MicroRNA Let-7i Is a Promising Serum Biomarker for Post-stroke Cognitive Impairment and Alleviated OGD-Induced Cell Damage in vitro by Regulating Bcl-2

Post-stroke cognitive impairment: exploring molecular mechanisms and omics biomarkers for early identification and intervention

Post-stroke cognitive impairment (PSCI) is a major stroke consequence that has a severe impact on patients' quality of life and survival rate. For this reason, it is especially crucial to identify and intervene early in high-risk groups during the acute phase of stroke. Currently, there are no reliable and efficient techniques for the early diagnosis, appropriate evaluation, or prognostication of PSCI. Instead, plenty of biomarkers in stroke patients have progressively been linked to cognitive impairment in recent years. High-throughput omics techniques that generate large amounts of data and process it to a high quality have been used to screen and identify biomarkers of PSCI in order to investigate the molecular mechanisms of the disease. These techniques include metabolomics, which explores dynamic changes in the organism, gut microbiomics, which studies host-microbe interactions, genomics, which elucidates deeper disease mechanisms, transcriptomics and proteomics, which describe gene expression and regulation. We looked through electronic databases like PubMed, the Cochrane Library, Embase, Web of Science, and common databases for each omics to find biomarkers that might be connected to the pathophysiology of PSCI. As all, we found 34 studies: 14 in the field of metabolomics, 5 in the field of gut microbiomics, 5 in the field of genomics, 4 in the field of transcriptomics, and 7 in the field of proteomics. We discovered that neuroinflammation, oxidative stress, and atherosclerosis may be the primary causes of PSCI development, and that metabolomics may play a role in the molecular mechanisms of PSCI. In this study, we summarized the existing issues across omics technologies and discuss the latest discoveries of PSCI biomarkers in the context of omics, with the goal of investigating the molecular causes of post-stroke cognitive impairment. We also discuss the potential therapeutic utility of omics platforms for PSCI mechanisms, diagnosis, and intervention in order to promote the area's advancement towards precision PSCI treatment.

Exosomal miR-let-7c-5p is involved in the cognitive function of type 2 diabetes mellitus patients by interleukin 10: A cross-sectional study

BACKGROUND

Interleukin (IL)-10 plays a notable role in the inflammatory-associated mild cognitive impairment (MCI). We aimed to investigate whether IL-10 and its upstream factors exert an impact on MCI in type 2 diabetes mellitus (T2DM) patients.

METHODS

A total of 117 T2DM patients were recruited and divided into Control group and MCI group based on the presence or absence of MCI. Clinical parameters were collected. The Montreal Cognitive Assessment (MoCA) was conducted for global cognitive function. Digit Span Test (DST), Verbal Fluency Test (VFT), and Trail Making Test-B (TMTB) were used to evaluate the executive functions of the diabetic patients. Trail Making Test-A (TMTA) was performed to examine the information processing speed function. Patients' scene memory was examined by Logical Memory Test (LMT). After the baseline data were compared, correlation and regression analyses were performed to explore the relationship among IL-10, miR-let-7c-5p and cognitive function.

RESULTS

Compared to 80 patients in the control group, 37 patients in the MCI group exhibited lower IL-10 in plasma and higher miR-let-7c-5p levels in exosomes from plasma. The IL-10 level was negatively associated with MoCA. Likewise, miR-let-7c-5p levels were negatively correlated with IL-10 levels and MoCA. Elevated miR-let-7c-5p levels and decreased IL-10 levels are risk factors for MCI in T2DM patients. Increased miR-let-7c-5p and downregulated IL-10 may influence VFT and TMTB, respectively, associated with executive function.

CONCLUSIONS

We demonstrated that IL-10 is correlated to the executive function of T2DM patients. Decreased IL-10 may result from the regulation of miR-let-7c-5p in exosomes.

Neuronal Responses to Ischemia: Scoping Review of Insights from Human-Derived In Vitro Models

Translation of neuroprotective treatment effects from experimental animal models to patients with cerebral ischemia has been challenging. Since pathophysiological processes may vary across species, an experimental model to clarify human-specific neuronal pathomechanisms may help. We conducted a scoping review of the literature on human neuronal in vitro models that have been used to study neuronal responses to ischemia or hypoxia, the parts of the pathophysiological cascade that have been investigated in those models, and evidence on effects of interventions. We included 147 studies on four different human neuronal models. The majority of the studies (132/147) was conducted in SH-SY5Y cells, which is a cancerous cell line derived from a single neuroblastoma patient. Of these, 119/132 used undifferentiated SH-SY5Y cells, that lack many neuronal characteristics. Two studies used healthy human induced pluripotent stem cell derived neuronal networks. Most studies used microscopic measures and established hypoxia induced cell death, oxidative stress, or inflammation. Only one study investigated the effect of hypoxia on neuronal network functionality using micro-electrode arrays. Treatment targets included oxidative stress, inflammation, cell death, and neuronal network stimulation. We discuss (dis)advantages of the various model systems and propose future perspectives for research into human neuronal responses to ischemia or hypoxia.

