Roles of glutamate receptors in a novel in vitro model of early, comorbid cerebrovascular, and Alzheimer's diseases.

Systemic multimorbidity is highly prevalent in the elderly and, remarkably, coexisting neuropathological markers of Alzheimer's (AD) and cerebrovascular (CVD) diseases are found at autopsy in most brains of patients clinically diagnosed as AD. Little is known on neurodegeneration peculiar to comorbidities, especially at early stages when pathogenesis may propagate at subclinical levels. We developed a novel in vitro model of comorbid CVD/AD in organotypic hippocampal cultures, by combining oxygen-glucose deprivation (OGD) and exposure to amyloid-Aß oligomers (AßOs), both applied at levels subtoxic to neurons when used in isolation. We focused on synaptic proteins and the roles of glutamate receptors, which have been implicated in many basic and clinical approaches to either CVD or AD. Subtoxic insults by OGD and AßOs synergized to reduce levels of synaptophysin (SYP) and PSD-95 without cell death, while effects of antagonists of either metabotropic or ionotropic glutamate receptors were distinct from reports in models of isolated CVD or AD. In particular, modulation of glutamate receptors differentially impacted SYP and PSD-95, and antagonists of a single receptor subtype had distinct effects when either isolated or combined. Our findings highlight the complexity of CVD/AD comorbidity, help understand variable responses to glutamate receptor antagonists in patients diagnosed with AD and may contribute to future development of therapeutics based on investigation of the pattern of progressive comorbidity.

ACE2 Expression Is Increased in the Lungs of Patients With Comorbidities Associated With Severe COVID-19.

Patients who died from COVID-19 often had comorbidities, such as hypertension, diabetes, and chronic obstructive lung disease. Although angiotensin-converting enzyme 2 (ACE2) is crucial for SARS-CoV-2 to bind and enter host cells, no study has systematically assessed the ACE2 expression in the lungs of patients with these diseases. Here, we analyzed over 700 lung transcriptome samples from patients with comorbidities associated with severe COVID-19 and found that ACE2 was highly expressed in these patients compared to control individuals. This finding suggests that patients with such comorbidities may have higher chances of developing severe COVID-19. Correlation and network analyses revealed many potential regulators of ACE2 in the human lung, including genes related to histone modifications, such as HAT1, HDAC2, and KDM5B. Our systems biology approach offers a possible explanation for increased COVID-19 severity in patients with certain comorbidities.

Associations of Cerebrovascular Metabolism Genotypes With Neuropsychiatric Symptoms and Age at Onset of Alzheimer's Disease Dementia

Objective: To study associations of cerebrovascular metabolism genotypes and haplotypes with age at Alzheimer’s disease dementia (AD) onset and with neuropsychiatric symptoms according to each dementia stage. Methods: Consecutive outpatients with late-onset AD were assessed for age at dementia onset and Neuropsychiatric Inventory scores according to Clinical Dementia Rating scores, apolipoprotein E gene (APOE) haplotypes, angiotensin-converting enzyme gene (ACE) variants rs1800764 and rs4291, low-density lipoprotein cholesterol receptor gene (LDLR) variants rs11669576 and rs5930, cholesteryl ester transfer protein gene (CETP) variants I422V and TaqIB, and liver X receptor beta gene (NR1H2) polymorphism rs2695121. Results: Considering 201 patients, only APOE-ɛ4 carriers had earlier dementia onset in multiple correlations, as well as less apathy, more delusions, and more aberrant motor behavior. Both ACE polymorphisms were associated with less intense frontally mediated behaviors. Regarding LDLR variants, carriers of the A allele of rs11669576 had less anxiety and more aberrant motor behavior, whereas carriers of the A allele of rs5930 had less delusions, less anxiety, more apathy, and more irritability. CETP variants that included G alleles of I422V and TaqIB were mostly associated with less intense frontally mediated behaviors, while severely impaired carriers of the T allele of rs2695121 had more anxiety and more aberrant motor behavior. Conclusion: Though only APOE haplotypes affected AD onset, cerebrovascular metabolism genotypes were associated with differences in several neuropsychiatric manifestations of AD.

