scholarly journals Effect of hyperoxic exposure during early development on neurotrophin expression in the carotid body and nucleus tractus solitarii

2012 ◽  
Vol 112 (10) ◽  
pp. 1762-1772 ◽  
Author(s):  
Raul Chavez-Valdez ◽  
Ariel Mason ◽  
Ana R. Nunes ◽  
Frances J. Northington ◽  
Clarke Tankersley ◽  
...  
Keyword(s):  
Protein Expression ◽  
Carotid Body ◽  
Acute Hypoxia ◽  
Synaptic Activity ◽  
Nucleus Tractus Solitarii ◽  
Mrna Levels ◽  
Bdnf Mrna ◽  
Rat Pups ◽  
Hyperoxic Exposure ◽  
And Shifts

Synaptic activity can modify expression of neurotrophins, which influence the development of neuronal circuits. In the newborn rat, early hyperoxia silences the synaptic activity and input from the carotid body, impairing the development and function of chemoreceptors. The purpose of this study was to determine whether early hyperoxic exposure, sufficient to induce hypoplasia of the carotid body and decrease the number of chemoafferents, would also modify neurotrophin expression within the nucleus tractus solitarii (nTS). Rat pups were exposed to hyperoxia (fraction of inspired oxygen 0.60) or normoxia until 7 or 14 days of postnatal development (PND). In the carotid body, hyperoxia decreased brain-derived neurotrophic factor (BDNF) protein expression by 93% ( P = 0.04) after a 7-day exposure, followed by a decrease in retrogradely labeled chemoafferents by 55% ( P = 0.004) within the petrosal ganglion at 14 days. Return to normoxia for 1 wk after a 14-day hyperoxic exposure did not reverse this effect. In the nTS, hyperoxia for 7 days: 1) decreased BDNF gene expression by 67% and protein expression by 18%; 2) attenuated upregulation of BDNF mRNA levels in response to acute hypoxia; and 3) upregulated p75 neurotrophic receptor, truncated tropomyosin kinase B (inactive receptor), and cleaved caspase-3. These effects were not observed in the locus coeruleus (LC). Hyperoxia for 14 days also decreased tyrosine hydroxylase levels by 18% ( P = 0.04) in nTS but not in the LC. In conclusion, hyperoxic exposure during early PND reduces neurotrophin levels in the carotid body and the nTS and shifts the balance of neurotrophic support from prosurvival to proapoptotic in the nTS, the primary brain stem site for central integration of sensory and autonomic inputs.

scholarly journals A possible role for hypoxia-induced apelin expression in enteric cell proliferation

2008 ◽  
Vol 294 (6) ◽  
pp. R1832-R1839 ◽  
Author(s):  
Song Han ◽  
Guiyun Wang ◽  
Xiang Qi ◽  
Heung M. Lee ◽  
Ella W. Englander ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Epithelial Cell ◽  
Intestinal Inflammation ◽  
Acute Hypoxia ◽  
Hypoxia Inducible Factor ◽  
Mrna Levels ◽  
Epithelial Cell Proliferation ◽  
Gi Tract ◽  
Rat Pups

Apelin is the endogenous ligand for the APJ receptor, and apelin and APJ are expressed in the gastrointestinal (GI) tract. Intestinal inflammation increases intestinal hypoxia-inducible factor (HIF) and apelin expression. Hypoxia and inflammation are closely linked cellular insults. The purpose of these studies was to investigate the influence of hypoxia on enteric apelin expression. Exposure of rat pups to acute hypoxia increased hepatic, stomach-duodenal, and colonic apelin mRNA levels 10-, 2-, and 2-fold, respectively ( P < 0.05 vs. controls). Hypoxia also increased colonic APJ mRNA levels, and apelin treatment during hypoxia exposure enhanced colonic APJ mRNA levels further. In vitro hypoxia also increased apelin and APJ mRNA levels. The hypoxia-induced elevation in apelin expression is most likely mediated by HIF, since HIF-activated apelin transcriptional activity is dependent on an intact, putative HIF binding site in the rat apelin promoter. Acute exposure of rat pups to hypoxia lowered gastric and colonic epithelial cell proliferation; hypoxia in combination with apelin treatment increased epithelial proliferation by 50%. In vitro apelin treatment of enteric cells exposed to hypoxia increased cell proliferation. Apelin treatment during normoxia was ineffective. Our studies imply that the elevation in apelin expression during hypoxia and inflammation in the GI tract functions in part to stimulate epithelial cell proliferation.

