Neuroprotective effects of p53/microRNA‑22 regulate inflammation and apoptosis in subarachnoid hemorrhage

Neuroprotective Effects of Piceatannol on Olfactory Bulb Injury after Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) accounts for 5% of all stroke cases and is responsible for significant permanent brain and neurological damage within the first few days. Loss of smell is one of those neurological disorders following olfactory bulb injury after SAH. Olfaction plays a critical role in several aspects of life. The primary underlying mechanism of olfactory bulb (OB) injury and loss of smell after SAH remains unknown. Piceatannol (PIC), a natural stilbene, possesses anti-inflammatory and anti-apoptotic effects against various diseases. In this study, we aimed to investigate the potential therapeutic effects of PIC on OB injury following SAH at molecular mechanism based on SIRT1, inflammatory (TNF-α, IL1-β, NF-κB, IL-6, TLR4), and apoptosis (p53, Bax, Bcl-2, caspase-3)-related gene expression markers and histopathology level; 27 male Wistar Albino rats were used in a pre-chiasmatic subarachnoid hemorrhage model. Animals were divided into groups (n = 9): SHAM, SAH, and PIC. Garcia's neurological examination, brain water content, RT-PCR, histopathology, and TUNEL analyses were performed in all experimental groups with OB samples. Our results indicated that PIC administration significantly suppressed inflammatory molecules (TNF-α, IL-6, IL1-β, TLR4, NF-κB, SIRT1) and apoptotic molecules (caspase-3, p53, Bax). We also evaluated edema levels and cell damage in OB injury after SAH. Ameliorative effects of PIC are also observed at the histopathology level. Garcia's neurological score test performed a neurological assessment. This study is the first to demonstrate the neuroprotective effects of PIC on OB injury after SAH. It suggests that PIC would be a potential therapeutic agent for alleviating OB injury after SAH.

The mechanism and relevant mediators associated with neuronal apoptosis and potential therapeutic targets in subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH) is a dominant cause of death and disability worldwide. A sharp increase in intracranial pressure after SAH leads to a reduction in cerebral perfusion and insufficient blood supply for neurons, which subsequently promotes a series of pathophysiological responses leading to neuronal death. Many previous experimental studies have reported that excitotoxicity, mitochondrial death pathways, the release of free radicals, protein misfolding, apoptosis, necrosis, autophagy, and inflammation are involved solely or in combination in this disorder. Among them, irreversible neuronal apoptosis plays a key role in both short- and long-term prognoses after SAH. Neuronal apoptosis occurs through multiple pathways including extrinsic, mitochondrial, endoplasmic reticulum, p53 and oxidative stress. Meanwhile, a large number of blood contents enter the subarachnoid space after SAH, and the secondary metabolites, including oxygenated hemoglobin and heme, further aggravate the destruction of the blood-brain barrier and vasogenic and cytotoxic brain edema, causing early brain injury and delayed cerebral ischemia, and ultimately increasing neuronal apoptosis. Even there is no clear and effective therapeutic strategy for SAH thus far, but by understanding apoptosis, we might excavate new ideas and approaches, as targeting the upstream and downstream molecules of apoptosis-related pathways shows promise in the treatment of SAH. In this review, we summarize the existing evidence on molecules and related drugs or molecules involved in the apoptotic pathway after SAH, which provides a possible target or new strategy for the treatment of SAH.

New Mechanisms and Targets of Subarachnoid Hemorrhage: A Focus on Mitochondria

Spontaneous subarachnoid hemorrhage (SAH) accounts for 5-10% of all strokes and is a subtype of hemorrhagic stroke that places a heavy burden on health care. Despite great progress in surgical clipping and endovascular treatment for ruptured aneurysms, cerebral vasospasm (CVS) and delayed cerebral ischemia (DCI) threaten the long-term outcomes of patients with SAH. Moreover, there are limited drugs available to reduce the risk of DCI and adverse outcomes in SAH patients. New insight suggests that early brain injury (EBI), which occurs within 72 h after the onset of SAH, may lay the foundation for further DCI development and poor outcomes. The mechanisms of EBI mainly include excitotoxicity, oxidative stress, neuroinflammation, blood-brain barrier (BBB) destruction, and cellular death. Mitochondria are a double-membrane organelle, and they play an important role in energy production, cell growth, differentiation, apoptosis, and survival. Mitochondrial dysfunction, which can lead to mitochondrial membrane potential (Δψm) collapse, overproduction of reactive oxygen species (ROS), release of apoptogenic proteins, disorders of mitochondrial dynamics, and activation of mitochondria-related inflammation, is considered a novel mechanism of EBI related to DCI as well as post-SAH outcomes. In addition, mitophagy is activated after SAH. In this review, we discuss the latest perspectives on the role of mitochondria in EBI and DCI after SAH. We emphasize the potential of mitochondria as therapeutic targets and summarize the promising therapeutic strategies targeting mitochondria for SAH.