Associations of cerebrovascular metabolism genotypes with neuropsychiatric symptoms and age at onset of Alzheimer's disease dementia.

OBJECTIVE:: To study associations of cerebrovascular metabolism genotypes and haplotypes with age at Alzheimer's disease dementia (AD) onset and with neuropsychiatric symptoms according to each dementia stage. METHODS:: Consecutive outpatients with late-onset AD were assessed for age at dementia onset and Neuropsychiatric Inventory scores according to Clinical Dementia Rating scores, apolipoprotein E gene (APOE) haplotypes, angiotensin-converting enzyme gene (ACE) variants rs1800764 and rs4291, low-density lipoprotein cholesterol receptor gene (LDLR) variants rs11669576 and rs5930, cholesteryl ester transfer protein gene (CETP) variants I422V and TaqIB, and liver X receptor beta gene (NR1H2) polymorphism rs2695121. RESULTS:: Considering 201 patients, only APOE-ɛ4 carriers had earlier dementia onset in multiple correlations, as well as less apathy, more delusions, and more aberrant motor behavior. Both ACE polymorphisms were associated with less intense frontally mediated behaviors. Regarding LDLR variants, carriers of the A allele of rs11669576 had less anxiety and more aberrant motor behavior, whereas carriers of the A allele of rs5930 had less delusions, less anxiety, more apathy, and more irritability. CETP variants that included G alleles of I422V and TaqIB were mostly associated with less intense frontally mediated behaviors, while severely impaired carriers of the T allele of rs2695121 had more anxiety and more aberrant motor behavior. CONCLUSION:: Though only APOE haplotypes affected AD onset, cerebrovascular metabolism genotypes were associated with differences in several neuropsychiatric manifestations of AD.

Meta-analysis of TAFI polymorphisms and risk of cardiovascular and cerebrovascular diseases.

Cardiovascular and cerebrovascular diseases (CCVDs) are common and have high rates of morbidity, mortality, and recurrence. Thrombin-activatable fibrinolysis inhibitor (TAFI) is also known as carboxypeptidase B2 and is encoded by the CPB2 gene; CPB2 polymorphisms have been explored in a variety of studies, but their correlation to the risk of CCVDs remains ambiguous. We examined the hypothesized associations between CPB2 mutations and CCVDs in a general population. We searched, Embase, the Cumulative Index to Nursing and Allied Health Literature, the Science Citation Index, and several Chinese databases without applying any language restrictions. Nine case-control studies were analyzed in the current meta-analysis, and odds ratios (ORs) with their 95% confidence intervals were calculated. The pooled ORs indicated that the CPB2 rs3742264 G>A polymorphism was associated with an increased risk of CCVDs in the allele model (all P values < 0.05). A similar result for the CPB2 rs1926447 C>T polymorphism and CCVDs risk was detected in the allele model (P < 0.05). Ethnicity subgroup analysis implied that the rs3742264 G>A polymorphism was more likely to lead to the development of cerebrovascular disease in Asians (all P values < 0.05), whereas rs1926447 C>T was associated with cardiovascular disease among Africans (all P values < 0.05). These data suggest that the polymorphisms investigated, especially rs3742264 G>A and rs1926447 C>T, have a modest effect on susceptibility to CCVDs.

VKORC1 rs2359612 and rs9923231 polymorphisms correlate with high risks of cardiovascular and cerebrovascular diseases.

We aimed to confirm the correlations between rs2359612 and rs9923231 single nucleotide polymorphisms (SNPs) in the vitamin K epoxide reductase complex subunit 1 (VKORC1) gene and the risk of cardiovascular and cerebrovascular diseases (CCVDs) using meta-analysis. Electronic databases were exhaustively searched for relevant case-control studies by employing stringent inclusion and exclusion criteria. Manual retrieval was also conducted to obtain additional pertinent literature. The STATA statistical software was employed for the process of evidence synthesis. The initial literature search broadly identified 225 studies relevant to our topic of interest, and after multiple rounds of screening, 10 clinical case-control studies met the final inclusion criteria and were selected for this meta-analysis. The selected studies represented a combined total of 7329 patients with CCVD and 7951 healthy controls. Our meta-analysis demonstrated that the VKORC1 rs2359612 and rs9923231 SNPs were closely associated with high risk for CCVD (rs2359612: allelic: OR = 1.23, 95%CI = 1.00- 1.50, P = 0.047; dominant: OR = 1.32, 95%CI = 1.19-1.46, P < 0.001; rs9923231: allelic: OR = 0.74, 95%CI = 0.63-0.87, P < 0.001; dominant: OR = 0.67, 95%CI = 0.55-0.82, P < 0.001). Our meta-analysis provides strong evidence that two SNPs in the VKORC1 gene, rs2359612 and rs9923231, contribute to the risk of CCVD.

