Single-nucleus transcriptome unveils the role of ferroptosis in ischemic stroke.

Multiple cell death pathways are involved in neuronal death in ischemic stroke (IS). However, the role of different cell death pathways in different cell types has not been elucidated. By analyzing three single-nucleus RNA sequencing (snRNA-seq) data of IS, we first found that a variety of programmed cell death (PCD) -related genes were significantly changed in different cell types. Based on machine learning and virtual gene knockout, we found that ferroptosis related genes, ferritin heavy chain 1 (Fth1) and ferritin light chain (Ftl1), play a key role in IS. Ftl1 and Fth1 can promote microglia activation, as well as the production of inflammatory factors and chemokines. Cell communication analysis showed that activated microglia could enhance chemotactic peripheral leukocyte infiltration, such as macrophages and neutrophils, through Spp1-Cd44 and App-Cd74 signaling, thereby aggravating brain tissue damage. Furthermore, real-time quantitative polymerase chain reaction (RT-qPCR) showed that P2ry12 and Mef2c were significantly decreased in oxygen-glucose deprivation (OGD) group, while Ftl1, Fth1, Apoe, Ctsb, Cd44 and Cd74 were significantly increased in OGD group. Collectively, our findings suggested targeted therapy against microglia Ftl1 and Fth1 might improve the state of microglia, reduce the infiltration of peripheral immune cells and tissue inflammation, and then improve the ischemic brain injury in mouse.

RFX1 regulates foam cell formation and atherosclerosis by mediating CD36 expression.

BACKGROUND AND AIMS: Atherosclerosis (AS) is a continuously low-grade inflammatory disease, and monocyte-derived macrophages play a vital role in AS pathogenesis. Regulatory factor X1 (RFX1) has been reported to participate in differentiation of various cells. Our previous report showed that RFX1 expression in CD14+ monocytes from AS patients was decreased and closely related to AS development. Macrophages mostly derive from monocytes and play an important role in AS plaque formation and stability. However, the functions of RFX1 in the formation of macrophage-derived foam cells and consequent AS development are unclear. METHODS: We explored the effects of RFX1 on oxidation low lipoprotein (ox-LDL)-stimulated foam cell formation and CD36 expression by increasing or silencing Rfx1 expression in mouse peritoneal macrophages (PMAs). The ApoE-/-Rfx1f/f or ApoE-/-Rfx1f/f Lyz2-Cre mice fed a high-fat diet for 24 weeks were used to further examine the effect of RFX1 on AS pathogenesis. We then performed dual luciferase reporter assays to study the regulation of RFX1 for CD36 transcription. RESULTS: Our results demonstrate that RFX1 expression was significantly reduced in ox-LDL induced foam cells and negatively correlated with lipid uptake in macrophages. Besides, Rfx1 deficiency in myeloid cells aggravated atherosclerotic lesions in ApoE-/- mice. Mechanistically, RFX1 inhibited CD36 expression by directly regulating CD36 transcription in macrophages. CONCLUSIONS: The reduction of RFX1 expression in macrophages is a vital determinant for foam cell formation and the initiation of AS, proving a potential novel approach for the treatment of AS disease.

Brain microvascular endothelial cell-derived exosomes transmitting circ_0000495 promote microglial M1-polarization and endothelial cell injury under hypoxia condition.

