Novel insights into the neuroendocrine control of inflammation: the role of GR and PARP1

Microglia activation and inflammation in hippocampus attenuates memory and mood functions during experimentally induced diabetes in rat

Incidence of cognitive and emotional alterations are reportedly two times more in diabetic patients than in non-diabetic population with hitherto unexplained causation and mechanism. Purview of the hippocampus functional diversity sanctions the accessibility and the necessity to investigate the regional neuro-immunological aspects of neurodegeneration and related functional alterations following diabetes. We examined the possible involvement of microglia activation, macrophage response, oxidative stress and inflammatory stature in both ventral and dorsal hippocampus of rats rendered diabetic by a single injection of streptozotocin (STZ; 45 mg/ kg body weight; intraperitoneal). Cognitive and behavioural alterations were studied using open field test (locomotor activity), elevated plus maze (anxiety), Barnes maze (spatial cognition) and T maze (working memory) at 2nd, 4th, 6th, 8th, 10th and 12th week post diabetic confirmation. Oxidative stress was investigated via measuring the level of lipid peroxidation biochemically. Scenario of microglia activation, macrophage response and inflammation was gauged using qualitative and quantitative analysis. Pronounced macrophage expression and activation directed microglia phenotypic switching was prominent in both ventral and dorsal hippocampus indicating the impact of oxidative stress following diabetes in hippocampus. The resultant inflammatory response was also progressive and persistent in both ventral and dorsal hippocampus parallel to the altered cognitive, locomotor ability and anxiety behaviour in diabetic rats. Conclusively, present data not only comprehends the microglia, macrophage physiology and related immune response in functionally different hippocampal regions associated cognitive and behavioural deficits, but also offers a suggestive region-specific cellular mechanism pathway for developing an imminent therapeutic approach during particular diabetes deficits.

CircTLK1 modulates sepsis-induced cardiomyocyte apoptosis via enhancing PARP1/HMGB1 axis-mediated mitochondrial DNA damage by sponging miR-17-5p

Introduction

Septic cardiomyopathy is a common complication of sepsis with high morbidity and mortality, but lacks specific therapy. This study aimed to reveal the role of circTLK1 and its potential mechanisms in septic cardiomyopathy.

Materials and Methods

The in vitro and in vivo models of septic cardiomyopathy were established. Cell viability and apoptosis were detected by CCK8, TUNEL and flow cytometry, respectively. LDH, CK, SOD, MDA, ATP, 8‐OHdG, NAD+/NADH ratio, ROS level, mitochondrial membrane potential and cytochrome C distribution were evaluated using commercial kits. qRT‐PCR and western blotting were performed to detect RNA and protein levels. Mitochondrial DNA (mtDNA) copy number and transcription were assessed by quantitative PCR. Dual‐luciferase assay, RNA immunoprecipitation and co‐immunoprecipitation were performed to verify the interaction between circTLK1/PARP1 and miR‐17‐5p.

Results

CircTLK1, PARP1 and HMGB1 were up‐regulated in the in vitro and in vivo models of septic cardiomyopathy. CircTLK1 inhibition restrained LPS‐induced up‐regulation of PARP1 and HMGB1. Moreover, circTLK1 knockdown repressed sepsis‐induced mtDNA oxidative damage, mitochondrial dysfunction and consequent cardiomyocyte apoptosis by inhibiting PARP1/HMGB1 axis in vitro and in vivo. In addition, circTLK1 enhanced PARP1 expression via sponging miR‐17‐5p. Inhibition of miR‐17‐5p abolished the protective effects of circTLK1 silencing on oxidative mtDNA damage and cardiomyocyte apoptosis.

Conclusion

CircTLK1 sponged miR‐17‐5p to aggravate mtDNA oxidative damage, mitochondrial dysfunction and cardiomyocyte apoptosis via activating PARP1/HMGB1 axis during sepsis, indicating that circTLK1 may be a putative therapeutic target for septic cardiomyopathy.

The Role of Genetic Polymorphism in the Formation of Arterial Hypertension, Type 2 Diabetes and their Comorbidity

BACKGROUND

Hereditary component plays a significant role in the formation of insulin resistance (IR) - one of the pathogenetic links of arterial hypertension (AH) and type 2 diabetes mellitus (DM2). However, the genetic predisposition to IR can not be realized and does not manifest itself clinically in the absence of appropriate factors of the environment (excessive nutrition, low physical activity, etc.).