Genetic polymorphisms and cerebrovascular disease in children with sickle cell anemia from Rio de Janeiro, Brazil.

The aim of the present work was to examine possible genetic risk factors related to the occurrence of cerebrovascular disease (CVD) in Brazilian population, the frequency of ß(S)-globin gene haplotypes and co-inheritance with α-thalassemia (-α(3.7kb)) and single nucleotide polymorphism of methylenetetrahydrofolate reductase (MTHFR-C677T), Factor V Leiden (FV-G1691A) and prothrombin (PT-G20210A) genes in children from Rio de Janeiro. Ninety four children with sickle cell anemia (SCA) were included, 24 patients with cerebrovascular involvement and 70 patients without CVD as control group. The mean age of children at the time of the cerebrovascular event was similar to the control group. The frequency of -α(3.7kb) thalassemia was similar in both groups (p=0.751). Children with Bantu/Atypical ß(S)-globin gene haplotype presented 15 times more chance (OR=15.4 CI 95% 2.9-81.6) of CVD than the other ß(S)-globin gene haplotypes. The C677T polymorphism of MTHFR gene was similar in both groups (p=0.085). No mutation in the FV Leiden or PT genes was found. A large study seems necessary to establish the role of these genetic polymorphisms in Brazilian miscegenated population.

Genetic polymorphisms and cerebrovascular disease in children with sickle cell anemia from Rio de Janeiro, Brazil / Polimorfismos genéticos e doença cerebrovascular em crianças com anemia falciforme do Rio do Janeiro, Brasil

The aim of the present work was to examine possible genetic risk factors related to the occurrence of cerebrovascular disease (CVD) in Brazilian population, the frequency of βS-globin gene haplotypes and co-inheritance with α-thalassemia (-α3.7kb) and single nucleotide polymorphism of methylenetetrahydrofolate reductase (MTHFR-C677T), Factor V Leiden (FV-G1691A) and prothrombin (PT-G20210A) genes in children from Rio de Janeiro. Ninety four children with sickle cell anemia (SCA) were included, 24 patients with cerebrovascular involvement and 70 patients without CVD as control group. The mean age of children at the time of the cerebrovascular event was similar to the control group. The frequency of -α3.7kb thalassemia was similar in both groups (p=0.751). Children with Bantu/Atypical βS-globin gene haplotype presented 15 times more chance (OR=15.4 CI 95 percent 2.9-81.6) of CVD than the other βS-globin gene haplotypes. The C677T polymorphism of MTHFR gene was similar in both groups (p=0.085). No mutation in the FV Leiden or PT genes was found. A large study seems necessary to establish the role of these genetic polymorphisms in Brazilian miscegenated population.

Avaliar o papel da talassemia alfa (-α3.7kb), dos haplótipos da globina βS, e mutações nos genes da metileno-tetrahidrofolato redutase (MTHFR-C677T), fator V de Leiden (FV-G1691A) e protrombina (PT-G20210A) como fatores de risco para a doença cerebrovascular em pacientes com anemia falciforme. Foi realizado um estudo de caso controle com 94 crianças portadoras de anemia falciforme, 24 com doença cerebrovascular (DCV) e 70 sem DCV como grupo controle. A frequência de talassemia -α3.7kb foi semelhante em ambos os grupos (p=0,751). Crianças portadoras do haplótipo Bantu/Atípico da globina βS apresentam 15 vezes mais chances de desenvolverem DCV (OR=15,4 IC 95 por cento 2,9-81,6) do que os outros haplótipos. A frequência do polimorfismo MTHFR-C677T foi semelhante em ambos os grupos (p=0,085) e não foi observada mutação nos genes fator V e protrombina. Estudos com maior número de casos são necessários para esclarecer o papel desses polimorfismos genéticos na nossa população.