Human brain microvascular endothelial cells (HBMVECs) and microglia play critical roles in regulating cerebral homeostasis during ischemic stroke. However, the role of HBMVECs-derived exosomes in microglia polarization after stroke remains unknown. We isolated exosomes (Exos) from oxygen glucose deprivation (OGD)-exposed HBMVECs, before added them into microglia. Microglia polarization markers were tested using RT-qPCR or flow cytometry. Inflammatory cytokines were measured with ELISA. Endothelial cell damage was assessed by cell viability, apoptosis, apoptosis-related proteins, oxidative stress, and angiogenic activity using CCK-8, flow cytometry, western blot, ELISA, and endothelial tube formation assay, respectively. We also established middle cerebral artery occlusion (MCAO) mice model to examine the function of circ_0000495 on stroke in vivo. Our study found that HBMVECs-Exos reduced M2 markers (IL-10, CD163, and CD206), increased M1 markers (TNF-α, IL-1ß, and IL-12), CD86-positive cells, and inflammatory cytokines (TNF-α and IL-1ß), indicating the promotion of microglial M1-polarization. Microglial M1-polarization induced by HBMVECs-Exos reduced viability and promoted apoptosis and oxidative stress, revealing the aggravation of endothelial cell damage. However, circ_0000495 silencing inhibited HBMVECs-Exos-induced alterations. Mechanistically, circ_0000495 adsorbed miR-579-3p to upregulate toll-like receptor 4 (TLR4) in microglia; miR-579-3p suppressed HBMVECs-Exos-induced alterations via declining TLR4; furthermore, Yin Yang 1 (YY1) transcriptionally activated circ_0000495 in HBMVECs. Importantly, circ_0000495 aggravated ischemic brain injury in vivo via activating TLR4/nuclear factor-κB (NF-κB) pathway. Collectively, OGD-treated HBMVECs-Exos transmitted circ_0000495 to regulate miR-579-3p/TLR4/NF-κB axis in microglia, thereby facilitating microglial M1-polarization and endothelial cell damage.

Keratinocyte-to-macrophage communication exacerbate psoriasiform dermatitis via LRG1-enriched extracellular vesicles.

Rationale: Macrophage-associated inflammation and keratinocytes excessive proliferation and inflammatory cytokines secretion induced by stimulation play an important role in the progression of psoriasiform dermatitis. However, how these two types of cells communicate remains obscure. Methods: We induced a mouse model with experimental psoriasiform dermatitis by Imiquimod (IMQ). To investigate whether damaged keratinocytes promote macrophage polarization and accelerate skin lesions by releasing extracellular vesicle (EV), purified EV were isolated from the primary epidermis of 5-day IMQ-induced psoriasiform dermatitis model mice, and then fluorescence-labeled the EV with PKH67. The EV was injected into the skin of mice treated with IMQ or vehicle 2 days in situ. In addition, we established a co-culture system of the human monocytic cell line (THP-1) and HaCaT, and THP-1/HaCaT conditioned media culture model in vitro respectively. Subsequently, we evaluated the effect of Leucine-rich α-2-glycoprotein 1 (LRG1)-enriched EV on macrophage activation. Results: We demonstrated macrophages can significantly promote keratinocyte inflammation and macrophage polarization may be mediated by intercellular communication with keratinocytes. Interestingly, IMQ-induced 5-day, keratinocyte-derived EV recruited macrophage and enhanced the progression of skin lesions. Similar to results in vivo, EV released from M5-treated HaCaT significantly promotes Interleukin 1ß (IL-1ß) and Tumor necrosis factor α (TNF-α) expression of THP-1 cells. Importantly, we found that LRG1-enriched EV regulates macrophages via TGF beta Receptor 1 (TGFßR1) dependent process. Conclusion: Our findings indicated a novel mechanism for promoting psoriasiform dermatitis, which could be a potential therapeutic target.

Impact of acute silent ischemic lesions on clinical outcomes of carotid revascularization.

