Inflammatory cytokines and stroke and its subtypes: a genetic correlation and two-sample Mendelian randomization study

IntroductionThe causal relationship between inflammatory factors and stroke subtypes remains unclear. This study aimed to analyze the causal relationship between 41 inflammatory factors and these two factors using Mendelian randomization (MR).MethodsWe performed a two-sample MR analysis to assess the causal effects of 41 inflammatory cytokines on stroke and its subtypes and conducted a genome-wide association study (GWAS) data. The inverse-variance weighted (IVW) method was adopted as the main MR method, and we performed a series of two-sample Mendelian randomizations and related sensitivity analyses.ResultsThe study indicated some suggestive evidences: using the IVW approach, we found that lower possible levels of IL-4 were positively associated with the occurrence of stroke (odds ratio [OR] = 0.93, 95% confidence interval [CI]: 0.88–0.99, p = 0.014), higher interleukin (IL)-1β, IL-12p70 levels may be positively correlated with the occurrence of stroke (OR = 1.09, 95% CI: 1.01–1.18, p = 0.027; OR = 1.08, 95% CI: 1.02–1.15, p = 0.015). For IS, results showed that lower levels of IL-4, tumor necrosis factor-related apoptosis-inducing ligand were positively associated with the occurrence of possible ischemic stroke (IS) (OR = 0.92, 95% CI: 0.87–0.98, p = 0.006; OR = 0.95, 95% CI: 0.91–1.00, p = 0.031), higher levels of IL-1β, IL-12p70 and vascular endothelial growth factor (VEGF) may be positively correlated with the occurrence of IS (OR = 1.09, 95% CI: 1.00–1.19, p = 0.042; OR = 1.07, 95% CI: 1.01–1.15, p = 0.035; OR = 1.06, 95% CI: 1.00–1.12, p = 0.034). Our findings suggest that decreased IL-17 levels could potentially be linked to a higher likelihood of intracerebral hemorrhage (ICH) (OR = 0.51, 95% CI: 0.28–0.93, p = 0.028). For subtypes of stroke, IS and ICH, higher levels of growth regulated oncogene-α, beta nerve growth factor, IL-18, macrophage colony-stimulating factor, and induced protein 10 upregulated the risk factors while lower levels of IL-2ra and IL-17 upregulated the risk factors.ConclusionIn summary, our research validated that inflammatory markers have a pivotal impact on the development of stroke and could potentially offer a fresh approach to treating this condition

Aquaporin-3 Attenuates Oxidative Stress-Induced Nucleus Pulposus Cell Apoptosis Through Regulating the P38 MAPK Pathway

Background/Aims: Previous studies have shown that oxidative damage is a main contributor to disc nucleus pulposus (NP) cell apoptosis. Aquaporin-3 (AQP-3) facilitates reactive oxygen species (ROS) scavenging and thus alleviates oxidative injury in other cells. This study aims to investigate the role and mechanism of AQP-3 in regulating NP cell apoptosis under oxidative damage. Methods: Rat NP cells were treated with H2O2 for 48 hours, while control NP cells were free of H2O2. Recombinant AQP-3 lentiviral vectors were used to investigate the effect of enhanced AQP-3 expression levels in NP cells. NP cell apoptosis was assessed by flow cytometry, caspase-3 activity, gene expression of apoptosis-related molecules (Bax, Bcl-2 and caspase-3), and protein expression of cellular apoptosis markers (cleaved PARP and cleaved caspase-3). Additionally, intracellular ROS content and activity of the p38 MAPK pathway were evaluated. Results: Compared with the control NP cells, oxidative damage in the treatment cells significantly increased cell apoptosis ratios and caspase-3 activity, upregulated gene expression of Bax and caspase-3, downregulated gene expression of Bcl-2, and increased protein expression of cleaved PARP and cleaved caspase-3, as well as increased intracellular ROS content and activity of the p38 MAPK pathway. However, AQP-3 overexpression partly alleviated cell apoptosis, decreased intracellular ROS content, and inhibited the p38 MAPK pathway in NP cells under oxidative damage. Conclusion: Oxidative damage can significantly downregulate AQP-3 expression. Enhancing AQP-3 expression in NP cells partly attenuates cellular apoptosis through regulating the p38 MAPK pathway under oxidative damage

Salmon Calcitonin Exerts an Antidepressant Effect by Activating Amylin Receptors

Depressive disorder is defined as a psychiatric disease characterized by the core symptoms of anhedonia and learned helplessness. Currently, the treatment of depression still calls for medications with high effectiveness, rapid action, and few side effects, although many drugs, including fluoxetine and ketamine, have been approved for clinical usage by the Food and Drug Administration (FDA). In this study, we focused on calcitonin as an amylin receptor polypeptide, of which the antidepressant effect has not been reported, even if calcitonin gene-related peptides have been previously demonstrated to improve depressive-like behaviors in rodents. Here, the antidepressant potential of salmon calcitonin (sCT) was first evaluated in a chronic restraint stress (CRS) mouse model of depression. We observed that the immobility duration in CRS mice was significantly increased during the tail suspension test and forced swimming test. Furthermore, a single administration of sCT was found to successfully rescue depressive-like behaviors in CRS mice. Lastly, AC187 as a potent amylin receptor antagonist was applied to investigate the roles of amylin receptors in depression. We found that AC187 significantly eliminated the antidepressant effects of sCT. Taken together, our data revealed that sCT could ameliorate a depressive-like phenotype probably via the amylin signaling pathway. sCT should be considered as a potential therapeutic candidate for depressive disorder in the future

