Age modulates the nitric oxide system response in the ischemic cerebellum

A multidimensional sight on cardiac failure: uncovered from structural to molecular level

Heart failure is one of the leading causes of death, with high mortality rate within 5 years after diagnosis. Treatment and prognosis options for heart failure primarily targeted on hemodynamic and neurohumoral components that drive progressive deterioration of the heart. However, given the multifactorial background that eventually leads to the "phenotype" named heart failure, better insight into the various components may lead to personalized treatment opportunities. Indeed, currently used criteria to diagnose and/or classify heart failure are possibly too focused on phenotypic improvement rather than the molecular driver of the disease and could therefore be further refined by integrating the leap of molecular and cellular knowledge. The ambiguity of the ejection fraction-based classification criteria became evident with development of advanced molecular techniques and the dawn of omics disciplines which introduced the idea that disease is caused by a myriad of cellular and molecular processes rather than a single event or pathway. The fact that different signaling pathways may underlie similar clinical manifestations calls for a more holistic study of heart failure. In this context, the systems biology approach can offer a better understanding of how different components of a system are altered during disease and how they interact with each other, potentially leading to improved diagnosis and classification of this condition. This review is aimed at addressing heart failure through a multilayer approach that covers individually some of the anatomical, morphological, functional, and tissue aspects, with focus on cellular and subcellular features as an alternative insight into new therapeutic opportunities.

The roles of methylenetetrahydrofolate reductase 677C>T and 1298A>C polymorphisms in moyamoya disease patients

PURPOSE

The methylenetetrahydrofolate reductase (MTHFR) 677C>T and 1298A>C polymorphisms, which are associated with hyperhomocysteinemia and nitric oxide (NO) deficiency (which is related to atherothrombosis and cerebral ischemia), have not been studied in moyamoya disease. A case-control study was performed to investigate whether the MTHFR 677C>T and 1298A>C polymorphisms contribute to moyamoya disease (MMD).

METHODS

One hundred and seven Korean patients with MMD (mean age, 20.85 ± 15.89 years; 66.4 % female) and 232 healthy control subjects (mean age, 23.99 ± 16.16 years; 56.8 % female) were included. Genotyping for the MTHFR 677C>T and 1298A>C polymorphisms and measurements of homocysteine, folate, vitamin B12, and NO in the cerebrospinal fluid (CSF) were performed. The statistical analysis was performed by multivariate linear regression and logistic regression.

RESULT

The MTHFR 677CT+TT genotype frequency was significantly increased with early-onset MMD (<10 years) compared with late-onset MMD (≥10 years) (adjusted odds ratio, 3.392; 95 % confidence interval, 1.294-8.893, P = 0.013). The MTHFR 677C-1298C/677T-1298A diplotype (1.71 ± 1.23 arbitrary units) presented significantly lower NO levels in the CSF compared with the 677C-1298A/677C-1298A diplotype (11.40 ± 12.24 arbitrary units).

CONCLUSION

The MTHFR 677C>T and 1298A>C polymorphisms have restricted roles in the Korean MMD population. Therefore, further studies involving larger and more heterogeneous cohorts are needed to extend our understanding of the influence of polymorphisms in MTHFR and other thrombophilic genes on MMD.

Differences in neuronal damage and gliosis in the hippocampus between young and adult gerbils induced by long duration of transient cerebral ischemia

Response to cerebral ischemia in young animals was very different from that in the adult. The aim of this study was to investigate differences in neuronal death and gliosis in the hippocampal CA1 region (CA1) between adult and young gerbils following 5 and 15 min of transient cerebral ischemia. Delayed neuronal death (DND) of pyramidal cells occurred in the CA1 was similar in all the adult gerbils after 5 and 15 min of ischemia: the DND occurred 4 days after ischemia. In the young groups, DND of pyramidal cells in the CA1 region occurred 7 and 3 days after 5 and 15 min of ischemia, respectively. On the other hand, the activation of GFAP-immunoreactive ((+)) astrocytes and Iba-1(+) microglia was different in the young groups from the adult groups after ischemia. The change pattern of GFAP immunoreactivity in the adult groups was similar in both the adult groups after ischemia; in the young groups, the activation of GFAP(+) astrocytes after 5 min of ischemia was much delayed than that after 15 min of ischemia. Activated Iba-1(+) microglia were aggregated in the stratum pyramidale 4 days after ischemia in all the adult ischemia-operated groups; in the young groups, activated Iba-1(+) microglia were aggregated in the stratum pyramidale 7 days after 5 min of ischemia and 3 days after 15 min of ischemia. These observations indicate that DND in young animals is very different from the adult according to different duration of transient cerebral ischemia and glial activation is very different in young animals after different duration of transient ischemia.

