Emerging Potential of Immediate Early Response Gene X-1 in Cardiovascular and Metabolic Diseases

The mouse retinal pigment epithelium mounts an innate immune defense response following retinal detachment

The retinal pigment epithelium (RPE) maintains photoreceptor viability and function, completes the visual cycle, and forms the outer blood-retinal barrier (oBRB). Loss of RPE function gives rise to several monogenic retinal dystrophies and contributes to age-related macular degeneration. Retinal detachment (RD) causes separation of the neurosensory retina from the underlying RPE, disrupting the functional and metabolic relationships between these layers. Although the retinal response to RD is highly studied, little is known about how the RPE responds to loss of this interaction. RNA sequencing (RNA-Seq) was used to compare normal and detached RPE in the C57BL6/J mouse. The naïve mouse RPE transcriptome was compared to previously published RPE signature gene lists and from the union of these 14 genes (Bmp4, Crim1, Degs1, Gja1, Itgav, Mfap3l, Pdpn, Ptgds, Rbp1, Rnf13, Rpe65, Slc4a2, Sulf1 and Ttr) representing a core signature gene set applicable across rodent and human RPE was derived. Gene ontology enrichment analysis (GOEA) of the mouse RPE transcriptome identified expected RPE features and functions, such as pigmentation, phagocytosis, lysosomal and proteasomal degradation of proteins, and barrier function. Differentially expressed genes (DEG) at 1 and 7 days post retinal detachment (dprd) were defined as mRNA with a significant (padj≤0.05) fold change (FC) of 0.67 ≥ FC ≥ 1.5 in detached versus naïve RPE. The RPE transcriptome exhibited dramatic changes at 1 dprd, with 2297 DEG identified. The KEGG pathways and biological process GO groups related to innate immune responses were significantly enriched. Lipocalin 2 (Lcn2) and several chemokines were upregulated, while numerous genes related to RPE functions, such as pigment synthesis, visual cycle, phagocytosis, and tight junctions were downregulated at 1 dprd. The response was largely transient, with only 18 significant DEG identified at 7 dprd, including upregulation of complement gene C4b. Validation studies confirmed RNA-Seq results. Thus, the RPE quickly downregulates cell-specific functions and mounts an innate immune defense response following RD. Our data demonstrate that the RPE contributes to the inflammatory response to RD and may play a role in attraction of immune cells to the subretinal space.

Systemic immune inflammation index and system inflammation response index are potential biomarkers of atrial fibrillation among the patients presenting with ischemic stroke

Background

Chronic inflammatory disorders in atrial fibrillation (AF) contribute to the onset of ischemic stroke. Systemic immune inflammation index (SIII) and system inflammation response index (SIRI) are the two novel and convenient measurements that are positively associated with body inflammation. However, little is known regarding the association between SIII/SIRI with the presence of AF among the patients with ischemic stroke.

Methods

A total of 526 ischemic stroke patients (173 with AF and 353 without AF) were consecutively enrolled in our study from January 2017 to June 2019. SIII and SIRI were measured in both groups. Logistic regression analysis was used to analyse the potential association between SIII/SIRI and the presence of AF. Finally, the correlation between hospitalization expenses, changes in the National Institutes of Health Stroke Scale (NIHSS) scores and SIII/SIRI values were measured.

Results

In patients with ischemic stroke, SIII and SIRI values were significantly higher in AF patients than in non-AF patients (all p < 0.001). Moreover, with increasing quartiles of SIII and SIRI in all patients, the proportion of patients with AF was higher than that of non-AF patients gradually. Logistic regression analyses demonstrated that log-transformed SIII and log-transformed SIRI were independently associated with the presence of AF in patients with ischemic stroke (log-transformed SIII: odds ratio [OR]: 1.047, 95% confidence interval CI = 0.322–1.105, p = 0.047; log-transformed SIRI: OR: 6.197, 95% CI = 2.196–17.484, p = 0.001). Finally, a positive correlation between hospitalization expenses, changes in the NIHSS scores and SIII/SIRI were found, which were more significant in patients with AF (all p < 0.05).

Conclusions

Our study suggests SIII and SIRI are convenient and effective measurements for predicting the presence of AF in patients with ischemic stroke. Moreover, they were correlated with increased financial burden and poor short-term prognosis in AF patients presenting with ischemic stroke.

Gene expression profiles of mitochondria-endoplasmic reticulum tethering in human gingival fibroblasts in response to periodontal pathogens

OBJECTIVE

The current study aimed to elucidate the potential involvement of mitochondria-endoplasmic reticulum contact genes in the pathogenesis of periodontal disease by monitoring levels of contact associated genes including Mitofusion 1 (MFN1) and MFN2, inositol 1,4,5-trisphosphate receptor (IP3R), chaperone glucose-regulated protein 75 (GRP75), sigma non-opioid intracellular receptor 1 (SIGMAR1) and phosphate and tensin homolog induced putative kinase 1 (PINK1) in human gingival fibroblasts in response to periodontal pathogens Fusobacterium nucleatum (F. nucleatum) and Porphyromonas gingivalis (P. gingivalis) in vitro.

DESIGN

Primary human gingival fibroblasts were exposed to live cultures of P. gingivalis (W83; ATCC BAA-308) and F. nucleatum (subsp. Polymorphum; ATCC 10953) alone or in combination for 4 h at a 50 or 200 multiplicity of infection. Escherichia coli lipopolysaccharide (10 μg/mL) exposure was used as a positive control. Gene expression levels of contact genes (MFN1, MFN2, IP3R, GRP75, SIGMAR1 and PINK1) as well as a proinflammatory cytokine, Tumor necrosis factor-α (TNF-α), and the apoptosis associated gene, Immediate early response 3 (IER3), were evaluated by reverse transcription polymerase chain reaction analysis.

RESULTS

MFN1, GRP75, IP3R and PINK1 were significantly upregulated by P. gingivalis with or without F. nucleatum. Only P. gingivalis with F. nucleatum caused a significant upregulation of SIGMAR1. TNF-α and IER3 gene expression positively correlated with the contact-associated gene expression changes.

CONCLUSION

F. nucleatum and P. gingivalis alone or in combination may differentially dysregulate the gene expression levels of contact-associated genes in human gingival fibroblasts. These host-microbiome interactions may mechanistically be important in the pathogenesis of periodontal disease.