Coinheritance of α-thalassemia decreases the risk of cerebrovascular disease in a cohort of children with sickle cell anemia.

The study estimated α-thalassemia (α-thal) prevalence and assessed its associations with clinical and hematological features in a random sample of Brazilian children with sickle cell anemia (208 Hb SS and 13 Hb S-ß°-thal). α-Thalassemia genotyping was carried out by multiplex polymerase chain reaction (m-PCR) for seven alleles. Clinical and hematological data were retrieved from the 221 children's medical files. Their ages ranged from 2.5 to 10.4 years. Of the Hb SS children, 27.9% carried -α(3.7)/αα and 1.4% -α(3.7)/-α(3.7). The presence of α-thal was significantly associated with reduction in MCV, MCH, WBC values and reticulocyte counts. No significant association with blood transfusion or acute chest syndrome (ACS), was found. α-Thalassemia genotypes were strongly associated with reduction in risk for cerebrovascular disease (CVD) (conditional and abnormal transcranial Doppler or stroke; p = 0.007). The interaction of α-thal with other modulating factors should be investigated in order to define subphenotypes of the disease and to use them as clinical tools in the follow-up care of patients.

Comparative study of apolipoprotein-E polymorphism and plasma lipid levels in dyslipidemic and asymptomatic subjects, and their implication in cardio/cerebro-vascular disorders.

Polymorphisms in the apolipoprotein-E (apoE) gene may modulate lipoprotein metabolism at different steps and influence total and low density lipoprotein (LDL) cholesterol (LDLc) levels, as well as other lipid features. Population studies have documented significant differences in the frequency of apoE alleles which are related to the prevalence of various cardio-vascular and neuro-psychiatric diseases. In this study, the apoE genotypes and allele frequencies were analyzed in 216 individuals (109 dyslipidemic and 107 normo-lipidic subjects), and the relative contribution of apoE polymorphism on plasma lipid and lipoprotein levels, as well as risk factors was evaluated. In normo-lipidic volunteers, the frequencies of epsilon2, epsilon3 and epsilon4 alleles were 0.042, 0.832 and 0.126, while in dyslipidemic subjects 0.046, 0.835 and 0.119, respectively. No significant difference was observed among epsilon2, epsilon3 or epsilon4 and plasma lipid-lipoprotein levels in the dyslipidemic group. In normo-lipidemics, however, total cholesterol, LDLc and non-HDLc plasma levels were significantly lower in epsilon2 subjects when compared to epsilon3 and epsilon4 individuals. The allelic frequencies of apoE epsilon2, epsilon3 and epsilon4 were similar in dyslipidemic and normo-lipemic subjects, suggesting that apoE polymorphisms have no effect on plasma lipid-lipoprotein levels in dyslipidemic subjects. In contrast, in normo-lipemic subjects the epsilon2 allele showed to be associated with lower total cholesterol and LDLc levels, the mark of a better lipid profile. Depending on other co-existing factors, the epsilon2 allele, therefore, may play either a protective or pathogenic role. This elementary knowledge is a fundamental prerequisite for a possible diagnostic application of these lipoproteins as biomarkers to predict adverse cardio-vascular and/or neuro-psychiatric maladies.

Síndrome Herns (hereditaeria endoteliopatía con retinopatía, nefropatía y accidente cerebrovascular): reporte de un caso clínico / Herns syndrome (hereditary endotheliopathy with retinopathy, nephropathy and stroke): report of a clinic case