Comparison of glial activation in the hippocampal CA1 region between the young and adult gerbils after transient cerebral ischemia

It has been reported that young animals are less vulnerable to brain ischemia. In the present study, we compared gliosis in the hippocampal CA1 region of the young gerbil with those in the adult gerbil induced by 5 min of transient cerebral ischemia by immunohistochemistry and western blot for glial cells. We used male gerbils of postnatal month 1 (PM 1) as the young and PM 6 as the adult. Neuronal death in CA1 pyramidal neurons in the adult gerbil occurred at 4 days post-ischemia; the neuronal death in the young gerbil occurred at 7 days post-ischemia. The findings of glial changes in the young gerbil after ischemic damage were distinctively different from those in the adult gerbil. Glial fibrillary acidic protein-immunoreactive astrocytes, ionized calcium-binding adapter molecule (Iba-1), and isolectin B4-immunoreactive microglia in the ischemic CA1 region were activated much later in the young gerbil than in the adult gerbil. In brief, very less gliosis occurred in the hippocampal CA1 region of the young gerbil than in the adult gerbil after transient cerebral ischemia.

Age-specific eNOS polymorphisms in moyamoya disease

OBJECTIVE

We conducted a case-control study to investigate whether polymorphisms in eNOS are related to the age-specific onset of moyamoya disease.

MATERIALS AND METHODS

Ninety-three Korean patients [mean age, 23.0 ± 16.1 years; 59 female (63.4%) and 34 male (36.6%)] with moyamoya disease were consecutively recruited for this study. Three hundred twenty-eight healthy subjects [mean age, 27.7 ± 16.2 years; 217 female (66.2%), 111 male (33.8%)] were consecutively included in the control group. The subjects were divided into pediatric (< 20 years) and adult (≥ 20 years) groups. We further divided the moyamoya group into ischemic and hemorrhagic groups based on clinical and MRI findings. The frequencies and distributions of four eNOS polymorphisms (eNOS -922A>G, -786T>C, 4a4b, and 894G>T) were assessed in pediatric and adult patients with moyamoya disease and compared to the frequencies and distribution in the control group.

RESULTS

No differences in eNOS polymorphisms were observed between control and moyamoya disease group. However, we found that the 4a4b sequences was less frequent in the adult group (p = 0.029). Compared to the control group, there were differences in the haplotype distribution of the study group, specifically the A-4b-G haplotype, which was seen more frequently in the adult patient group.

CONCLUSION

Our results suggest that pediatric and adult-onset moyamoya disease have different genetic backgrounds. These genetic differences can affect age-specific clinical characteristics, such as cerebral ischemia and hemorrhage.

Study of the nitric oxide system in the rat cerebellum during aging

Background

The cerebellum is the neural structure with the highest levels of nitric oxide, a neurotransmitter that has been proposed to play a key role in the brain aging, although knowledge concerning its contribution to cerebellar senescence is still unclear, due mainly to absence of integrative studies that jointly evaluate the main factors involved in its cell production and function. Consequently, in the present study, we investigate the expression, location, and activity of nitric oxide synthase isoenzymes; the protein nitration; and the production of nitric oxide in the cerebellum of adult and old rats.

Results

Our results show no variation in the expression of nitric oxide synthase isoforms with aging, although, we have detected some changes in the cellular distribution pattern of the inducible isoform particularly in the cerebellar nuclei. There is also an increase in nitric oxide synthase activity, as well as greater protein-nitration levels, and maintenance of nitrogen oxides (NOx) levels in the senescent cerebellum.

Conclusions

The nitric oxide/nitric oxide syntahses system suffers from a number of changes, mainly in the inducible nitric oxide synthase distribution and in overall nitric oxide synthases activity in the senescent cerebellum, which result in an increase of the protein nitration. These changes might be related to the oxidative damage detected with aging in the cerebellum.