OBJECTIVE

The review summarizes the results of studies which describe the contribution of genetic polymorphism to the formation and progression of AH, DM2 and their comorbidity in various populations.

RESULTS

In many studies, it has been established that genetic polymorphism of candidate genes is influenced by the formation, course and complication of AH and DM2. According to research data, the modulating effect of polymorphism of some genetic markers of AH and DM2 on metabolism and hemodynamics has been established. The results of numerous studies have shown a higher frequency of occurrence of AH and DM2, as well as their more severe course with adverse genetic polymorphisms. At the same time, the role of genetic polymorphism in the formation of AH and DM2 differs in different populations.

CONCLUSION

Contradictory data on the influence of gene polymorphisms on the formation of AH and DM2 in different populations, as well as a small number of studies on the combined effects of several polymorphisms on the formation of comorbidity, determine the continuation of research in this direction.

Microemboli alter the acute stress response and cause prolonged expression of MCP-1 in the hippocampus

Microvascular ischemia is linked to cardiovascular disease pathology, as well as alterations in mood and cognition. Ischemia activates the hypothalamic-pituitary-adrenal (HPA) axis and through chronic activation, alters HPA axis function. Dysregulation of the HPA axis can lead to the chronic release of glucocorticoids, a hyper-inflammatory cerebral response, cell damage, and changes in behavior. Although the interactions between injury and HPA axis activity have been established in global ischemia, HPA-related repercussions of diffuse ischemic damage and subsequent inflammation have not been assessed. The current study used a rat model of microsphere embolism (ME) ischemia to test the hypothesis that microvascular ischemia would lead to long term alterations in HPA axis function and inflammatory activity. Furthermore, given the pro-inflammatory nature of chronic stress, we assessed the implications of chronic stress for gene expression of inflammatory factors and key components of the glucocorticoid receptor response, following microvascular ischemia. Results indicated that ME altered the response to an acute stress fourteen days following ME injury and increased hippocampal expression of monocyte chemoattractant protein 1 (Mcp-1) as long as 4 weeks following ME injury, without concomitant effects on gene expression of the glucocorticoid receptor or its co-chaperones. Furthermore, no exacerbative effects of chronic stress exposure were observed following ME injury beyond the effects of ME injury alone. Together, these results indicate that ME injury is sufficient to alter both HPA axis activity and cerebral inflammation for a prolonged period of time following injury.

Identification of proteins associated with an IFNγ-responsive promoter by a retroviral expression system for enChIP using CRISPR

Isolation of specific genomic regions retaining molecular interactions is essential for comprehensive identification of molecules associated with the genomic regions. Recently, we developed the engineered DNA-binding molecule-mediated chromatin immunoprecipitation (enChIP) technology for purification of specific genomic regions. Here, we developed a retroviral expression system for enChIP using CRISPR. We showed that the target genomic locus can be purified with high efficiency by using this system. We also showed that contamination of potential off-target sites is negligible by using this system if the guide RNA (gRNA) for the target site has a sufficiently long unique sequence in its seed sequence. enChIP combined with stable isotope labeling using amino acids in cell culture (SILAC) analysis identified proteins whose association with the interferon (IFN) regulatory factor-1 (IRF-1) promoter region increases in response to IFNγ stimulation. The list of the associated proteins contained many novel proteins in the context of IFNγ-induced gene expression as well as proteins related to histone deacetylase complexes whose involvement has been suggested in IFNγ-mediated gene expression. Finally, we confirmed IFNγ-induced increased association of the identified proteins with the IRF-1 promoter by ChIP. Thus, our results showed that the retroviral enChIP system using CRISPR would be useful for biochemical analysis of genome functions including transcription and epigenetic regulation.

Palladium-catalyzed cyclization of benzamides with arynes: application to the synthesis of phenaglydon and N-methylcrinasiadine

N-Methyl or methoxy substituted benzamides reacted with benzynes in the presence of a palladium catalyst, yielding tricyclic N-methyl or N-methoxy substituted phenanthridinones.