Hyperoxia enhances brain-derived neurotrophic factor and tyrosine kinase B receptor expression in peribronchial smooth muscle of neonatal rats

2005 ◽  
Vol 289 (2) ◽  
pp. L307-L314 ◽  
Author(s):  
Qin Yao ◽  
Musa A. Haxhiu ◽  
Syed I. Zaidi ◽  
Shijian Liu ◽  
Anjum Jafri ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Neurotrophic Factor ◽  
Brain Derived Neurotrophic Factor ◽  
Airway Hyperreactivity ◽  
Receptor Expression ◽  
Postnatal Life ◽  
Bdnf Mrna ◽  
Protein Levels ◽  
Rat Pups ◽  
Hyperoxic Exposure

Airway hyperreactivity is one of the hallmarks of hyperoxic lung injury in early life. As neurotrophins such as brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) are potent mediators of neuronal plasticity, we hypothesized that neurotrophin levels in the pulmonary system may be disturbed by hyperoxic exposure. We therefore evaluated the effects of hyperoxia on the expression of BDNF, NGF, and their corresponding high-affinity receptors, TrkB and TrkA, respectively, in the lung of rat pups. Five-day-old Sprague-Dawley rat pups were randomized to hyperoxic or control groups and then continuously exposed to hyperoxia (>95% oxygen) or normoxia over 7 days. At both mRNA and protein levels, BDNF was detected in lung but not in trachea; its level was substantially enhanced in lungs from the hyperoxia-exposed rat pups. Distribution of BDNF mRNA by in situ hybridization indicates that peribronchial smooth muscle was the major source of increased BDNF production in response to hyperoxic exposure. Interestingly, hyperoxia-induced elevation of BDNF was not accompanied by any changes of NGF levels in lung. Furthermore, hyperoxic exposure increased the expression of TrkB in peribronchial smooth muscle but had no effect on the distribution of the specific NGF receptor TrkA. These findings indicate that hyperoxic stress not only upregulates BDNF at mRNA and protein levels but also enhances TrkB within peribronchial smooth muscle. However, there was no corresponding effect on NGF and TrkA receptors. We speculate that the increased level of BDNF may contribute to hyperoxia-induced airway hyperresponsiveness in early postnatal life.

Hyperoxic exposure of developing rat lung decreases tropoelastin mRNA levels that rebound postexposure

1993 ◽  
Vol 265 (3) ◽  
pp. L293-L300 ◽  
Author(s):  
M. C. Bruce ◽  
E. N. Bruce ◽  
K. Janiga ◽  
A. Chetty
Keyword(s):  
Elastic Fiber ◽  
Lung Parenchyma ◽  
Regulatory Control ◽  
Separate Experiment ◽  
Elastic Fibers ◽  
Mrna Levels ◽  
Fiber Assembly ◽  
Total Length ◽  
Rat Pups ◽  
Hyperoxic Exposure

These studies were undertaken to determine whether tropoelastin message expression in lung parenchymal tissue is altered in rats reared in an hyperoxic environment during the period of time that alveolar septation normally occurs. Rat pups were exposed to > 95% oxygen from days 4 to 14 and killed during the exposure and recovery periods. Results of in situ hybridizations indicated a delay in peak tropoelastin (TE) message levels in oxygen-exposed rats vs. controls, day 16 vs. day 11, respectively. In addition, lung parenchymal TE mRNA levels in the oxygen-exposed pups remained elevated through day 23, 1 wk after TE mRNA levels had decreased in controls. These observations suggest that the regulatory control of elastin synthesis during lung alveolar septation is altered by hyperoxic exposure. In a separate experiment, rat pups were exposed to > 95% oxygen during the period of alveolarization and followed for 4 wk postexposure. Pulmonary function measurements were conducted to determine whether lung function was altered postexposure and, if so, whether recovery occurred. We also used stereological techniques to quantitate the total length of lung parenchymal elastic fibers to determine whether elastic fiber content in the oxygen-exposed pups was restored to normal levels during the month postexposure. Although the total length of elastic fibers in lung parenchyma was found to be greater in oxygen-exposed than control pups from postnatal days 22 to 41, pressure-volume curves indicated that lungs of the oxygen-exposed pups tended to be more compliant than controls, suggesting that abnormal elastic fiber assembly might have been a contributing factor.

