Protective effects and regulatory pathways of melatonin in traumatic brain injury mice model: Transcriptomics and bioinformatics analysis.

Traumatic brain injury (TBI) is the leading cause of disability and mortality globally. Melatonin (Mel) is a neuroendocrine hormone synthesized from the pineal gland that protects against TBI. Yet, the precise mechanism of action is not fully understood. In this study, we examined the protective effect and regulatory pathways of melatonin in the TBI mice model using transcriptomics and bioinformatics analysis. The expression profiles of mRNA, long non-coding RNA (lncRNA), microRNA (miRNA), and circular RNA (circRNA) were constructed using the whole transcriptomes sequencing technique. In total, 93 differentially expressed (DE) mRNAs (DEmRNAs), 48 lncRNAs (DElncRNAs), 59 miRNAs (DEmiRNAs), and 59 circRNAs (DEcircRNAs) were identified by the TBI mice with Mel treatment compared to the group without drug intervention. The randomly selected coding RNAs and non-coding RNAs (ncRNAs) were identified by quantitative real-time polymerase chain reaction (qRT-PCR). To further detect the biological functions and potential pathways of those differentially expressed RNAs, Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses were executed. In our research, the regulatory network was constructed to show the relationship of lncRNA-RBPs. The lncRNA-mRNA co-expression network was established based on the Pearson coefficient to indicate the expression correlations. Moreover, the DEcircRNA-DEmiRNA-DEmRNA and DElncRNA-DEmiRNA-DEmRNA regulatory networks were constructed to demonstrate the regulatory relationship between ncRNAs and mRNA. Finally, to further verify our predicted results, cytoHubba was used to find the hub gene in the synaptic vesicle cycle pathway, and the expression level of SNAP-25 and VAMP-2 after melatonin treatment were detected by Western blotting and immunofluorescence. To sum up, these data offer a new insight regarding the molecular effect of melatonin treatment after TBI and suggest that the high-throughput sequencing and analysis of transcriptomes are useful for studying the drug mechanisms in treatment after TBI.

A novel circular RNA, circIgfbp2, links neural plasticity and anxiety through targeting mitochondrial dysfunction and oxidative stress-induced synapse dysfunction after traumatic brain injury.

Traumatic brain injury (TBI) can lead to different neurological and psychiatric disorders. Circular RNAs (circRNAs) are highly expressed in the nervous system and enriched in synapses; yet, the underlying role and mechanisms of circRNAs in neurological impairment and dysfunction are still not fully understood. In this study, we investigated the expression of circRNAs and their relation with neurological dysfunction after TBI. RNA-Seq was used to detect differentially expressed circRNAs in injured brain tissue, revealing that circIgfbp2 was significantly increased. Up-regulated hsa_circ_0058195, which was highly homologous to circIgfbp2, was further confirmed in the cerebral cortex specimens and serum samples of patients after TBI. Moreover, correlation analysis showed a positive correlation between hsa_circ_0058195 levels and the Self-Rating Anxiety Scale scores in these subjects. Furthermore, knockdown of circIgfbp2 in mice relieved anxiety-like behaviors and sleep disturbances induced by TBI. Knockdown of circIgfbp2 in H2O2 treated HT22 cells alleviated mitochondrial dysfunction, while its overexpression reversed the process. Mechanistically, we discovered that circIgfbp2 targets miR-370-3p to regulate BACH1, and down-regulating BACH1 alleviated mitochondrial dysfunction and oxidative stress-induced synapse dysfunction. In conclusion, inhibition of circIgfbp2 alleviated mitochondrial dysfunction and oxidative stress-induced synapse dysfunction after TBI through the miR-370-3p/BACH1/HO-1 axis. Thus, circIgfbp2 might be a novel therapeutic target for anxiety and sleep disorders after TBI.

CircLphn3 protects the blood-brain barrier in traumatic brain injury.