Let7i A key player and a promising biomarker in diseases

MicroRNAs (miRNAs) are endogenous non-coding single-stranded small RNAs that regulate gene expression by recognizing homologous sequences and interfering with transcriptional, translational or epigenetic processes. MiRNAs are involved in a variety of disease processes, and regulate the physiological and pathological status of diseases by modulating target cell activity, migration, invasion, apoptosis, autophagy and other processes. Among them, let-7i is highly expressed in various systems, which participates in the process of tumors, cardiovascular and cerebrovascular diseases, fibrotic diseases, inflammatory diseases, neurodegenerative diseases and other diseases, and plays a positive or negative regulatory role in these diseases through different signal pathways and key molecules. Moreover, it can be used as an early diagnosis and prognostic marker for a variety of diseases and become a potential therapeutic target. As a biomarker, let-7i is frequently tested in combination with other miRNAs to diagnose multiple diseases and evaluate the clinical treatment or prognosis.

Circulating MicroRNAs and Extracellular Vesicle-Derived MicroRNAs as Predictors of Functional Recovery in Ischemic Stroke Patients: A Systematic Review and Meta-Analysis

Stroke accounts for the second leading cause of death and a major cause of disability, with limited therapeutic strategy in both the acute and chronic phases. Blood-based biomarkers are intensively researched and widely recognized as useful tools to predict the prognoses of patients confronted with therapeutically limited diseases. We performed a systematic review of the circulating biomarkers in IS patients with prognostic value, with a focus on microRNAs and exosomes as predictive biomarkers of motor and cognitive recovery. We identified 63 studies, totalizing 72 circulating biomarkers with prognostic value in stroke recovery, as follows: 68 miRNAs and exosomal-miRNAs being identified as predictive for motor recovery after stroke, and seven biomarkers being predictive for cognitive recovery. Twelve meta-analyses were performed using effect sizes (random-effects and fixed-effects model). The most significant correlation findings obtained after pooling were with miR-21, miR-29b, miR-125b-5p, miR-126, and miR-335. We identified several miRNAs that were correlated with clinical outcomes of stroke severity and recovery after ischemic stroke, providing predictive information on motor and cognitive recovery. Based on the current state of research, we identified serum miR-9 and neutrophil miR-29b as the most promising biomarkers for in-depth follow-up studies, followed by serum miR-124 and plasma miR-125b.

Intranasal Administration of Agomir-let-7i Improves Cognitive Function in Mice with Traumatic Brain Injury

Overcoming the lack of drugs for the treatment of traumatic brain injury (TBI) has long been a major challenge for the pharmaceutical industry. MiRNAs have emerged as potential targets for progress assessment and intervention against TBI. The brain-enriched miRNA let-7i has been proposed as an ideal candidate biomarker for TBI, but its regulatory roles in brain injury remain largely unknown. Here, we find that the expression of let-7i is significantly downregulated in the early stages of a hippocampal stab wound injury. The noninvasive intranasal administration of let-7i agomir significantly improves cognitive function and suppresses neuroinflammation, glial scar formation, and neuronal apoptosis in TBI mice. Mechanically, STING is a direct downstream target of let-7i after brain injury. Furthermore, the intranasal delivery of let-7i agomir can also effectively inhibit STING and is beneficial for inflammation resolution and neuronal survival in a mouse model of pial vessel disruption stroke. Consequently, let-7i agomir is a promising candidate for clinical application as a chemically engineered oligonucleotides-based therapeutic for brain injury.

Gut Microbiome Signatures Are Biomarkers for Cognitive Impairment in Patients With Ischemic Stroke

Post-stroke cognitive impairment (PSCI) is a common neuropsychiatric complication of stroke. Mounting evidence has demonstrated a connection between gut microbiota (GM) and neuropsychiatric disease. Our previous study revealed the changes in the GM in a mouse model of vascular dementia. However, the characteristic GM of PSCI remains unclear. This study aimed to characterize the GM of PSCI and explored the potential of GM as PSCI biomarkers. A total of 93 patients with ischemic stroke were enrolled in this study. The patients were divided into two groups according to their MoCA scores 3 months after stroke onset. Clinical data and biological variables were recorded. GM composition was analyzed using 16S ribosomal RNA sequencing, and the characteristic GM was identified by linear discriminant analysis Effect Size (Lefse). Our results showed that Proteobacteria was highly increased in the PSCI group compared with the post-stroke non-cognitive impairment (PSNCI) group, the similar alterations were also observed at the class, order, family, and genus levels of Proteobacteria. After age adjustments, the abundance of Firmicutes, and its members, including Clostridia, Clostridiales, Lachnospiraceae, and Lachnospiraceae_other, were significantly decreased in the age-matched PSCI group compared with the PSNCI group. Besides, the GM was closely associated with MoCA scores and the risk factors for PSCI, including higher baseline National Institute of Health Stroke Scale score, higher homocysteine (Hcy) level, higher prevalence of stroke recurrence, leukoaraiosis, and brain atrophy. The KEGG results showed the enriched module for folding, sorting and degradation (chaperones and folding catalysts) and the decreased modules related to metabolisms of cofactors and vitamins, amino acid, and lipid in PSCI patients. A significant correlation was observed between PSCI and the abundance of Enterobacteriaceae after adjustments (P = 0.035). Moreover, the receiver operating characteristic (ROC) models based on the characteristic GM and Enterobacteriaceae could distinguish PSCI patients from PSNCI patients [area under the curve (AUC) = 0.840, 0.629, respectively]. Our findings demonstrated that the characteristic GM, especially Enterobacteriaceae, might have the ability to predict PSCI in post-stroke patients, which are expected to be used as clinical biomarkers of PSCI.