BACKGROUND: Previous literature has established an association between acute silent ischemic lesions (ASILs) and elevated susceptibility to future adverse clinical outcomes. The present study endeavors to scrutinize the prognostic significance of preprocedural ASILs, as detected through diffusion-weighted imaging and apparent diffusion coefficient metrics, in relation to subsequent adverse events-namely, stroke, myocardial infarction, and all-cause death-following carotid revascularization in a cohort of patients with symptomatic carotid stenosis. MATERIALS AND METHODS: Subjects were extracted from a comprehensive retrospective dataset involving symptomatic carotid stenosis cases that underwent carotid revascularization at a tertiary healthcare institution in China, spanning January 2019 to March 2022. Of the 2663 initially screened patients (symptomatic carotid stenosis=1600; asymptomatic carotid stenosis=1063), a total of 1172 individuals with symptomatic carotid stenosis were retained for subsequent analysis. Stratification was implemented based on the presence or absence of ASILs. The primary endpoint constituted a composite measure of in-hospital stroke, myocardial infarction, or all-cause death. Both carotid endarterectomy (CEA) and carotid artery stenting (CAS) treatment modalities were individually subjected to propensity score-matched analyses. RESULTS: Among the 584 subjects who underwent CEA, 91 ASIL-positive and 91 ASIL-negative (NASIL) cases were propensity score-matched. Notably, the ASIL cohort demonstrated a statistically significant augmentation in the risk of primary outcomes relative to the NASIL group [10.99 vs. 1.10%; absolute risk difference, 9.89% (95% CI: 3.12-16.66%); RR, 10.00 (95% CI: 1.31-76.52); P =0.01]. Similarly, within the 588 CAS-treated patients, 107 ASIL-positive and 107 NASIL cases were matched, revealing a correspondingly elevated risk of primary outcomes in the ASIL group [9.35 vs. 1.87%; absolute risk difference, 7.48% (95% CI: 1.39-13.56%); RR, 5.00 (95% CI: 1.12-22.28); P =0.02]. CONCLUSIONS: ASILs portend an elevated risk for grave adverse events postcarotid revascularization, irrespective of the specific revascularization technique employed-be it CEA or CAS. Thus, ASILs may serve as a potent biomarker for procedural risk stratification in the context of carotid revascularization.

Extracellular Vesicles from Neural Stem Cells Carry microRNA-16-5p to Reduce Corticosterone-induced Neuronal Injury in Depression Rats.

OBJECTIVE: Depression is a common mental illness. Neural stem cell-derived extracellular vesicles (NSC-EVs) are involved in repairing neuronal injury. We estimated the mechanism of miR-16-5p in depression rats. METHODS: EVs were extracted from NSCs. The depression rat model was established by corticosterone (CORT) induction and treated with NSC-EVs. The depression behavioral/pathological changes in rats were assessed using forced swimming test, open field test, sucrose consumption test and western blotting. The neuronal apoptosis in hippocampal tissue were detected. CORT-induced PC12 cell model was established. EV uptake by PC12 cells was measured and PC12 cell apoptosis was detected. The downstream targets of miR-16-5p were predicted and verified. The expressions of miR-16-5p and MYB in rats, PC12 cells, and EVs were measured. Functional rescue experiments were conducted to verify the role of miR-16-5p and MYB in PC12 cell apoptosis. RESULTS: CORT induction increased neuronal apoptosis in hippocampal tissue and induced depression-like behaviors in rats, while NSC-EV treatment improved depression-like behaviors and apoptosis in rats. In PC12 cells, NSC-EVs decreased CORT-induced PC12 cell apoptosis. NSC-EVs carried miR-16-5p into PC12 cells. miR-16-5p knockdown in EVs partially reversed the inhibitory effects of NSC-EVs on CORT-induced PC12 cell apoptosis. miR-16-5p targeted to inhibit MYB to repress CORT-induced PC12 cell apoptosis. In vivo experiments further verified that NSC-EVs reduced neuronal injury in CORT-induced depression rats via the miR-16-5p/MYB axis. CONCLUSION: NSC-EVs-mediated alleviation on neuronal injury by carrying miR-16-5p to target MYB was highly likely one of the mechanisms by which NSC-EVs mediated miR-16-5p in neuroprotection of depression rats.

Circular RNA as biomarkers for acute ischemic stroke: A systematic review and meta-analysis.

