Are Ischemic Stroke and Alzheimer's Disease Genetically Consecutive Pathologies?

Complex diseases that affect the functioning of the central nervous system pose a major problem for modern society. Among these, ischemic stroke (IS) holds a special place as one of the most common causes of disability and mortality worldwide. Furthermore, Alzheimer's disease (AD) ranks first among neurodegenerative diseases, drastically reducing brain activity and overall life quality and duration. Recent studies have shown that AD and IS share several common risk and pathogenic factors, such as an overlapping genomic architecture and molecular signature. In this review, we will summarize the genomics and RNA biology studies of IS and AD, discussing the interconnected nature of these pathologies. Additionally, we highlight specific genomic points and RNA molecules that can serve as potential tools in predicting the risks of diseases and developing effective therapies in the future.

Study on Circulating lncRNA Expression Profile in Patients with Cerebral Infarction

To analyze the difference of circulating lncRNA expression profile between the healthy control group and cerebral infarction (CI) patients and to study the epigenetic pathogenesis of CI. Forty patients with acute CI admitted to our hospital from December 2016 to December 2017 were selected as CI group, and 40 healthy people in physical examination center were selected as healthy group. In the CI group, blood samples were taken 5 mL at fasting in the morning (within 72 hours of CI), and the blood samples from healthy group were also taken 5 mL at fasting in the morning. The circulating lncRNA expression profile of serum sample was determined by high-throughput technique, and its difference was analyzed. Bioinformatics technology was used to explore its functional mechanism, and GO, KEGG analysis, and gene expression network were established for lncRNA with significant differences. Next, lnc-ZNF32-1 : 1 and lnc-PCGF5-2 : 1 were selected for further validation of serum lncRNA expression in ACI and NC groups, and ceRNA interaction network analysis, diagnostic specificity, and sensitivity of lnc-ZNF32-1 : 1 and lnc-PCGF5-2 : 1 were conducted. The results showed that compared with the healthy group, there were 512 known lncRNA expressed differentially in the serum of patients with CI, of which 371 were upregulated and 141 were downregulated, and 421 known mRNA expressed differentially, of which 245 were upregulated and 176 downregulated. The differentially expressed mRNA was mainly enriched in 53 gene functions, and the target gene was enriched in the pathways such as HTLV-I infection and pathways in cancer. In addition, the results explored that lnc-ZNF32-1 : 1 and lnc-PCGF5-2 : 1 have potential value for CI diagnosis. In conclusion, the expression profile of lncRNA in CI group was significantly different from that in healthy group, indicating that lncRNA might be closely related to the occurrence, development, and prognosis of CI.

Association of SERPINE1 rs1799889 polymorphism with arterial ischemic stroke in children: a systematic review and meta-analysis

Inherited thrombophilias are well-established predisposing factors for venous thromboembolism, but their role in arterial ischemic stroke (AIS) in children, remains unclear. The association between SERPINE1 rs1799889 polymorphism and AIS in children was evaluated by several studies, whereas the results were conflicting. Thus, we performed this meta-analysis to combine and analyze the available studies in order to provide a more accurate result on the association. PubMed, Scopus, EMBASE, SciELO, MedRxiv, China Biology Medicine Disk, DeepDyve, CNKI, and Web of Science were used to identify all relevant articles published up to 30 November 2020, without any restrictions on ethnicity. Summary odds ratios (ORs) with 95% confidence intervals (CIs) were used to determine the strength of the associations. A total of eight case-control studies with 600 cases and 2,156 controls were selected. No significant association between SERPINE1 rs1799889 polymorphism and AIS in children susceptibility was noted. In the stratified analyses by ethnicity, source of controls, genotyping methods, and age groups, there was still no significant association between SERPINE1 rs1799889 polymorphism and AIS risk in children. This study suggested that SERPINE1 rs1799889 polymorphism might be not related to etiology of AIS in children. Moreover, well-designed, large-scale and multicenter clinical studies are required to improve and validate these results.Supplemental data for this article is available online at https://doi.org/10.1080/15257770.2021.1966798 .

[Application of mathematical modeling methods in the evaluation of severity of ischemic stroke in patients with arterial hypertension]

AIM

To study the possibility of applying methods of mathematical modeling in assessing the severity of ischemic stroke in patients with arterial hypertension.

MATERIAL AND METHODS

The study included 80 patients with ischemic stroke. Blood pressure was measured. Transcutaneous polarography was used to measure the oxygen tension in tissues. Measurements of gas composition of the blood and thickness of the intima-media complex were performed. The level of stable metabolites of nitric oxide in the blood was determined. Measurement of endothelin-1 in the blood was performed by enzyme immunoassay. NIHSS scale was administered to assess the neurological status. Patients were divided into 3 groups according to the degree of neurological deficit. The control group consisted of 10 people without signs of vascular pathology.