Circular RNAs (circRNAs) are a new and large group of non-coding RNA molecules that are abundantly expressed in the central nervous system. However, very little is known about their roles in traumatic brain injury. In this study, we firstly screened differentially expressed circRNAs in normal and injured brain tissues of mice after traumatic brain injury. We found that the expression of circLphn3 was substantially decreased in mouse models of traumatic brain injury and in hemin-treated bEnd.3 (mouse brain cell line) cells. After overexpressing circLphn3 in bEnd.3 cells, the expression of the tight junction proteins, ZO-1, ZO-2, and occludin, was upregulated, and the expression of miR-185-5p was decreased. In bEnd.3 cells transfected with miR-185-5p mimics, the expression of ZO-1 was decreased. Dual-luciferase reporter assays showed that circLphn3 bound to miR-185-5p, and that miR-185-5p bound to ZO-1. Additionally, circLphn3 overexpression attenuated the hemin-induced high permeability of the in vitro bEnd.3 cell model of the blood-brain barrier, while miR-185-5p transfection increased the permeability. These findings suggest that circLphn3, as a molecular sponge of miR-185-5p, regulates tight junction proteins' expression after traumatic brain injury, and it thereby improves the permeability of the blood-brain barrier. This study was approved by the Animal Care and Use Committee of Chongqing Medical University of China (approval No. 2021-177) on March 22, 2021.

A novel mechanism linking ferroptosis and endoplasmic reticulum stress via the circPtpn14/miR-351-5p/5-LOX signaling in melatonin-mediated treatment of traumatic brain injury.

Traumatic brain injury (TBI) can lead to disability or devastating consequences with few established treatments. Although ferroptosis has been shown to be involved in TBI, the underlying mechanism was rarely known. Melatonin has been indicated to exhibit neuroprotective activities. However, the anti-ferroptotic effects of melatonin on TBI have not yet to be elucidated. We aimed to investigate whether ferroptosis was induced in humans after TBI and whether ferroptosis inhibition by melatonin could protect against blood-brain barrier (BBB) damage after TBI in vivo and in vitro. Circular RNAs (circRNAs) are highly expressed in the brain. For the first time, differentially expressed circRNA after melatonin treatment for TBI were detected by RNA sequencing. We found that lipid peroxidation was induced in humans after TBI, while melatonin significantly improved brain function of mice after TBI and alleviated ferroptosis and endoplasmic reticulum (ER) stress in vivo and in vitro. A total of 1826 differentially expressed circRNAs were found (fold change >2, Q < 0.01), including 921 down-regulated and 905 up-regulated circRNAs in the injured brain tissues of TBI mice receiving melatonin treatment. Mechanistically, melatonin administration reduced the level of circPtpn14 (mmu_circ_0000130), which functioned by acting as a miR-351-5p sponge to positively regulate the expression of the ferroptosis-related 5-lipoxygenase (5-LOX). Moreover, circPtpn14 overexpression partly abolished the inhibitory effects of melatonin on ferroptosis. Collectively, our findings provide the first evidence that melatonin could exert anti-ferroptotic and anti-ER stress effects in brain injury by alleviating lipid peroxidation via the circPtpn14/miR-351-5p/5-LOX signaling.

Combination of the EP and Anti-PD-1 Pathway or Anti-CTLA-4 for the Phase III Trial of Small-Cell Lung Cancer: A Meta-Analysis.

The morbidity and mortality of lung cancer remain one of the highest among multiple cancers, respectively. Small-Cell Lung Cancer (SCLC) accounts for around 10%-15% of all lung cancers. Approximately two-thirds of the diagnosed SCLCs are in extensive stage (ES). Decades later, we still rely on the same traditional regimen with etoposide and platinum (EP) as the mainstay of treatment with poor prognosis. This meta-analysis aims to assess the effect of adding Immune Checkpoint Inhibitors (CPIs) such as (ipilimumab, atezolizumab, pembrolizumab, and durvalumab) to the traditional EP regimen for small-cell lung cancer extensive stage (ES-SCLC). We searched through PubMed looking for studies that compare between EP and CPIs, with EP alone, and only Phase III randomized controlled trials were considered eligible for this study. A total of 3645 papers were the results of the initial search, and only 4 studies met our criteria. Each investigator extracted the data independently using the PRISMA MODEL (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guideline. Each author used a prespecified sheet. The primary endpoint was to calculate OS (overall survival) and PFS (progression-free survival) hazard ratios for both arms. We found that adding EP plus CPIs increased both OS (HR, 95% CI 0.80 [0.70, 0.93], P = 0.0001, I 2 = 49%) and PFS (HR95% CI 0.81 [0.74, 0.88], P < 0.00001, I 2 = 0%). On the other hand, ORR (overall response rate) was not affected by the addition of CPIs to EP compared to EP alone, and the same was true for adverse events. To conclude, CTLA-4 alone is not encouraging, but PD-1/PD-L1 adds survival benefits. A combined treatment regimen shows to be more effective, improving overall survival rate Durvalumab and atezolizumab showed improvement for OS, but pembrolizumab and ipilimumab did not show a significant increase of OS over EP; however, pembrolizumab showed significant prolongation of the disease-free period.