BACKGROUND: Rapid diagnosis of acute ischemic stroke (AIS) patients is still challenging, and reliable biomarkers are needed. Noncoding RNAs are important for many physiological activities, among which circular RNAs (circRNAs) have been proven to be more tissue-specific and conservative. Many recent studies found the potential of circRNAs as biomarkers for many diseases, including cardiovascular diseases, cancers, and ischemic stroke. This systemic review and meta-analysis aimed to identify circRNAs as potential biomarkers for AIS. METHODS: This study has been prospectively registered in PROSPERO (Registration No. 11 CRD42021288033). Published literature comparing circRNA expression profiles between AIS and non-AIS in human and animal models were retrieved from the articles published by January 2023 in major databases. We descriptively summarized the included studies, conducted meta-analysis under a random effects model, and did bioinformatics analysis including Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. RESULTS: Totally 23 studies were included, reporting 18 distinctive upregulated and 20 distinctive downregulated circRNAs. Diagnostic meta-analysis indicated discriminative ability of the circRNAs. Furthermore, circRNA HECTD1, circRNA DLGAP4, circRNA CDC14A, circRNA SCMH1, and circRNA TLK1 were reported with the same regulation trend in more than one study (animal studies included). GO and KEGG enrichment analyses indicated that the target genes of these five circRNAs were enriched in regulating cell proliferation, apoptosis, and oxidative stress. CONCLUSIONS: This study demonstrates that circRNAs (circRNA HECTD1, circRNA DLGAP4, circRNA CDC14A, circRNA SCMH1, and circRNA TLK1) generally are promising as potential biomarkers for AIS. However, due to the limited number of studies, diagnostic value of individual circRNA could not be validated. More in vitro and in vivo functional studies are needed.

Influence of pre-stroke dependency on safety and efficacy of endovascular therapy: A systematic review and meta-analysis.

Background and purpose: In the landmark trials studying endovascular thrombectomy (EVT), pre-stroke dependent (PSD) patients were generally excluded. This systematic review and meta-analysis aimed to compare the safety and efficacy of EVT between PSD and pre-stroke independent (PSI) patients. Methods: We searched CENTRAL, Embase, and Ovid MEDLINE up to 11 November 2021 for studies assessing PSD and PSI patients, which were separately defined as pre-stroke mRS score >2 or >1, and ≤2 or ≤1 accordingly. Two authors extracted data and assessed the risk of bias. A meta-analysis was carried out using the random-effects model. Adjusted OR and 95% CI were used to estimate adjusted pool effects. The main outcomes included favorable outcomes, successful recanalization, symptomatic intracranial hemorrhage, and 90-day mortality. Results: A total of 8,004 records met the initial search strategy, and ten studies were included in the final decision. Compared with PSImRS≤2, PSDmRS>2 had a lower favorable outcome (OR 0.51; 95% CI, 0.33-0.79) and higher 90-day mortality (OR 3.32; 95% CI, 2.77-3.98). No significant difference was found in successful recanalization and sICH. After adjustment, only 90-day mortality (aOR 1.99; 95% CI, 1.58-2.49) remained significantly higher in PSDmRS>2. Compared with PSImRS≤1, PSDmRS>1 had lower 90-day mortality (OR, 3.10; 95% CI, 1.84-5.24). No significant difference was found regarding the favorable outcome, successful recanalization, and sICH. After adjustment, no significant difference was found in a favorable outcome, but a higher rate of 90-day mortality (aOR, 2.13; 95% CI, 1.66-2.72) remained in PSDmRS>1. Conclusions: PSD does not innately influence the EVT outcomes regarding sICH and favorable outcomes but may increase the risk of 90-day mortality. Until further evidence is available, it is reasonable to suggest EVT for patients with PSD.

Mechanical thrombectomy first versus direct angioplasty or stenting for the treatment of intracranial atherosclerotic stenosis-related large vessel occlusion: protocol for a systematic review and meta-analysis.