MiR-493 Induces Cytotoxic Autophagy in Prostate Cancer Cells through Regulation on PHLPP2

2020 ◽  
Vol 21 (14) ◽  
pp. 1451-1456 ◽  
Author(s):  
Jun Deng ◽  
Ming Ma ◽  
Wei Jiang ◽  
Liangliang Zheng ◽  
Suping Cui
Keyword(s):  
Prostate Cancer ◽  
Protein Expression ◽  
Cell Function ◽  
Mrna Levels ◽  
Prostate Cancer Cells ◽  
Potent Inducer ◽  
Qrt Pcr ◽  
Autophagy Gene ◽  
The Relationship ◽  
Cancer Inhibition

Background: MiR-493 promotes the proliferation of prostate cancer (PC) cells by targeting PHLPP2. We aimed to explore the relationship between miR-493 and autophagy in PC. Methods: qRT-PCR and western blotting were used to determine the mRNA levels and protein expression of miR-493, PHLPP2, autophagy gene BECN1 and ATG7 in PC cells. The autophagy gene expression was determined after PC cells transfected with miR-493 precursor or PHLPP2 precursor. Corresponding changes of autophagy phenotype and PC cell function were also studied. Results: The mRNA levels and protein expression of miR-493, PHLPP2, BECN1 and ATG7 in PC cells were significantly decreased in PC cells. Overexpression of miR-493 or PHLPP2 markedly upregulated the expression levels of BECN1 and ATG7 in PC cells. Overexpression of miR-493 and PHLPP2 markedly promoted autophagy, and inhibited the invasion and cloning formation of PC cells. Conclusion: MiR-493 is a potent inducer of cytotoxic autophagy that leads to prostate cancer inhibition by regulating on PHLPP2.

Effect of prenatal isoxsuprine on pulmonary oxygen toxicity in the newborn rat

1980 ◽  
Vol 48 (3) ◽  
pp. 505-510 ◽  
Author(s):  
L. Frank ◽  
J. Summerville ◽  
D. Massaro
Keyword(s):  
Enzyme Activities ◽  
Oxygen Toxicity ◽  
Fetal Lung ◽  
Antioxidant Enzyme Activities ◽  
Newborn Rats ◽  
Lung Maturation ◽  
Lung Weight ◽  
Pregnant Rats ◽  
Rat Pups ◽  
Hyperoxic Exposure

Isoxsuprine, a beta-sympathomimetic agent used clinically to delay premature parturition and to possibly accelerate fetal lung maturation, was administered to pregnant rats at 48 and 24 h prior to delivery. Newborn rats were placed in 96-98% O2 (or room air) to determine if the prenatal isoxsuprine treatment compromised their tolerance to prolonged hyperoxic exposure. (Exogenous catecholamines are known to exacerbate O2 toxicity in adult animals). Survival of the isoxsuprine-treated pups in O2 (52%) was no different than for control neonates exposed to hyperoxia for 7 days (57%) (P = 0.22). Body weight, lung weight, lung protein, and DNA content of the newborns were also not altered by the prenatal isoxsuprine treatment. Lung antioxidant enzyme activities for superoxide dismutase, catalase, and glutathione peroxidase were the same at birth in the isoxsuprine-treated and control rat pups, and the enzyme activities increased in response to hyperoxic exposure in each group to an equivalent degree. Thus, in utero treatment with isoxsuprine had no apparent adverse effect on newborn rats exposed to a prolonged O2 challenge.

Very Early Exercise Rehabilitation After Intracerebral Hemorrhage Promotes Inflammation in the Brain

2021 ◽  
pp. 154596832110063
Author(s):  
Keigo Tamakoshi ◽  
Madoka Maeda ◽  
Shinnosuke Nakamura ◽  
Nae Murohashi
Keyword(s):  
Intracerebral Hemorrhage ◽  
Protein Expression ◽  
Brain Regions ◽  
Motor Dysfunction ◽  
Inflammatory Factors ◽  
Mrna Levels ◽  
Exercise Rehabilitation ◽  
Early Exercise ◽  
Polymerase Chain ◽  
To Receive