El Síndrome HERNS es una Vasculopatía de afectación multisistémica hereditaria autosómica dominante, cuya mutación se encuentra en el Cromosoma 3p21, se caracteriza por la afectación progresiva del endotelio, retina, riñón y accidente cerebrovascular, ha sido descrito en familias de origen caucásico principalmente y otras de origen oriental, el tratamiento y pronostico de estos pacientes no está del todo claro han habido reportes de mejoría en los síntomas y la progresión radiológica mediante el uso de corticoides, sin embargo la evidencia disponible no permite realizar conclusiones basadas en la evidencia debido al escaso numero de pacientes que se han reportado en la literatura. El diagnóstico se puede confirmar mediante estudio genético. Se presenta un caso de un paciente de 43 años que ingresa al Servicio de Urgencia con Síndrome Convulsivo, el primer estudio imagenológico reveló un probable Glioblastoma Multiforme su evolución y estudio evidenciaron compromiso multisistémico que comparte similitud clínica e imagenológicas en el test de Fuoresceína de Retina y la Resonancia Nuclear Magnética Cerebral con el Síndrome HERNS. El estudio molecular y genético no fue posible realizar quedando pendiente la confirmación diagnóstica.

The HERNS Syndrome is a Vasculopathy of affectation multisistemic hereditary autosomal dominant, whose mutation is in the Cromosoma 3p21, is characterized by the progressive affectation of the endotely, retinal, kidney and stroke, has been described in families of caucasian origin principally and others of oriental origin, the treatment and I predict of these patients it is not completely clear there have been reports of improvement in the symptoms and the radiological progression by means of the use of corticoides, nevertheless the available evidence does not allow to realize conclusions based on the evidence due to the patients' scanty number that has been reported in the literature. The diagnosis can be confirmed by means of genetic study. There appears a case of a patient of 43 years old who enters to the Service of Urgency with Convulsive Syndrome, the first radiological study revealed a probable Glioblastoma Multiforme his evolution and study they demonstrated commitment multisistemic that shares clinical similarity and imagenological in Fluoresceína's test of Retina and the Nuclear Magnetic Cerebral Resonance with the Syndrome HERNS. The molecular and genetic study was not possible to realize remaining hanging the diagnostic confirmation.

Association of the apolipoprotein A-IV: 360 Gln/His polymorphism with cerebrovascular disease, obesity, and depression in a Brazilian elderly population.

The identification of genetic polymorphisms as risk factors for complex diseases can be relevant for their prevention, diagnosis, and prognosis. The apolipoprotein A-IV: 360 Gln/His polymorphism was investigated in 383 elderly individuals, who were participants of a longitudinal study commenced in 1991. The major morbidities that affect elderly people, such as cardiovascular diseases, diabetes, low cognitive function, depression, and obesity, were extensively investigated. DNA was isolated from blood cells, amplified by PCR, and digested with Fnu4HI. In this population the frequency of the His allele was 0.056 and the genotypes were distributed according to Hardy-Weinberg equilibrium. Logistic regression analysis showed a significant association between the presence of His allele and cerebrovascular disease and/or transitory ischemic attack (odds ratio) (OR = 3.070, P = 0.027), obesity (OR = 2.241, P = 0.047), and depression (OR = 2.879, P = 0.005). This study indicates that the presence of the rare allele in elderly people can play a significant role in the occurrence of multifactorial diseases. This is the first study analyzing this polymorphism in elderly people in Brazil. More studies should be encouraged to elucidate the mechanisms involved in these diseases.

Mortality studies in the clarification of gene-environment interactions.

In this paper we review some theories about the process of senescence and death, in particular the theory of accumulation of mutations and the theory of antagonistic pleiotropism. These theories are reviewed in the light of existing scientific evidence, with particular reference to that which points to the possible role of interactions between genes and environment. We conclude that mortality studies, particularly on migrant populations may be an important tool for clarifying this major issue.

A Caucasian family with the 3271 mutation in mitochondrial DNA.

The second most common mutation associated with MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes) in Japan is the 3271 mutation. This mutation was found in a Brazilian family of Portuguese and Italian descent, indicating that this mutation also exists in a race other than Japanese. The propositus had mild clinical manifestations atypical of MELAS, suggesting that patients with the 3271 mutation exhibit heterogeneous phenotypic expression as seen in the 3243 mutation.

Angiotensin converting activity assessed in vivo is increased in hereditary hypertensive rats.