Dysregulated microRNA expression in rheumatoid arthritis families-a comparison between rheumatoid arthritis patients, their first-degree relatives, and healthy controls

OBJECTIVE

Recent studies have demonstrated an altered expression of certain microRNAs in patients with rheumatoid arthritis (RA) as well as their first-degree relatives (FDRs) compared to healthy controls (HCs), suggesting a role of microRNA in the progression of the disease. To corroborate this, a set of well-characterized RA families originating from northern Sweden were analyzed for differential expression of a selected set of microRNAs.

METHOD

MicroRNA was isolated from frozen peripheral blood cells obtained from 21 different families and included 26 RA patients, 22 FDRs, and 21 HCs. Expression of the selected microRNAs miR-22-3p, miR-26b-5p, miR-34a-3p, miR-103a-3p, miR-142-3p, miR-146a-5p, miR-155, miR-346, and miR-451a was determined by a two-step quantitative real-time polymerase chain reaction (qRT-PCR). Statistical analysis including clinical variables was applied.

RESULTS

Out of the nine selected microRNAs that previously have been linked to RA, we confirmed four after adjusting for age and gender, i.e., miR-22-3p (p = 0.020), miR-26b-5p (p = 0.018), miR-142-3p (p = 0.005), and miR-155 (p = 0.033). Moreover, a significant trend with an intermediate microRNA expression in FDR was observed for the same four microRNAs. In addition, analysis of the effect of corticosteroid use showed modulation of miR-103a-3p expression.

CONCLUSIONS

We confirm that microRNAs seem to be involved in the development of RA, and that the expression pattern in FDR is partly overlapping with RA patients. The contribution of single microRNAs in relation to the complex network including all microRNAs and other molecules is still to be revealed. Key Points • Expression levels of miR-22-3p, miR-26b-5p, miR-142-3p, and miR-155 were significantly altered in RA patients compared to those in controls. • In first-degree relatives, a significant trend with an intermediate microRNA expression in FDR was observed for the same four microRNAs.

Development of an Early Prediction Model for Subarachnoid Hemorrhage With Genetic and Signaling Pathway Analysis

Subarachnoid hemorrhage (SAH) is devastating disease with high mortality, high disability rate, and poor clinical prognosis. It has drawn great attentions in both basic and clinical medicine. Therefore, it is necessary to explore the therapeutic drugs and effective targets for early prediction of SAH. Firstly, we demonstrate that LCN2 can effectively intervene or treat SAH from the perspective of cell signaling pathway. Next, three potential genes that we explored have been validated by manually reviewed experimental evidences. Finally, we turn out that the SAH early ensemble learning predictive model performs better than the classical LR, SVM, and Naïve-Bayes models.

Plasma and CSF miRNA dysregulations in subarachnoid hemorrhage reveal clinical courses and underlying pathways

BACKGROUND

Subarachnoid hemorrhage (SAH) is fatal and detrimental to quality of life. Clinically, options for monitoring are often limited, potentially missing subtle neurological changes especially in low-grade patients. This article reviewed miRNA dysregulation in SAH and analyzed their functional and clinical relevance.

METHODS

With adherence to PRISMA guideline, PubMed, EMBASE, GEO and ArrayExpress were searched comprehensively for relevant clinical and animal models. Datasets were analyzed and enriched by experimentally validated targets and multiple databases using R v3.4.2, Ingenuity Pathway Analysis, and miRPath v3.0.

RESULTS

Among 1926 search results, 18 studies were screened for full-text assessment. The 8 included studies revealed a marked miRNA dysregulation after SAH. 2 datasets were retrieved. In both serum and CSF, different miRNA profiles were associated with Early Brain Injury, Delayed Cerebral Infarction, vasospasm and prognosis. In CSF, a dramatic restructure of inter-miRNA correlation matrix was observed. Enrichment analysis revealed strong association (1) BBB instability, with adherens, extra-cellular matrix, actin cytoskeleton, integrin, TGF-β, Wnt/β-catenin etc; (2) autophagy, with MTORC1, HIF-1, ULK2, and FoxO etc; (3) apoptosis, with PI3K-Akt, p53, and AMPK. We analyzed common miRNAs across SAH and cerebral ischemia. They were related to neuronal differentiation, oxidation stress, apoptosis, angiogenesis, Alzheimer's disease, NMDA-induced calcium influx, excitotoxicity and NO production.

CONCLUSIONS

Clinical progression of SAH is associated with different miRNA fingerprints. They carry neuro-pathological relevance and can be a potential biomarker which compliments SAH management.