Background Very early exercise has been reported to exacerbate motor dysfunction; however, its mechanism is largely unknown. Objective This study examined the effect of very early exercise on motor recovery and associated brain damage following intracerebral hemorrhage (ICH) in rats. Methods Collagenase solution was injected into the left striatum to induce ICH. Rats were randomly assigned to receive placebo surgery without exercise (SHAM) or ICH without (ICH) or with very early exercise within 24 hours of surgery (ICH+VET). We observed sensorimotor behaviors before surgery, and after surgery preexercise and postexercise. Postexercise brain tissue was collected 27 hours after surgery to investigate the hematoma area, brain edema, and Il1b, Tgfb1, and Igf1 mRNA levels in the striatum and sensorimotor cortex using real-time reverse transcription polymerase chain reaction. NeuN, PSD95, and GFAP protein expression was analyzed by Western blotting. Results We observed significantly increased skillful sensorimotor impairment in the horizontal ladder test and significantly higher Il1b mRNA levels in the striatum of the ICH+VET group compared with the ICH group. NeuN protein expression was significantly reduced in both brain regions of the ICH+VET group compared with the SHAM group. Conclusion Our results suggest that very early exercise may be associated with an exacerbation of motor dysfunction because of increased neuronal death and region-specific changes in inflammatory factors. These results indicate that implementing exercise within 24 hours after ICH should be performed with caution.

scholarly journals Altered mRNA Levels of Stress-Related Peptides in Mouse Hippocampus and Caudate-Putamen in Withdrawal after Long-Term Intermittent Exposure to Tobacco Smoke or Electronic Cigarette Vapour

2021 ◽  
Vol 22 (2) ◽  
pp. 599
Author(s):  
Lucia Carboni ◽  
Luisa Ponzoni ◽  
Daniela Braida ◽  
Mariaelvina Sala ◽  
Cecilia Gotti ◽  
...  
Keyword(s):  
Public Health Problem ◽  
Mrna Levels ◽  
Obsessive Compulsive ◽  
Bdnf Mrna ◽  
Object Recognition Test ◽  
Caudate Putamen ◽  
Molecular Alterations ◽  
Marble Burying ◽  
Cigarette Withdrawal

Nicotine addiction is a severe public health problem. The aim of this study was to investigate the alterations in key neurotransmissions after 60 days of withdrawal from seven weeks of intermittent cigarette smoke, e-cigarette vapours, or an e-cigarette vehicle. In the nicotine withdrawal groups, increased depressive and anxiety/obsessive–compulsive-like behaviours were demonstrated in the tail suspension, sucrose preference and marble burying tests. Cognitive impairments were detected in the spatial object recognition test. A significant increase in Corticotropin-releasing factor (Crf) and Crf1 mRNA levels was observed, specifically after cigarette withdrawal in the caudate-putamen nucleus (CPu). The nociceptin precursor levels were reduced by cigarette (80%) and e-cigarette (50%) withdrawal in the CPu. The delta opioid receptor showed a significant reduction in the hippocampus driven by the exposure to an e-cigarette solubilisation vehicle, while the mRNA levels doubled in the CPu of mice that had been exposed to e-cigarettes. Withdrawal after exposure to e-cigarette vapour induced a 35% Bdnf mRNA decrease in the hippocampus, whereas Bdnf was augmented by 118% by cigarette withdrawal in the CPu. This study shows that long-term withdrawal-induced affective and cognitive symptoms associated to lasting molecular alterations in peptidergic signalling may determine the impaired neuroplasticity in the hippocampal and striatal circuitry.

Hepatocellular expression of glucose-6-phosphatase is unaltered during hepatic regeneration

1998 ◽  
Vol 275 (4) ◽  
pp. G717-G722 ◽  
Author(s):  
Wisam F. Zakko ◽  
Carl L. Berg ◽  
John L. Gollan ◽  
Richard M. Green
Keyword(s):  
Gene Expression ◽  
Enzyme Activity ◽  
Protein Expression ◽  
Partial Hepatectomy ◽  
Initial Phase ◽  
Physiological Function ◽  
Liver Homogenate ◽  
Hepatic Regeneration ◽  
Mrna Levels ◽  
Microsomal Enzyme

Gluconeogenesis and glycogenolysis are essential hepatic functions required for glucose homeostasis. During the initial phase of hepatic regeneration, the immediate-early genes (IEG) are rapidly expressed, and the IEG RL-1 encodes for glucose-6-phosphatase (G-6- Pase). G-6- Pase is a microsomal enzyme essential for gluconeogenesis and glycogenolysis. This study employs a partial-hepatectomy model to examine the expression and activity of G-6- Pase. After partial hepatectomy, rat hepatic G-6- Pase gene expression is transcriptionally regulated, and mRNA levels are increased ≈30-fold. However, in contrast to this rapid gene induction, microsomal enzyme activity is unchanged after partial hepatectomy. Western blotting demonstrates that microsomal G-6- Pase protein expression is also unchanged after partial hepatectomy, and similar results are also noted in whole liver homogenate. Thus, despite marked induction in gene expression of the IEG G-6- Pase after partial hepatectomy, protein expression and enzyme activity remain unchanged. These data indicate that, although this hepatocyte IEG is transcriptionally regulated, the physiologically important level of regulation is posttranscriptional. This highlights the importance of correlating gene expression of IEG with protein expression and physiological function.