RESULTS

An increase in the neurological deficit was accompanied by an increase in the level of endothelin-1, a decrease in the level of stable metabolites of nitric oxide, and a reduction in tissue oxygenation. Discriminative functions were developed for each group of patients using discriminant analysis based on the data obtained in the study. The most statistically significant were two signs: the level of systolic blood pressure and the content of stable metabolites of nitric oxide in the blood.

CONCLUSION

Thus, the imbalance in the indices of endothelium-dependent mechanisms of vascular tone regulation reflect the severity of the condition in ischemic stroke. The method of discriminant analysis allows the creation of sufficiently reliable mathematical models that can have practical significance, and can be used as a method of clarifying the severity of the condition in the acute period of ischemic stroke.

Involvement of polymorphisms of the nerve growth factor and its receptor encoding genes in the etiopathogenesis of ischemic stroke

Background

Despite the important role of the nerve growth factor in the survival and maintenance of neurons in ischemic stroke, data regarding the relationships between variations in the encoding gene and stroke are lacking. In the present study, we evaluated the association of the functional polymorphisms in NGF (rs6330) and NGFR (rs2072446 and rs734194) genes with ischemic stroke in an Armenian population.

Methods

In total, 370 unrelated individuals of Armenian nationality were enrolled in this study. Genomic DNA samples of patients and healthy controls were genotyped using polymerase chain reaction with sequence-specific primers.

Results

The results obtained indicate that the minor allele of rs6330 (P_corr = 2.4E-10) and rs2072446 (P_corr = 0.02) are significantly overrepresented in stroke group, while the minor allele of rs734194 (P_corr = 8.5E-10) was underrepresented in diseased subjects. Single nucleotide polymorphisms in NGF gene (rs6330) and NGFR gene (rs2072446 and rs734194) are associated with the disease. Furthermore, it was shown that the carriage of the NGF rs6330*T minor allele is associated with increased infarct volume and higher risk of recurrent stroke.

Conclusions

In conclusion, our findings suggest that the NGF rs6330*T and NGFR rs2072446*T minor alleles might be nominated as a risk factor for developing ischemic stroke and NGFR rs734194*G minor allele as a protective against this disease at least in Armenian population.

Association between genetic polymorphisms of interleukins and cerebral infarction risk: a meta-analysis

Interleukins (ILs) are the most typical inflammatory and immunoregulatory cytokines. Evidences have shown that polymorphisms in ILs are associated with cerebral infarction risk. However, the results remain inconclusive. The present study was to evaluate the role of ILs polymorphisms in cerebral infarction susceptibility. Relevant case-control studies published between January 2000 and December 2015 were searched and retrieved from the electronic databases of Web of Science, PubMed, Embase and the Chinese Biomedical Database. The odds ratio (OR) with its 95% confidence interval (CI) were employed to calculate the strength of association. A total of 55 articles including 12619 cerebral infarction patients and 14436 controls were screened out. Four ILs (IL-1, IL-6, IL-10 and IL-18) contained nine single nucleotide polymorphisms (SNPs; IL-1α -899C/T, IL-1β -511C/T and IL-1β +3953C/T; IL-6 -174G/C and -572C/G; IL-10 -819C/T and -1082A/G; IL-18 -607C/A and -137G/C). Our result showed that IL-1α -899C/T and IL-18 -607C/A (under all the genetic models), and IL-6 -572C/G (under the allelic model, heterogeneity model and dominant model) were associated with increased the risk of cerebral infarction (P<0.05). Subgroup analysis by ethnicity showed that IL-6 -174G/C polymorphism (under all the five models) and IL-10 -1082A/G polymorphism (under the allelic model and heterologous model) were significantly associated with increased the cerebral infarction risk in Asians. Other genetic polymorphisms were not related with cerebral infarction susceptibility under any genetic models. In conclusion, IL-1α -899C/T, IL-6 -572C/G and IL-18 -607C/A might be risk factors for cerebral infarction development. Further studies with well-designed and large sample size are still required.

[The HIF1a polymorphism is a diagnostic marker of ischemic stroke]

AIM

To study a variant of the C1772T polymorphism of the hypoxia inducible factor-1a (HIF1a) gene as a molecular genetic predictor of increased risk of ischemic stroke.

MATERIAL AND METHODS

The study included patients with ischemic stroke which was confirmed clinically and by MRI (n=1200), the control group consisted of 500 patients without cardiovascular disease. DNA was extracted from the venous blood using the phenol-chloroform method. Determination of alleles was performed using allele-specific RealTime PCR as well as PCR/RFLP diagnosis.

RESULTS

The carriage of one or two copies of the allele T significantly increases the risk of ischemic stroke (OR=1.603, p=0.01). At the same time, the minor allele was not associated with the prognosis of the disease outcome.

CONCLUSION

The results allow us to consider the HIF1 C1772T polymorphism as a new molecular genetic predictor of ischemic stroke.