INTRODUCTION: Mechanical thrombectomy (MT) using stent retrievers or a direct aspiration first-pass technique has proven to yield better results over intravenous thrombolysis in treating acute ischaemic stroke caused by large vessel occlusion (LVO). However, the treatment of intracranial atherosclerotic stenosis-related LVO remains unclear and has been a critical problem in daily clinical practice, as it can cause a relatively high failure rate for MT. Whether direct angioplasty and/or stenting is clinically feasible and shows advantage in reducing delay to revascularisation with better functional outcome compared with MT with rescue angioplasty and/or stenting remains unclear. This study seeks to provide direct and practical clinical evidence for clinicians. METHODS AND ANALYSIS: The main databases of PubMed, the Cochrane library, Embase and Web of Science will be screened for related studies published after1 January 2015. Primary outcomes include successful recanalisation and 90-day favourable outcome. Secondary outcomes include puncture to revascularisation time, vascular complication (perforation, dissection and vasospasm), intracerebral haemorrhage, hospital-related complications and 90-day mortality. The Newcastle-Ottawa Scale will be adopted to assess risk bias of observational studies. The I 2 statistic will be used to assess heterogeneity. ETHICS AND DISSEMINATION: No primary data of patients are needed. Therefore, ethics approval is unnecessary. The results of this systematic review and meta-analysis will be published in a peer-reviewed journal. PROSPERO REGISTRATION NUMBER: CRD42021268061.

Stress conditions induced circRNAs profile of extracellular vesicles in brain microvascular endothelial cells.

Cerebral ischemia causes hypoxic injury and inflammation, and brain microvascular endothelial cells (BMVECs) dysfunction is an initial stage of blood-brain barrier disruption. Endothelial cells secrete extracellular vesicles (EVs) that are involved in intercellular signal transduction. EVs contain a variety of RNAs, proteins, and metabolites. Circular RNA (circRNA) is a member of the non-coding RNA. The expression profile and potential function of circRNAs in BMVECs are unknown. Here, human BMVECs have undergone hypoxia or TNF-α induction, and the changes in circRNAs were measured by RNA sequencing. A total of 70 circRNAs showed differential expression, including 43 previously unrecorded circRNAs and 27 recorded circRNAs. Since astrocyte end-feet encircle endothelial cells, they are considered the main targets of the EVs from BMVEC. The miRNA sequence data and bioinformatics were used to predict the circRNA-miRNA-mRNA networks in astrocytes. The gene ontology (GO) analysis showed the main downstream targets of circRNAs are DNA transcription regulation and protein kinase-related signaling pathways. These results suggest that altering circRNAs may be a potential therapeutic target for cerebral ischemia induced hypoxic injury and inflammation.

Iron-dependent epigenetic modulation promotes pathogenic T cell differentiation in lupus.

The trace element iron affects immune responses and vaccination, but knowledge of its role in autoimmune diseases is limited. Expansion of pathogenic T cells, especially T follicular helper (Tfh) cells, has great significance to systemic lupus erythematosus (SLE) pathogenesis. Here, we show an important role of iron in regulation of pathogenic T cell differentiation in SLE. We found that iron overload promoted Tfh cell expansion, proinflammatory cytokine secretion, and autoantibody production in lupus-prone mice. Mice treated with a high-iron diet exhibited an increased proportion of Tfh cell and antigen-specific GC response. Iron supplementation contributed to Tfh cell differentiation. In contrast, iron chelation inhibited Tfh cell differentiation. We demonstrated that the miR-21/BDH2 axis drove iron accumulation during Tfh cell differentiation and further promoted Fe2+-dependent TET enzyme activity and BCL6 gene demethylation. Thus, maintaining iron homeostasis might be critical for eliminating pathogenic Th cells and might help improve the management of patients with SLE.

Sex differences in outcomes after mechanical thrombectomy for acute ischemic stroke in the 'real world': protocol for a systematic review and meta-analysis study.

