Increase in peripheral oxidative stress during hypercholesterolemia is not reflected in the central nervous system: evidence from two mouse models

2005 ◽  
Vol 46 (6) ◽  
pp. 435-439 ◽  
Author(s):  
Tao Ding ◽  
Yeumang Yao ◽  
Domenico Praticò
Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1372
Author(s):  
Tengrui Shi ◽  
Jianxi Song ◽  
Guanying You ◽  
Yujie Yang ◽  
Qiong Liu ◽  
...  

MsrB1 used to be named selenoprotein R, for it was first identified as a selenocysteine containing protein by searching for the selenocysteine insert sequence (SECIS) in the human genome. Later, it was found that MsrB1 is homologous to PilB in Neisseria gonorrhoeae, which is a methionine sulfoxide reductase (Msr), specifically reducing L-methionine sulfoxide (L-Met-O) in proteins. In humans and mice, four members constitute the Msr family, which are MsrA, MsrB1, MsrB2, and MsrB3. MsrA can reduce free or protein-containing L-Met-O (S), whereas MsrBs can only function on the L-Met-O (R) epimer in proteins. Though there are isomerases existent that could transfer L-Met-O (S) to L-Met-O (R) and vice-versa, the loss of Msr individually results in different phenotypes in mice models. These observations indicate that the function of one Msr cannot be totally complemented by another. Among the mammalian Msrs, MsrB1 is the only selenocysteine-containing protein, and we recently found that loss of MsrB1 perturbs the synaptic plasticity in mice, along with the astrogliosis in their brains. In this review, we summarized the effects resulting from Msr deficiency and the bioactivity of selenium in the central nervous system, especially those that we learned from the MsrB1 knockout mouse model. We hope it will be helpful in better understanding how the trace element selenium participates in the reduction of L-Met-O and becomes involved in neurobiology.


Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Srinivas Sriramula ◽  
Huijing Xia ◽  
Eric Lazartigues

Elevated reactive oxygen species (ROS) in the central nervous system (CNS) through NADPH oxidase and diminished Nitric oxide (NO) levels are involved in the pathogenesis of hypertension. We previously reported that central Angiotensin Converting Enzyme 2 (ACE2) overexpression prevents the development of hypertension induced by DOCA-salt in a transgenic mouse model (syn-hACE2; SA) with human ACE2 targeted selectively to neurons in the CNS. While baseline blood pressure (BP; telemetry) was not different among genotypes, DOCA-salt treatment (1mg/g body wt DOCA, 1% saline in drinking water for 3 weeks) resulted in significantly lower BP level in SA mice (122 ±3 mmHg, n=12) compared to non-transgenic (NT) littermates (138 ±3 mmHg, n=8). To elucidate the mechanisms involved in this response, we investigated the paraventricular nucleus (PVN) expression of Nox-2 (catalytic subunit of NADPH oxidase), 3-nitrotyrosine, and endothelial nitric oxide synthase (eNOS) and anti-oxidant enzymes superoxide dismutase (SOD) and catalase in the hypothalamus. DOCA-salt treatment resulted in decreased catalase (95.2 ±5.6 vs. 113.8 ±17.6 mmol/min/ml, p<0.05) and SOD (4.1 ±0.4 vs. 5.9 ±0.2 U/ml, p<0.01) activities in hypothalamic homogenates of NT mice, which was prevented by ACE2 overexpression (141.8 ±9.9 vs. 142.1 ±9.2 mmol/min/ml and 5.9 ±0.3 vs. 7.9 ±0.2 U/ml, respectively). NT mice treated with DOCA-salt showed increased oxidative stress as indicated by increased expression of Nox-2 (61 ±5 % increase, n=9, p<0.001 vs. NT) and 3-nitrotyrosine (89 ±32 % increase, n=9, p<0.01 vs. NT) in the PVN which was attenuated in SA mice. Furthermore, DOCA-salt hypertension resulted in decreased phosphorylation of eNOS-ser1177 in the PVN (33 ±5 % decrease, n=9, p<0.05 vs NT) and this decrease was prevented by ACE2 overexpression. Taken together, these data provide evidence that brain ACE2 regulates the balance between NO and ROS levels, thereby preventing the development of DOCA-salt hypertension.


1997 ◽  
Vol 52 (4) ◽  
pp. 261-281 ◽  
Author(s):  
Stefan Peuchen ◽  
Juan P. Bolaños ◽  
Simon J.R. Heales ◽  
Angeles Almeida ◽  
Michael R. Duchen ◽  
...  

2014 ◽  
Vol 24 ◽  
pp. S268-S269
Author(s):  
E. Brito Cortez Lima ◽  
C.N. Soares de Sousa ◽  
L. Nascimento Meneses ◽  
N. Coelho Ximenes ◽  
P. Jonas Gonçalves Maia ◽  
...  

2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Genaro G. Ortiz ◽  
Fermín P. Pacheco-Moisés ◽  
Oscar K. Bitzer-Quintero ◽  
Ana C. Ramírez-Anguiano ◽  
Luis J. Flores-Alvarado ◽  
...  

Multiple sclerosis (MS) exhibits many of the hallmarks of an inflammatory autoimmune disorder including breakdown of the blood-brain barrier (BBB), the recruitment of lymphocytes, microglia, and macrophages to lesion sites, the presence of multiple lesions, generally being more pronounced in the brain stem and spinal cord, the predominantly perivascular location of lesions, the temporal maturation of lesions from inflammation through demyelination, to gliosis and partial remyelination, and the presence of immunoglobulin in the central nervous system and cerebrospinal fluid. Lymphocytes activated in the periphery infiltrate the central nervous system to trigger a local immune response that ultimately damages myelin and axons. Pro-inflammatory cytokines amplify the inflammatory cascade by compromising the BBB, recruiting immune cells from the periphery, and activating resident microglia. inflammation-associated oxidative burst in activated microglia and macrophages plays an important role in the demyelination and free radical-mediated tissue injury in the pathogenesis of MS. The inflammatory environment in demyelinating lesions leads to the generation of oxygen- and nitrogen-free radicals as well as proinflammatory cytokines which contribute to the development and progression of the disease. Inflammation can lead to oxidative stress and vice versa. Thus, oxidative stress and inflammation are involved in a self-perpetuating cycle.


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