1. The angiotensin converting enzyme (ACE) activity of spontaneously hypertensive (SHR) and spontaneously hypertensive stroke-prone (SHRSP) rats was compared to the ACE activity of normotensive Wistar-Kyoto rats (WKY). 2. ACE activity was assessed indirectly in conscious unrestrained rats using the equipressor response end point to simultaneously calculate the extent of conversion of angiotensin I (AI) to angiotensin II (AII) and the pulmonary degradation of bradykinin (BK). 3. The pulmonary degradation of BK was significantly elevated (99.4%) in SHR rats whereas the elevation was not significant in SHRSP rats (99.2%) compared to WKY rats, even though the pulmonary inactivation of BK in WKY rats was higher (98.6%) than in normotensive Wistar rats (95.6% and 97.5%) previously studied. 4. Blood pressure responsiveness to intra-aortically injected BK (bolus injection and infusion) was markedly increased in SHR and SHRSP rats with no change in reactivity to sodium nitroprusside. 5. Conversion of AI to AII assessed by the equipressor doses of the hormones which produced a 20-mmHg rise in blood pressure was markedly elevated in SHR (86 +/- 4%) and SHRSP (80 +/- 7%) rats when compared to WKY rats (38 +/- 4%). 6. The marked increase in conversion of AI to AII in hypertensive animals, accompanied by an increased pulmonary degradation of BK in SHR rats, suggests that ACE activity is increased in conscious SHR and SHRSP rats and may participate in the genesis of hypertension in this model of genetic hypertension.

Mitochondrial encephalomyopathies with the mutation of the mitochondrial tRNA(Leu(UUR)) gene.

Four families with mitochondrial encephalomyopathy are described. Probands of three families had typical clinical presentations of mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes (MELAS), but the proband of family 4 lacked strokelike episodes. The mitochondrial DNA mutation of tRNA(Leu(UUR)) (transfer ribonucleic acid specific to leucine (UUR codon)) found in MELAS was examined in muscle DNA obtained from biopsy samples of the probands of four families and the maternal relatives of family 2. The mutation was detected in all muscle samples, and the degree of the mutated DNA was 68% to 84% by Southern blot analysis. However, the clinical patterns of the maternal relatives of family 2 were mild and distinctly different from MELAS. The same mutation was also detected in blood-derived DNA samples of all family members examined, including healthy mothers but not fathers, although the degree of mutation did not correlate with the clinical severity. These results confirmed the maternal inheritance of this disease and suggested that the mitochondrial DNA mutation (tRNA(Leu(UUR))) may cause clinical symptoms other than MELAS. The clinical findings of mitochondrial encephalomyopathy should be reinvestigated in terms of the mitochondrial gene mutation; the polymerase chain reaction method will be useful for screening for this mutation of mitochondrial DNA in blood samples.

Angiotensin converting activity assessed in vivo is increased in hereditary hypertensive rats

1. The angiotensin converting enzyme (ACE) activity of spontaneously hypertensive (SHR) and spontaneously hypertensive stroke-prone (SHRSP) rats was compared to the ACE activity of normotensive Wistar-Kyoto rats (WKY). 2. ACE activity was assessed indirectly in conscious unrestrained rats using the equipressor response end point to simultaneously calculate the extent of conversion of angiotensin I (AI) to angiotensin II (AII) and the pulmonary degradation of bradykinin (BK). 3. The pulmonary degradation of BK was significantly elevated (99.4%) in SHR rats whereas the elevation was not significant in SHRSP rats (99.2%) compared to WKY rats, even though the pulmonary inactivation of BK in WKY rats was higher (98.6%) than in normotensive Wistar rats (95.6% and 97.5%) previously studied. 4. Blood pressure responsiveness to intra-aortically injected BK (bolus injection and infusion) was markedly increased in SHR and SHRSP rats with no change in reactivity to sodium nitroprusside. 5. Conversion of AI to AII assessed by the equipressor doses of the hormones which produced a 20-mmHg rise in blood pressure was markedly elevated in SHR (86 +/- 4%) and SHRSP (80 +/- 7%) rats when compared to WKY rats (38 +/- 4%). 6. The marked increase in conversion of AI to AII in hypertensive animals, accompanied by an increased pulmonary degradation of BK in SHR rats, suggests that ACE activity is increased in conscious SHR and SHRSP rats and may participate in the genesis of hypertension in this model of genetic hypertension