INTRODUCTION: Mechanical thrombectomy (MT) had been regarded as the first-line therapy for acute ischaemic stroke patients. The sex differences in post-MT treatment outcomes were analysed by randomised controlled trial (RCT) studies with inconsistent conclusions. We suggest the results from the real-world data may differ from RCT containing studies. Therefore, the sex difference in non-clinical trial populations needs to be clarified. METHODS AND ANALYSIS: In order to obtain relative studies comprehensively, we will search the main document databases, consisting of Web of Science, Medline in Ovid, Embase in Ovid and Cochrane Library, and trials registers, including Clinical Trails register. The clinical outcomes of real-world studies published between January 2015 and March 2022 will be included. The assessment methods of bias risk will be performed according to study type. The inclusion of studies, evaluation of risk and publication bias, data extraction will be implemented by two reviewers, respectively. The primary outcomes include successful recanalisation and 90-day favourable outcome. Secondary outcomes include vascular complication, hospital-related complications, death during hospital stay and follow-up, and intracerebral haemorrhage. The risk bias of observational studies will be evaluated by Newcastle-Ottawa Scale. I2 statistic will be used to perform the assessment of study heterogeneity. ETHICS AND DISSEMINATION: With no need of ethics approval in this review, results in this review ground on public data. The results of the study will be eventually presented at international conferences or in a related journal. PROSPERO REGISTRATION NUMBER: CRD42021242597.

Gomisin J attenuates cerebral ischemia/reperfusion injury by inducing anti-apoptotic, anti-inflammatory, and antioxidant effects in rats.

Ischemic stroke is one of the leading causes of morbidity and mortality in humans. Cerebral ischemia-reperfusion (CIR) injury serves as a leading cause of stroke. Schisandra chinensis is a well-known Chinese traditional medicine. In this study, we explored the role of Gomisin J (GJ), a compound of S. chinensis, in CIR using a middle cerebral artery occlusion/reperfusion rat model and the possible mechanisms. We identified that GJ reduced neurological scores, cerebral infarction, and water content in the I/R rat brain. Importantly, GJ rescued I/R treatment-reduced neuron survival in the hippocampus, inhibited apoptosis of ischemic tissues in I/R rats, increased B-cell lymphoma-extra-large (Bcl-XL) expression, and reduced the levels of cleaved caspase-3, Bax, cyclooxygenase-2, nuclear factor kappa-B, and nitric oxide in I/R rat brain tissues. Furthermore, GJ treatment enhanced nuclear factor E2 related factor 2 (Nrf2) translocation, heme oxygenase-1 (HO-1) expression, superoxide dismutase and glutathione peroxidase activities, and glutathione level. Overall, GJ treatment GJ attenuates CIR injury by inducing anti-apoptotic, antioxidant, and anti-inflammatory effects in vivo.

Ultraviolet light induces HERV expression to activate RIG-I signalling pathway in keratinocytes.

Skin inflammation and photosensitivity are common in lupus erythematosus (LE) patients, and ultraviolet (UV) light is a known trigger of skin and possibly systemic inflammation in systemic lupus erythematosus (SLE) and discoid lupus erythematosus (DLE) patients. Type I interferons (IFN) are upregulated in LE skin after UV exposure; however, the mechanisms to explain UVB-induced inflammation remain unclear. Here, we demonstrated that UVB irradiation-induced activation of human endogenous retroviruses (HERVs) plays a major role in the immune response. UVB-induced HERV-associated dsRNA transcription and subsequent activation of the innate antiviral RIG-I/MDA5/IRF7 pathway led to downstream transcription of interferon-stimulated genes, which promotes UVB-induced apoptosis and proliferation inhibition in keratinocytes through RIG-I and MDA5 pathways. Our findings indicate that UVB irradiation induces HERV-dsRNA overexpression, and the dsRNA-sensing innate immunity pathway promotes type I IFN production, which may be a potential mechanism of skin inflammatory response and skin lesion of SLE/DLE.

