*metabolism ; *Neurogenesis ; Neuropeptides/genetics/metabolism ; p38 Mitogen-Activated Protein Kinases/genetics/metabolism