Production of Recombinant Human DNA Polymerase Delta in a Bombyx mori Bioreactor

Eukaryotic DNA polymerase δ (pol δ) plays a crucial role in chromosomal DNA replication and various DNA repair processes. It is thought to consist of p125, p66 (p68), p50 and p12 subunits. However, rigorous isolation of mammalian pol δ from natural sources has usually yielded two-subunit preparations containing only p125 and p50 polypeptides. While recombinant pol δ isolated from infected insect cells have some problems of consistency in the quality of the preparations, and the yields are much lower. To address these deficiencies, we have constructed recombinant BmNPV baculoviruses using MultiBac system. This method makes the generation of recombinant forms of pol δ containing mutations in any one of the subunits or combinations thereof extremely facile. From about 350 infected larvae, we obtained as much as 4 mg of pol δ four-subunit complex. Highly purified enzyme behaved like the one of native form by rigorous characterization and comparison of its activities on poly(dA)/oligo(dT) template-primer and singly primed M13 DNA, and its homogeneity on FPLC gel filtration. In vitro base excision repair (BER) assays showed that pol δ plays a significant role in uracil-intiated BER and is more likely to mediate LP BER, while the trimer lacking p12 is more likely to mediate SN BER. It seems likely that loss of p12 modulates the rate of SN BER and LP BER during the repair process. Thus, this work provides a simple, fast, reliable and economic way for the large-scale production of human DNA polymerase δ with a high activity and purity, setting up a new platform for our further research on the biochemical properties of pol δ, its regulation and the integration of its functions, and how alterations in pol δ function could contribute to the etiology of human cancer or other diseases that can result from loss of genomic stability

The Integrative Effects of Leading by Example and Follower Traits in Public Goods Game: A Multilevel Study

As an important way to understand leadership based on voluntary contribution mechanisms, the importance of leading by example to teamwork is becoming more and more evident in recent years. However, existing theories based on signaling and reciprocity perspectives, respectively, provide incomplete theoretical explaining. This study adds clarity by conducting a cross-level study that indicates a possible integrative framework of both signaling and reciprocity perspective on leading by example. Results were using data gathered from 130 Chinese college students, which were allocated into one baseline group and three experimental groups. A hierarchical model was used to examine the effects of leading by example on different levels. It is found that leading by example has positive effects on the cooperation of followers on both the group level and the individual level. Risk attitudes have positive effects on the cooperation of followers while trust attitudes have negative effects. Our findings suggest that both leading by example and personal traits significantly influence cooperation but on different levels. It also reminds us that a more systematic way to understand leadership is needed

Defective autophagy is associated with neuronal injury in a mouse model of multiple sclerosis

Neurodegeneration, along with inflammatory demyelination, is an important component of multiple sclerosis (MS) pathogenesis. Autophagy is known to play a pivotal role in neuronal homeostasis and is implicated in several neurodegenerative disorders. However, whether autophagy is involved in the mechanisms of neuronal damage during MS remains to be investigated. Experimental autoimmune encephalomyelitis (EAE), an in vivo model of MS, was induced in female C57BL/6 mice by immunization with myelin oligodendrocyte glycoprotein p35-55. After that, autophagic flux in the spinal cord of mice was evaluated by detection of LC3-II and Beclin1 protein expressions. EAE mice were then administered with rapamycin and 3-methyladenine (3-MA) for 10 days. Afterward, the changes in LC3-II, Beclin1, and p62 expression, number of infiltrated inflammatory cells, demyelinated lesion area, and neuronal damage, as well as clinical scores, were assessed. Further, apoptotic cell rate and apoptosis-related protein expressions were monitored. We observed an impaired autophagic flux and increased neuronal damage in the spinal cords of EAE mice. We also found that rapamycin, an autophagy inducer, mitigated EAE-induced autophagy decrease, inflammation, demyelination and neuronal injury, as well as the abnormal clinical score. In addition, rapamycin suppressed cell apoptosis, and decreased Bax/Bcl-2 ratio and cleaved caspase-3 expression. Conversely, the effect of autophagy inhibitor 3-MA on EAE mice resulted in completely opposite results. These results indicated that autophagy deficiency, at least in part, contributed to EAE-induced neuronal injury and that pharmacological modulation of autophagy might be a therapeutic strategy for MS

Fibrinogen‐to‐Albumin Ratio and Clinical Outcomes in Patients With Large Artery Atherosclerosis Stroke

Background A high fibrinogen‐to‐albumin ratio (FAR), a novel inflammatory marker, is considered to be a prognostic marker in vascular diseases. However, the association of FAR with large artery atherosclerosis (LAA) stroke is still unknown. This study was conducted to evaluate the association between FAR levels and clinical outcomes in patients with acute LAA stroke. Methods and Results A total of 809 patients within 72 hours of LAA stroke were included and followed up to 1 year. FAR was calculated as fibrinogen (g/L)/albumin (g/L). The associations of FAR with clinical outcomes were assessed by multivariate Cox regression or logistic regression analysis. Clinical outcomes included stroke recurrence, all‐cause death, poor functional outcome (modified Rankin Scale score 3–6), and dependence (modified Rankin Scale score 3–5). Among the 809 patients with acute LAA stroke, the median FAR was 0.075 (interquartile range, 0.064–0.087). At 1 year, 103 (12.7%) patients had stroke recurrence, 105 (13.0%) had poor functional outcome, 76 (9.8%) had dependence, and 29 (3.6%) had died. After adjusting for all confounding risk factors, a high FAR level was associated with stroke recurrence (hazard ratio, 2.57 [95% CI, 1.32–5.02]), poor functional outcome (odds ratio, 3.30 [95% CI, 1.57–6.94]), and dependence (odds ratio, 3.49 [95% CI, 1.49–8.19]). Conclusions A high FAR level was associated with an increased risk of stroke recurrence, poor functional outcome, and dependence in patients with acute LAA stroke