Broad and dynamic neurochemical alterations in the brain of alcoholic rats.

Ethanol is the active ingredient in alcoholic beverages. As ethanol consumption increases from zero to very high, it is still unknown which metabolites are present at different times and which are essential to normal functioning. In this article, we used an intermittent-access 20% ethanol drinking paradigm to make Wistar male rats voluntarily drink large amounts of ethanol for 10, 20, 30, and 50 days, respectively. A hydrogen-1 nuclear magnetic resonance approach was used to investigate the time-dependent neurochemical metabolites spectra in the hippocampus, striatum, nucleus accumbens and prefrontal cortex. Multivariate pattern recognition techniques were used to analyze the hydrogen-1 nuclear magnetic resonance spectra data. Metabolic profiling was obtained, differentiating the ethanol-treated and control rats. The ethanol-affected metabolites disrupted processes associated with neurotransmitters, oxidative stress, energy metabolism and amino acids. Together, our findings demonstrate broad, dynamic, and time-dependent endogenous metabolic alterations in rats treated with ethanol.

Discovery of a novel AR/HDAC6 dual inhibitor for prostate cancer treatment.

Androgen receptor (AR) and histone deacetylase 6 (HDAC6) are important targets for cancer therapy. Given that both AR antagonists and HDAC6 inhibitors modulate AR signaling, a novel AR/HDAC6 dual inhibitor is investigated for its anticancer effects in castration-resistant prostate cancer (CRPC). Zeta55 inhibits nuclear translocation of AR and suppresses androgen-induced PSA and TMPRSS2 expression. Meanwhile, Zeta55 selectively inhibits HDAC6 activity, leading to AR degradation. Zeta55 reduces the growth of AR-overexpressing VCaP prostate cancer cells both in vitro and in a CRPC xenograft model. These results provide preclinical proof of principle for Zeta55 as a promising therapeutic in prostate cancer treatment.

UHRF1 downregulation promotes T follicular helper cell differentiation by increasing BCL6 expression in SLE.

BACKGROUND: Transcription factor B cell lymphoma 6 (BCL6) is a master regulator of T follicular helper (Tfh) cells, which play a crucial role in the pathogenesis of systemic lupus erythematosus (SLE). However, the mechanisms by which BCL6 expression is regulated are poorly understood. Ubiquitin-like with PHD and RING finger domains 1 (UHRF1) is an important epigenetic factor that regulates DNA methylation and histone modifications. In the present study, we assessed whether UHRF1 can regulate BCL6 expression and influence the differentiation and proliferation of Tfh cells. RESULTS: Compared to healthy controls, the mean fluorescence intensity of UHRF1 (UHRF1-MFI) in Tfh cells from SLE patients was significantly downregulated, whereas that of BCL6 (BCL6-MFI) was significantly upregulated. In vitro, UHRF1 knockdown led to BCL6 overexpression and promoted Tfh cell differentiation. In contrast, UHRF1 overexpression led to BCL6 downregulation and decreased Tfh cell differentiation. In vivo, conditional UHRF1 gene knockout (UHRF1-cKO) in mouse T cells revealed that UHRF1 depletion can enhance the proportion of Tfh cells and induce an augmented GC reaction in mice treated with NP-keyhole limpet hemocyanin (NP-KLH). Mechanistically, UHRF1 downregulation can decrease DNA methylation and H3K27 trimethylation (H3K27me3) levels in the BCL6 promoter region of Tfh cells. CONCLUSIONS: Our results demonstrated that UHRF1 downregulation leads to increased BCL6 expression by decreasing DNA methylation and H3K27me3 levels, promoting Tfh cell differentiation in vitro and in vivo. This finding reveals the role of UHRF1 in regulating Tfh cell differentiation and provides a potential target for SLE therapy.