Acute O2 sensing through HIF2α-dependent expression of atypical cytochrome oxidase subunits in arterial chemoreceptors

2019 ◽  
Vol 13 (615) ◽  
pp. eaay9452 ◽  
Author(s):  
Alejandro Moreno-Domínguez ◽  
Patricia Ortega-Sáenz ◽  
Lin Gao ◽  
Olalla Colinas ◽  
Paula García-Flores ◽  
...  
Keyword(s):  
Ion Channels ◽  
Carotid Body ◽  
Acute Hypoxia ◽  
Mechanistic Explanation ◽  
Nerve Fibers ◽  
Adaptive Responses ◽  
Glomus Cells ◽  
Adult Mice ◽  
Genes Encoding ◽  
Regulation Of Breathing

Acute cardiorespiratory responses to O2 deficiency are essential for physiological homeostasis. The prototypical acute O2-sensing organ is the carotid body, which contains glomus cells expressing K+ channels whose inhibition by hypoxia leads to transmitter release and activation of nerve fibers terminating in the brainstem respiratory center. The mechanism by which changes in O2 tension modulate ion channels has remained elusive. Glomus cells express genes encoding HIF2α (Epas1) and atypical mitochondrial subunits at high levels, and mitochondrial NADH and reactive oxygen species (ROS) accumulation during hypoxia provides the signal that regulates ion channels. We report that inactivation of Epas1 in adult mice resulted in selective abolition of glomus cell responsiveness to acute hypoxia and the hypoxic ventilatory response. Epas1 deficiency led to the decreased expression of atypical mitochondrial subunits in the carotid body, and genetic deletion of Cox4i2 mimicked the defective hypoxic responses of Epas1-null mice. These findings provide a mechanistic explanation for the acute O2 regulation of breathing, reveal an unanticipated role of HIF2α, and link acute and chronic adaptive responses to hypoxia.

scholarly journals Sesamin Modulates Tyrosine Hydroxylase, Superoxide Dismutase, Catalase, Inducible No Synthase and Interleukin-6 Expression in Dopaminergic Cells Under Mpp+-Induced Oxidative Stress

2008 ◽  
Vol 1 (1) ◽  
pp. 54-62 ◽  
Author(s):  
Vicky Lahaie-Collins ◽  
Julie Bournival ◽  
Marilyn Plouffe ◽  
Julie Carange ◽  
Maria-Grazia Martinoli
Keyword(s):  
Oxidative Stress ◽  
Superoxide Dismutase ◽  
Tyrosine Hydroxylase ◽  
Protein Expression ◽  
Pc12 Cells ◽  
Interleukin 6 ◽  
Estrogen Receptor Alpha ◽  
Strong Increase ◽  
Mrna Levels ◽  
Neuronal Pc12 Cells

Oxidative stress is regarded as a mediator of nerve cell death in several neurodegenerative disorders, such as Parkinson's disease. Sesamin, a lignan mainly found in sesame oil, is currently under study for its anti-oxidative and possible neuroprotective properties. We used 1-methyl-4-phenyl-pyridine (MPP+) ion, the active metabolite of the potent parkinsonism-causing toxin 1-methyl-4-phenyl-1,2,5,6-tetrahydropyridine, to produce oxidative stress and neurodegeneration in neuronal PC12 cells, which express dopamine, as well as neurofilaments. Our results show that picomolar doses of sesamin protected neuronal PC12 cells from MPP+-induced cellular death, as revealed by colorimetric measurements and production of reactive oxygen species. We also demonstrated that sesamin acted by rescuing tyrosine hydroxylase levels from MPP+-induced depletion. Sesamin, however, did not modulate dopamine transporter levels, and estrogen receptor-alpha and -beta protein expression. By examining several parameters of cell distress, we found that sesamin also elicited a strong increase in superoxide dismutase activity as well as protein expression and decreased catalase activity and the MPP+stimulated inducible nitric oxide synthase protein expression, in neuronal PC12 cells. Finally, sesamin possessed significant anti-inflammatory properties, as disclosed by its potential to reduce MPP+-induced interleukin-6 mRNA levels in microglia. From these studies, we determined the importance of the lignan sesamin as a neuroprotective molecule and its possible role in complementary and/or preventive therapies of neurodegenerative diseases.

Sign in / Sign up

Export Citation Format

Share Document