Antegrade or Retrograde Approach for the Management of Tandem Occlusions in Acute Ischemic Stroke: A Systematic Review and Meta-Analysis.

Background: Acute ischemic stroke (AIS) caused by tandem intracranial and extracranial occlusions is not rare. However, optimal strategy between antegrade (extracranial first) or retrograde (intracranial first) approaches still remains elusive. This systematic review and meta-analysis aim to compare the two approaches to provide updated clinical evidence of strategy selection. Methods: PubMed, Ovid, Web of Science, and the Cochrane Library were searched for literature comparing antegrade and retrograde approaches for patients with AIS with concomitant tandem occlusions. Outcomes including successful reperfusion [Throbolysis in Cerebral Infarction (TICI) 2b-3] and 90-day favorable outcome [modified Rankin Scale (mRS) 0-2], any intracerebral hemorrhage, symptomatic intracerebral hemorrhage, procedural complications, and mortality were evaluated. The risk of bias was assessed using the Newcastle-Ottawa Scale and illustrated in the Funnel plot. Heterogeneity was assessed by I 2 statistic. Subgroup and sensitivity analyses were also performed. Results: A total of 11 studies accounting 1,517 patients were included. 831 (55%) patients were treated with an antegrade approach and 686 (45%) patients were treated with the retrograde approach. A higher successful reperfusion rate was achieved in retrograde group than that of antegrade group [83.8 vs. 78.0%; odds ratio (OR): 0.63, 95% CI: 0.40-0.99, p = 0.04]. 90-day favorable outcome (mRS 0-2 at 90 days) also showed significantly higher in retrograde group compared with antegrade group (47.3 vs. 40.2%; OR: 0.72, 95% CI: 0.58-0.89, p = 0.002). The incidence of any intracranial hemorrhage (ICH), symptomatic intracranial hemorrhage, 90-day mortality, and other complications did not differ between two groups. Conclusion: In AIS with tandem occlusions, the retrograde approach might achieve a higher successful reperfusion rate and better functional outcome with a comparable safety profile when compared with an antegrade approach. Further prospective controlled studies with more meticulous design and a higher level of evidence are needed to confirm these results. Systematic Review Registration: "PROSPERO" database (CRD 42020199093), https://www.crd.york.ac.uk/PROSPERO/.

miR-18b attenuates cerebral ischemia/reperfusion injury through regulation of ANXA3 and PI3K/Akt signaling pathway.

Recent, research has displayed that the disorders of miR-18b are related to ischemic stroke. Here, we aimed to investigate the underlying neuroprotective mechanism of miR-18b in cerebral ischemia/reperfusion (I/R) injury. Oxygen-glucose deprivation/reperfusion (OGDR) model in vitro and middle cerebral artery occlusion (MCAO) model in vivo were established to simulate cerebral I/R injury. RT-PCR, western blotting, CCK-8, TUNEL, and TTC staining assays were applied in this study to explore the effect of miR-18b on cerebral I/R injury. Results displayed that miR-18b expression was reduced after cerebral I/R injury. Besides, miR-18b showed neuroprotective effects on cerebral I/R injury both in vitro and in vivo, These neuroprotective effects included promoting cell viability, decreasing cell apoptosis, reducing the production of inflammatory cytokines in SH-SY 5Y cells after OGDR and depressing MCAO-induced infarct size, neurological deficits and apoptotic cells in mice. Moreover, miR-18b negatively regulated ANXA3 expression, and its neuroprotection on cerebral I/R injury was overturned by ANXA3. Additionally, increasing miR-18b or decreasing ANXA3 promoted the activation of the PI3K/Akt signaling pathway in SH-SY 5Y cells after cerebral I/R injury. In conclusion, these data indicate that miR-18b protects against cerebral I/R injury by inhibiting ANXA3 and activating PI3K/Akt pathway, which provides a promising therapeutic target for ischemic stroke therapy.